Food Canning Guide
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Complete Guide to
Home Canning
Guide 1
Principles of
Home Canning
United States
Department of
Agriculture
Cooperative
State Research,
Education and
Extension Service
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Principles of Home Canning
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Guide 1
Principles of Home Canning
Table of Contents
Section .................................................................................................................... Page
Why can foods? ..................................................................................................................1-5
How canning preserves foods ..............................................................................................1-5
Ensuring safe canned foods .................................................................................................1-6
Food acidity and processing methods .......................................................................1-8
Process adjustments at high altitudes .....................................................................1-10
Equipment and methods not recommended ...........................................................1-10
Ensuring high-quality canned foods ...................................................................................1-11
Maintaining color and avor in canned food ...........................................................1-11
Advantages of hot packing .....................................................................................1-12
Controlling headspace ...........................................................................................1-13
Jars and lids ......................................................................................................................1-13
Jar cleaning and preparation ..................................................................................1-14
Sterilization of empty jars .......................................................................................1-14
Lid selection, preparation, and use .........................................................................1-15
Recommended canners ....................................................................................................1-17
Boiling-water canners ...........................................................................................1-18
Using boiling-water canners ..................................................................................1-18
Pressure canners ...................................................................................................1-19
Using pressure canners...........................................................................................1-21
Selecting the correct processing time ................................................................................1-22
Example of using tables for determining proper process time ...................................1-23
Cooling jars ......................................................................................................................1-25
Testing jar seals ................................................................................................................1-25
Reprocessing unsealed jars ................................................................................................1-26
Storing canned food .........................................................................................................1-26
Identifying and handling spoiled canned food ....................................................................1-26
Preparing pickled and fermented foods ..............................................................................1-27
Ingredients ............................................................................................................1-28
Pickles with reduced salt content ............................................................................1-28
Firming agents .......................................................................................................1-28
Preventing spoilage ................................................................................................1-29
Preparing butters, jams, jellies, and marmalades ................................................................1-29
Ingredients ............................................................................................................1-29
Jams and jellies with reduced sugar .........................................................................1-30
Preventing spoilage ................................................................................................1-30
Methods of making jams and jellies ........................................................................1-30
Canned foods for special diets ...........................................................................................1-31
Canning without sugar ...........................................................................................1-31
Canning without salt (reduced sodium) ..................................................................1-31
Canning fruit-based baby foods ........................................................................................1-31
How much should you can? ..............................................................................................1-32
Glossary of Terms ............................................................................................................1-33
Index of Foods .................................................................................................................1-36
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Why can foods?
Canning can be a safe and economical way to preserve quality food at home. Disregarding
the value of your labor, canning homegrown food may save you half the cost of buying
commercially canned food. Canning favorite and special products to be enjoyed by family and
friends is a fullling experience and a source of pride for many people.
Many vegetables begin losing some of their vitamins when harvested. Nearly half the vitamins
may be lost within a few days unless the fresh produce is cooled or preserved. Within 1 to 2
weeks, even refrigerated produce loses half or more of some of its vitamins. The heating pro-
cess during canning destroys from one-third to one-half of vitamins A and C, thiamin,
and riboavin. Once canned, additional losses of these sensitive vitamins are from 5 to 20
percent each year. The amounts of other vitamins, however, are only slightly lower in canned
compared with fresh food. If vegetables are handled properly and canned promptly after
harvest, they can be more nutritious than fresh produce sold in local stores.
The advantages of home canning are lost when you start with poor quality fresh foods; when
jars fail to seal properly; when food spoils; and when avors, texture, color, and nutrients
deteriorate during prolonged storage.
The information and guides that follow explain many of these problems and recommend ways
to minimize them.
How canning preserves foods
The high percentage of water in most fresh foods makes them very perishable. They spoil or
lose their quality for several reasons:
• growth of undesirable microorganisms—bacteria, molds, and yeasts,
• activity of food enzymes,
• reactions with oxygen,
• moisture loss.
Microorganisms live and multiply quickly on the surfaces of fresh food and on the inside of
bruised, insect-damaged, and diseased food. Oxygen and enzymes are present throughout
fresh food tissues.
Proper canning practices include:
• carefully selecting and washing fresh food,
• peeling some fresh foods,
• hot packing many foods,
• adding acids (lemon juice or vinegar) to some foods,
• using acceptable jars and self-sealing lids,
• processing jars in a boiling-water or pressure canner for the correct period of time.
Collectively, these practices remove oxygen; destroy enzymes; prevent the growth of undesir-
able bacteria, yeasts, and molds; and help form a high vacuum in jars. Good vacuums form
tight seals which keep liquid in and air and microorganisms out.
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Ensuring safe canned foods
Growth of the bacterium Clostridium botulinum in canned food may cause botulism—a deadly
form of food poisoning. These bacteria exist either as spores or as vegetative cells. The spores,
which are comparable to plant seeds, can survive harmlessly in soil and water for many years.
When ideal conditions exist for growth, the spores produce vegetative cells which multiply
rapidly and may produce a deadly toxin within 3 to 4 days of growth in an environment
consisting of:
• a moist, low-acid food
• a temperature between 40° and 120°F
• less than 2 percent oxygen.
Botulinum spores are on most fresh food surfaces. Because they grow only in the absence of
air, they are harmless on fresh foods.
Most bacteria, yeasts, and molds are difcult to remove from food surfaces. Washing fresh
food reduces their numbers only slightly. Peeling root crops, underground stem crops, and
tomatoes reduces their numbers greatly. Blanching also helps, but the vital controls are the
method of canning and making sure the recommended research-based process times, found
in these guides, are used.
The processing times in these guides ensure destruction of the largest expected number of
heat-resistant microorganisms in home-canned foods. Properly sterilized canned food will be
free of spoilage if lids seal and jars are stored below 95°F. Storing jars at 50° to 70°F
enhances retention of quality.
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Food acidity and processing methods
Whether food should be processed in a pressure canner or boiling-water canner to control
botulinum bacteria depends on the acidity of the food. Acidity may be natural, as in most
fruits, or added, as in pickled food. Low-acid canned foods are not acidic enough to prevent
the growth of these bacteria. Acid foods contain enough acid to block their growth, or
destroy them more rapidly when heated. The term “pH” is a measure of acidity; the lower its
value, the more acid the food. The acidity level in foods can be increased by adding lemon
juice, citric acid, or vinegar.
Low-acid foods have pH values higher than 4.6. They include red meats, seafood, poultry,
milk, and all fresh vegetables except for most tomatoes. Most mixtures of low-acid and acid
foods also have pH values above 4.6 unless their recipes include enough lemon juice, citric
acid, or vinegar to make them acid foods. Acid foods have a pH of 4.6 or lower. They include
fruits, pickles, sauerkraut, jams, jellies, marmalades, and fruit butters.
Although tomatoes usually are considered an acid food, some are now known to have pH
values slightly above 4.6. Figs also have pH values slightly above 4.6. Therefore, if they are to
be canned as acid foods, these products must be acidied to a pH of 4.6 or lower with lemon
juice or citric acid. Properly acidied tomatoes and gs are acid foods and can be safely
processed in a boiling-water canner.
Botulinum spores are very hard to destroy at boiling-water temperatures; the higher the can-
ner temperature, the more easily they are destroyed. Therefore, all low-acid foods should be
sterilized at temperatures of 240° to 250°F, attainable with pressure canners operated at 10
to 15 PSIG. PSIG means pounds per square inch of pressure as measured by gauge. The more
familiar “PSI” designation is used hereafter in this publication. At temperatures of 240° to
250°F, the time needed to destroy bacteria in low-acid canned food ranges from 20 to 100
minutes. The exact time depends on the kind of food being canned, the way it is packed into
jars, and the size of jars. The time needed to safely process low-acid foods in a boiling-water
canner ranges from 7 to 11 hours; the time needed to process acid foods in boiling water
varies from 5 to 85 minutes.
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Process adjustments at high altitudes
Using the process time for canning food at sea level may result in spoilage if you live at alti-
tudes of 1,000 feet or more. Water boils at lower temperatures as altitude increases. Lower
boiling temperatures are less effective for killing bacteria. Increasing the process time or
canner pressure compensates for lower boiling temperatures. Therefore, when you use the
guides, select the proper processing time or canner pressure for the altitude where you live.
If you do not know the altitude, contact your local county Extension agent. An alternative
source of information would be the local district conservationist with the Soil Conservation
Service.
Equipment and methods not recommended
Open-kettle canning and the processing of freshly lled jars in conventional ovens, microwave
ovens, and dishwashers are not recommended, because these practices do not prevent all
risks of spoilage. Steam canners are not recommended because processing times for use with
current models have not been adequately researched. Because steam canners do not heat
foods in the same manner as boiling-water canners, their use with boiling-water process times
may result in spoilage. It is not recommended that pressure processes in excess of 15 PSI be
applied when using new pressure canning equipment. So-called canning powders are useless
as preservatives and do not replace the need for proper heat processing. Jars with wire bails
and glass caps make attractive antiques or storage containers for dry food ingredients but are
not recommended for use in canning. One-piece zinc porcelain-lined caps are also no longer
recommended. Both glass and zinc caps use at rubber rings for sealing jars, but too often
fail to seal properly.
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Ensuring high-quality canned foods
Begin with good-quality fresh foods suitable for canning. Quality varies among varieties of
fruits and vegetables. Many county Extension ofces can recommend varieties best suited
for canning. Examine food carefully for freshness and wholesomeness. Discard diseased and
moldy food. Trim small diseased lesions or spots from food.
Can fruits and vegetables picked from your garden or purchased from nearby producers when
the products are at their peak of quality-within 6 to 12 hours after harvest for most vegeta-
bles. For best quality, apricots, nectarines, peaches, pears, and plums should be ripened 1
or more days between harvest and canning. If you must delay the canning of other fresh
produce, keep it in a shady, cool place.
Fresh home-slaughtered red meats and poultry should be chilled and canned without delay.
Do not can meat from sickly or diseased animals. Ice sh and seafoods after harvest, eviscer-
ate immediately, and can them within 2 days.
Maintaining color and avor in canned food
To maintain good natural color and avor in stored canned food, you must:
• Remove oxygen from food tissues and jars,
• Quickly destroy the food enzymes,
• Obtain high jar vacuums and airtight jar seals.
Follow these guidelines to ensure that your canned foods retain optimum colors and avors
during processing and storage:
• Use only high-quality foods which are at the proper maturity and are free of diseases
and bruises.
• Use the hot-pack method, especially with acid foods to be processed in boiling water.
• Don’t unnecessarily expose prepared foods to air. Can them as soon as possible.
• While preparing a canner load of jars, keep peeled, halved, quartered, sliced, or diced
apples, apricots, nectarines, peaches, and pears in a solution of 3 grams (3,000
milligrams) ascorbic acid to 1 gallon of cold water. This procedure is also useful in
maintaining the natural color of mushrooms and potatoes, and for preventing
stem-end discoloration in cherries and grapes. You can get ascorbic acid in several forms:
Pure powdered form—seasonally available among canners’ supplies in supermarkets.
One level teaspoon of pure powder weighs about 3 grams. Use 1 teaspoon per gallon
of water as a treatment solution.
Vitamin C tablets—economical and available year-round in many stores. Buy 500-
milligram tablets; crush and dissolve six tablets per gallon of water as a treatment
solution.
Commercially prepared mixes of ascorbic and citric acid—seasonally available among can-
ners’ supplies in supermarkets. Sometimes citric acid powder is sold in supermarkets,
but it is less effective in controlling discoloration. If you choose to use these products,
follow the manufacturer’s directions.
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• Fill hot foods into jars and adjust headspace as specied in recipes.
• Tighten screw bands securely, but if you are especially strong, not as tightly as possible.
• Process and cool jars.
• Store the jars in a relatively cool, dark place, preferably between 50° and 70°F.
• Can no more food than you will use within a year.
Advantages of hot-packing
Many fresh foods contain from 10 percent to more than 30 percent air. How long canned
food retains high quality depends on how much air is removed from food before jars are
sealed.
Raw-packing is the practice of lling jars tightly with freshly prepared, but unheated food.
Such foods, especially fruit, will oat in the jars. The entrapped air in and around the food
may cause discoloration within 2 to 3 months of storage. Raw-packing is more suitable for
vegetables processed in a pressure canner.
Hot-packing is the practice of heating freshly prepared food to boiling, simmering it 2 to 5
minutes, and promptly lling jars loosely with the boiled food. Whether food has been hot-
packed or raw-packed, the juice, syrup, or water to be added to the foods should also be
heated to boiling before adding it to the jars. This practice helps to remove air from food
tissues, shrinks food, helps keep the food from oating in the jars, increases vacuum in sealed
jars, and improves shelf life. Preshrinking food permits lling more food into each jar.
Hot-packing is the best way to remove air and is the preferred pack style for foods processed
in a boiling-water canner. At rst, the color of hot-packed foods may appear no better than
that of raw-packed foods, but within a short storage period, both color and avor of hot-
packed foods will be superior.
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Controlling headspace
The unlled space above the food in a jar and below its lid is termed headspace. Directions
for canning specify leaving 1/4-inch for jams and jellies, 1/2-inch for fruits and tomatoes to
be processed in boiling water, and from 1- to 1-1/4-inches in low acid foods to be processed
in a pressure canner. This space is needed for expansion of food as jars are processed, and for
forming vacuums in cooled jars. The extent of expansion is determined by the air content in
the food and by the processing temperature. Air expands greatly when heated to high tem-
peratures; the higher the temperature, the greater the expansion. Foods expand less than air
when heated.
Jars and lids
Food may be canned in glass jars or metal containers. Metal containers can be used only
once. They require special sealing equipment and are much more costly than jars.
Regular and wide-mouth Mason-type, threaded, home-canning jars with self-sealing lids are
the best choice. They are available in 1/2 pint, pint, 1-1/2 pint, quart, and 1/2 gallon sizes.
The standard jar mouth opening is about 2-3/8 inches. Wide-mouth jars have openings of
about 3 inches, making them more easily lled and emptied. Half-gallon jars may be used for
canning very acid juices. Regular-mouth decorator jelly jars are available in 8 and 12 ounce
sizes. With careful use and handling, Mason jars may be reused many times, requiring only
new lids each time. When jars and lids are used properly, jar seals and vacuums are excellent
and jar breakage is rare.
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Most commercial pint- and quart-size mayonnaise or salad dressing jars may be used with
new two-piece lids for canning acid foods. However, you should expect more seal failures and
jar breakage. These jars have a narrower sealing surface and are tempered less than Mason
jars, and may be weakened by repeated contact with metal spoons or knives used in dispens-
ing mayonnaise or salad dressing. Seemingly insignicant scratches in glass may cause crack-
ing and breakage while processing jars in a canner. Mayonnaise-type jars are not recommend-
ed for use with foods to be processed in a pressure canner because of excessive jar breakage.
Other commercial jars with mouths that cannot be sealed with two-piece canning lids are not
recommended for use in canning any food at home.
Jar cleaning and preparation
Before every use, wash empty jars in hot water with detergent and rinse well by hand, or wash
in a dishwasher. Unrinsed detergent residues may cause unnatural avors and colors. Jars
should be kept hot until ready to ll with food. Submerge the clean empty jars in enough
water to cover them in a large stockpot or boiling water canner. Bring the water to a simmer
(180°F) and keep the jars in the simmering water until it is time to ll them with food. A
dishwasher may be used for preheating jars if they are washed and dried on a complete regu-
lar cycle. Keep the jars in the closed dishwasher until needed for lling.
These washing and preheating methods do not sterilize jars. Some used jars may have a
white lm on the exterior surface caused by mineral deposits. This scale or hard-water lm on
jars is easily removed by soaking jars several hours in a solution containing 1 cup of vinegar
(5 percent acidity) per gallon of water prior to washing and preheating the jars.
Sterilization of empty jars
All jams, jellies, and pickled products processed less than 10 minutes should be lled into
sterile empty jars. To sterilize empty jars after washing in detergent and rinsing thoroughly,
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submerge them, right side up, in a boiling-water canner with the rack in the bottom. Fill the
canner with enough warm water so it is 1 inch above the tops of the jars. Bring the water to a
boil, and boil 10 minutes at altitudes of less than 1,000 ft. At higher elevations, boil 1 addi-
tional minute for each additional 1,000 ft elevation. Reduce the heat under the canner, and
keep the jars in the hot water until it is time to ll them. Remove and drain hot sterilized jars
one at a time, saving the hot water in the canner for processing lled jars. Fill the sterilized
jars with food, add lids, and tighten screw bands.
Empty jars used for vegetables, meats, and fruits to be processed in a pressure canner need
not be presterilized. It is also unnecessary to presterilize jars for fruits, tomatoes, and pickled
or fermented foods that will be processed 10 minutes or longer in a boiling-water canner.
Lid selection, preparation, and use
The common self-sealing lid consists of a at metal lid held in place by a metal screw band
during processing. The at lid is crimped around its bottom edge to form a trough, which is
lled with a colored gasket compound. When jars are processed, the lid gasket softens and
ows slightly to cover the jar-sealing surface, yet allows air to escape from the jar. The gasket
then forms an airtight seal as the jar cools. Gaskets in unused lids work well for at least 5
years from date of manufacture. The gasket compound in older unused lids may fail to seal
on jars.
Buy only the quantity of lids you will use in a year. To ensure a good seal, carefully follow the
manufacturer’s directions in preparing lids for use. Examine all metal lids carefully. Do not
use old, dented, or deformed lids, or lids with gaps or other defects in the sealing gasket.
When directions say to ll jars and adjust lids, use the following procedures: After lling
jars with food and adding covering liquid, release air bubbles by inserting a at plastic (not
metal) spatula between the food and the jar. Slowly turn the jar and move the spatula up and
down to allow air bubbles to escape. (It is not necessary to release air bubbles when lling
jams, jellies or all liquid foods such as juices.) Adjust the headspace and then clean the jar rim
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(sealing surface) with a dampened paper towel. Place the preheated lid, gasket down, onto
the cleaned jar-sealing surface. Uncleaned jar-sealing surfaces may cause seal failures. Then t
the metal screw band over the at lid. Follow the manufacturer’s guidelines enclosed with or
on the box for tightening the jar lids properly.
Do not retighten lids after processing jars. As jars cool, the contents in the jar contract, pull-
ing the self-sealing lid rmly against the jar to form a high vacuum.
• If rings are too loose, liquid may escape from jars during processing, and seals may fail.
• If rings are too tight, air cannot vent during processing, and food will discolor during
storage. Over tightening also may cause lids to buckle and jars to break, especially with
raw-packed, pressure-processed food.
Screw bands are not needed on stored jars. They can be removed easily after jars are cooled.
When removed, washed, dried, and stored in a dry area, screw bands may be used many times.
If left on stored jars, they become difcult to remove, often rust, and may not work properly
again.
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Recommended canners
Equipment for heat-processing home-canned food is of two main types—boiling water can-
ners and pressure canners. Most are designed to hold seven quart jars or eight to nine pints.
Small pressure canners hold four-quart jars; some large pressure canners hold 18 pint jars in
two layers, but hold only seven quart jars. Pressure saucepans with smaller volume capaci-
ties are not recommended for use in canning. Small capacity pressure canners are treated in
a similar manner as standard larger canners, and should be vented using the typical venting
procedures.
Low-acid foods must be processed in a pressure canner to be free of botulism risks. Although
pressure canners may also be used for processing acid foods, boiling water canners are rec-
ommended for this purpose because they are faster. A pressure canner would require from 55
to 100 minutes to process a load of jars; while the total time for processing most acid foods
in boiling water varies from 25 to 60 minutes. A boiling-water canner loaded with lled jars
requires about 20 to 30 minutes of heating before its water begins to boil. A loaded pressure
canner requires about 12 to 15 minutes of heating before it begins to vent; another 10 minutes
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to vent the canner; another 5 minutes to pressurize the canner; another 8 to 10 minutes to
process the acid food; and, nally, another 20 to 60 minutes to cool the canner before remov-
ing jars.
Boiling-water canners
These canners are made of aluminum or porcelain-covered steel. They have removable perfo-
rated racks and tted lids. The canner must be deep enough so that at least 1 inch of briskly
boiling water will be over the tops of jars during processing. Some boiling-water canners do
not have at bottoms. A at bottom must be used on an electric range. Either a at or ridged
bottom can be used on a gas burner. To ensure uniform processing of all jars with an electric
range, the canner should be no more than 4 inches wider in diameter than the element on
which it is heated.
Using boiling-water canners
Follow these steps for successful boiling-water canning:
1. Before you start preparing your food, ll the canner halfway with clean water. This is
approximately the level needed for a canner load of pint jars. For other sizes and
numbers of jars, the amount of water in the canner will need to be adjusted so it will
be 1 to 2 inches over the top of the lled jars.
2. Preheat water to 140°F for raw-packed foods and to 180°F for hot-packed foods.
Food preparation can begin while this water is preheating.
3. Load lled jars, tted with lids, into the canner rack and use the handles to lower the
rack into the water; or ll the canner with the rack in the bottom, one jar at a time,
using a jar lifter. When using a jar lifter, make sure it is securely positioned below the
neck of the jar (below the screw band of the lid). Keep the jar upright at all times.
Tilting the jar could cause food to spill into the sealing area of the lid.
4. Add more boiling water, if needed, so the water level is at least 1 inch above jar tops.
For process times over 30 minutes, the water level should be at least 2 inches above the
tops of the jars.
5. Turn heat to its highest position, cover the canner with its lid, and heat until the water
in the canner boils vigorously.
6. Set a timer for the total minutes required for processing the food.
7. Keep the canner covered and maintain a boil throughout the process schedule. The
heat setting may be lowered a little as long as a complete boil is maintained for the
entire process time. If the water stops boiling at any time during the process, bring the
water back to a vigorous boil and begin the timing of the process over, from the
beginning.
8. Add more boiling water, if needed, to keep the water level above the jars.
9. When jars have been boiled for the recommended time, turn off the heat and remove
the canner lid. Wait 5 minutes before removing jars.
10. Using a jar lifter, remove the jars and place them on a towel, leaving at least 1-inch
spaces between the jars during cooling. Let jars sit undisturbed to cool at room
temperature for 12 to 24 hours.
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Pressure canners
Pressure canners for use in the home have been extensively redesigned in recent years. Models
made before the 1970’s were heavy-walled kettles with clamp-on or turn-on lids. They were
tted with a dial gauge, a vent port in the form of a petcock or counterweight, and a safety
fuse. Modern pressure canners are lightweight, thin walled kettles; most have turn-on lids.
They have a jar rack, gasket, dial or weighted gauge, an automatic vent/cover lock, a vent port
(steam vent) to be closed with a counterweight or weighted gauge, and a safety fuse.
Pressure does not destroy microorganisms, but high temperatures applied for an adequate
period of time do kill microorganisms. The success of destroying all microorganisms capable
of growing in canned food is based on the temperature obtained in pure steam, free of air, at
sea level. At sea level, a canner operated at a gauge pressure of 10.5 lbs provides an internal
temperature of 240°F.
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Two serious errors in temperatures obtained in pressure canners occur because:
1. Internal canner temperatures are lower at higher altitudes. To correct this error,
canners must be operated at the increased pressures specied in this publication for
appropriate altitude ranges.
2. Air trapped in a canner lowers the temperature obtained at 5, 10, or 15 pounds
of pressure and results in under processing. The highest volume of air trapped in a
canner occurs in processing raw-packed foods in dial-gauge canners. These canners
do not vent air during processing. To be safe, all types of pressure canners must be
vented 10 minutes before they are pressurized.
To vent a canner, leave the vent port uncovered on newer models or manually open petcocks
on some older models. Heating the lled canner with its lid locked into place boils water and
generates steam that escapes through the petcock or vent port. When steam rst escapes,
set a timer for 10 minutes. After venting 10 minutes, close the petcock or place the counter-
weight or weighted gauge over the vent port to pressurize the canner.
Weighted-gauge models exhaust tiny amounts of air and steam each time their gauge rocks
or jiggles during processing. They control pressure precisely and need neither watching during
processing nor checking for accuracy. The sound of the weight rocking or jiggling indicates
that the canner is maintaining the recommended pressure. The single disadvantage of weight-
ed-gauge canners is that they cannot correct precisely for higher altitudes. At altitudes above
1,000 feet, they must be operated at canner pressures of 10 instead of 5, or 15 instead of 10,
PSI.
Check dial gauges for accuracy before use each year. Gauges that read high cause under-pro-
cessing and may result in unsafe food. Low readings cause over-processing. Pressure adjust-
ments can be made if the gauge reads up to 2 pounds high or low. Replace gauges that dif-
fer by more than 2 pounds. Every pound of pressure is very important to the temperature
needed inside the canner for producing safe food, so accurate gauges and adjustments are
essential when a gauge reads higher than it should. If a gauge is reading lower than it should,
adjustments may be made to avoid overprocessing, but are not essential to safety. Gauges
may be checked at many county Cooperative Extension ofces or contact the pressure canner
manufacturer for other options.
Handle canner lid gaskets carefully and clean them according to the manufacturer’s direc-
tions. Nicked or dried gaskets will allow steam leaks during pressurization of canners. Keep
gaskets clean between uses. Gaskets on older model canners may require a light coat of vege-
table oil once per year. Gaskets on newer model canners are pre-lubricated and do not benet
from oiling. Check your canner’s instructions if there is doubt that the particular gasket you
use has been pre-lubricated.
Lid safety fuses are thin metal inserts or rubber plugs designed to relieve excessive pressure
from the canner. Do not pick at or scratch fuses while cleaning lids. Use only canners that
have the Underwriter’s Laboratory (UL) approval to ensure their safety.
Replacement gauges and other parts for canners are often available at stores offering
canning equipment or from canner manufacturers. When ordering parts, give your canner
model number and describe the parts needed.
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Using pressure canners
Follow these steps for successful pressure canning:
1. Put 2 to 3 inches of hot water in the canner. Some specic products in this Guide
require that you start with even more water in the canner. Always follow the directions
with USDA processes for specic foods if they require more water added to the
canner. Place lled jars on the rack, using a jar lifter. When using a jar lifter, make sure
it is securely positioned below the neck of the jar (below the screw band of the lid).
Keep the jar upright at all times. Tilting the jar could cause food to spill into the
sealing are of the lid. Fasten canner lid securely.
2. Leave weight off vent port or open petcock. Heat at the highest setting until steam
ows freely from the open petcock or vent port.
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3. While maintaining the high heat setting, let the steam ow (exhaust) continuously for
10 minutes, and then place the weight on the vent port or close the petcock. The
canner will pressurize during the next 3 to 5 minutes.
4. Start timing the process when the pressure reading on the dial gauge indicates that the
recommended pressure has been reached, or when the weighted gauge begins to jiggle
or rock as the canner manufacturer describes.
5. Regulate heat under the canner to maintain a steady pressure at or slightly above the
correct gauge pressure. Quick and large pressure variations during processing may
cause unnecessary liquid losses from jars. Follow the canner manufacturer’s directions
for how a weighted gauge should indicate it is maintaining the desired pressure.
IMPORTANT: If at any time pressure goes below the recommended amount, bring the
canner back to pressure and begin the timing of the process over, from the beginning
(using the total original process time). This is important for the safety of the food.
6. When the timed process is completed, turn off the heat, remove the canner from
heat if possible, and let the canner depressurize. Do not force-cool the canner. Forced
cooling may result in unsafe food or food spoilage. Cooling the canner with cold
running water or opening the vent port before the canner is fully depressurized will
cause loss of liquid from jars and seal failures. Force-cooling may also warp the canner
lid of older model canners, causing steam leaks. Depressurization of older models
without dial gauges should be timed. Standard-size heavy-walled canners require about
30 minutes when loaded with pints and 45 minutes with quarts. Newer thin-walled
canners cool more rapidly and are equipped with vent locks. These canners are
depressurized when their vent lock piston drops to a normal position.
7. After the canner is depressurized, remove the weight from the vent port or open the
petcock. Wait 10 minutes, unfasten the lid, and remove it carefully. Lift the lid away
from you so that the steam does not burn your face.
8. Remove jars with a jar lifter, and place them on a towel, leaving at least 1-inch spaces
between the jars during cooling. Let jars sit undisturbed to cool at room temperature
for 12 to 24 hours.
Selecting the correct processing time
When canning in boiling water, more processing time is needed for most raw-packed foods
and for quart jars than is needed for hot-packed foods and pint jars.
To destroy microorganisms in acid foods processed in a boiling-water canner, you must:
• Process jars for the correct number of minutes in boiling water.
• Cool the jars at room temperature.
The food may spoil if you fail to add process time for lower boiling-water temperatures at
altitudes above 1,000 feet, process for fewer minutes than specied, or cool jars in cold water.
Principles of Home Canning
1
1-
To destroy microorganisms in low-acid foods processed with a pressure canner, you must:
• Process the jars using the correct time and pressure specied for your altitude.
• Allow canner to cool at room temperature until it is completely depressurized.
The food may spoil if you fail to select the proper process times for specic altitudes, fail to
exhaust canners properly, process at lower pressure than specied, process for fewer minutes
than specied, or cool the canner with water.
Using tables for determining proper process times
This set of guides includes processing times with altitude adjustments for each product. Pro-
cess times for 1/2-pint and pint jars are the same, as are times for 1-1/2 pint and quart jars.
For some products, you have a choice of processing at 5, 10, or 15 PSI. In these cases, choose
the canner pressure you wish to use and match it with your pack style (raw or hot) and jar
size to nd the correct process time. The following examples show how to select the proper
process for each type of canner. Process times are given in separate tables for sterilizing jars in
boiling-water, dial-gauge, and weighted-gauge pressure canners.
Example A: Boiling-water Canner
Suppose you are canning peaches as a hot-pack in quarts at 2,500 ft above sea level, using
a boiling-water canner. First, select the process table for boiling-water canner. The example for
peaches is given in Table for Example A below. From that table, select the process time given
for (1) the style of pack (hot), (2) the jar size (quarts), and (3) the altitude where you live
(2,500 ft). You should have selected a process time of 30 minutes.
(Ken�–�These�are�Guide�1�Process�Tables,�from�original�USDA�p.�1-25�and�1-33,�sized�as
they�were�on�the�page,�at�about�5-3/8�inch�wide.��I�sized�and�spaced�the�text�in�header
row�purposefully�a�little�differently�than�the�original)
Table�for�Example�A
Recommended�process�time�for�Peaches�in�a�boiling-water�canner
Process�Time�at�Altitudes�of
Style
of�Pack
Jar
Size
0–
1,000�ft
1,001–
3,000�ft
3,001–
6,000�ft
Above
6,000�ft
Hot Pints 20�min 25�min 30�min 35�min
Quarts 25 30 35 40
Raw Pints 25 30 35 40
Quarts 30 35 40 45
Table�for�Example�B
Recommended�process�time�for�Peaches�in�a�dial-gauge�pressure�canner
Canner�Pressure�(PSI)�at�Altitudes�of
Style
of�Pack
Jar
Size
Process
Time
0–
2,000�ft
2,001–
4,000�ft
4,001–
6,000�ft
6,001–
8,000�ft
Hot
and
Raw
Pints
or
Quarts
10�min 6�lb 7�lb 8�lb 9�lb
Table�for�Example�C
Recommended�process�time�for�Peaches�in�a�weighted-gauge�pressure�canner
Canner�Pressure�(PSI)�at�Altitudes�of
Style
of�Pack
Jar
Size
Process
Time
0–
1,000�ft
Above
1,000�ft
Hot
and
Raw
Pints
or
Quarts
10�min 5�lb 10�lb
Recommended�process�time�for�fruit-based�baby�foods�in�a�boiling-water�canner
Process�Time�at�Altitudes�of
Style
of�Pack
Jar
Size
0–
1,000�ft
1,001–
6,000�ft
Above
6,000�ft
Hot Pints 20�min 25�min 30�min
1-
(Ken�–�These�are�Guide�1�Process�Tables,�from�original�USDA�p.�1-25�and�1-33,�sized�as
they�were�on�the�page,�at�about�5-3/8�inch�wide.��I�sized�and�spaced�the�text�in�header
row�purposefully�a�little�differently�than�the�original)
Table�for�Example�A
Recommended�process�time�for�Peaches�in�a�boiling-water�canner
Process�Time�at�Altitudes�of
Style
of�Pack
Jar
Size
0–
1,000�ft
1,001–
3,000�ft
3,001–
6,000�ft
Above
6,000�ft
Hot Pints 20�min 25�min 30�min 35�min
Quarts 25 30 35 40
Raw Pints 25 30 35 40
Quarts 30 35 40 45
Table�for�Example�B
Recommended�process�time�for�Peaches�in�a�dial-gauge�pressure�canner
Canner�Pressure�(PSI)�at�Altitudes�of
Style
of�Pack
Jar
Size
Process
Time
0–
2,000�ft
2,001–
4,000�ft
4,001–
6,000�ft
6,001–
8,000�ft
Hot
and
Raw
Pints
or
Quarts
10�min 6�lb 7�lb 8�lb 9�lb
Table�for�Example�C
Recommended�process�time�for�Peaches�in�a�weighted-gauge�pressure�canner
Canner�Pressure�(PSI)�at�Altitudes�of
Style
of�Pack
Jar
Size
Process
Time
0–
1,000�ft
Above
1,000�ft
Hot
and
Raw
Pints
or
Quarts
10�min 5�lb 10�lb
Recommended�process�time�for�fruit-based�baby�foods�in�a�boiling-water�canner
Process�Time�at�Altitudes�of
Style
of�Pack
Jar
Size
0–
1,000�ft
1,001–
6,000�ft
Above
6,000�ft
Hot Pints 20�min 25�min 30�min
Example B: Dial-gauge Pressure Canner
Suppose you are canning peaches as a hot-pack in quarts at 2,500 ft above sea level, using a
dial-gauge pressure canner. First, select the process table for dial-gauge pressure canner. The ex-
ample for peaches is given in Table for Example B below. From that table, select the process
pressure (PSI) given for (1) the style of pack (hot), (2) the jar size (quarts), (3) the process
time (10 minutes), (4) the altitude where you live (2,500 ft). You should have selected a pres-
sure of 7 lbs for the 10 minutes process time.
Example C: Weighted-gauge Pressure Canner
Suppose you are canning peaches as a hot-pack in quarts at 2,500 ft above sea level, using a
weighted-gauge pressure canner. First, select the process table for weighted-gauge pressure can-
ner. The example for peaches is given in Table for Example C below. From that table, select
the process pressure (PSI) given for (1) the style of pack (hot), (2) the jar size (quarts), (3)
the process time (10 minutes), and (4) the altitude where you live (2,500 ft). You should have
selected a pressure of 10 lbs for the 10 minutes process time.
(Ken�–�These�are�Guide�1�Process�Tables,�from�original�USDA�p.�1-25�and�1-33,�sized�as
they�were�on�the�page,�at�about�5-3/8�inch�wide.��I�sized�and�spaced�the�text�in�header
row�purposefully�a�little�differently�than�the�original)
Table�for�Example�A
Recommended�process�time�for�Peaches�in�a�boiling-water�canner
Process�Time�at�Altitudes�of
Style
of�Pack
Jar
Size
0–
1,000�ft
1,001–
3,000�ft
3,001–
6,000�ft
Above
6,000�ft
Hot Pints 20�min 25�min 30�min 35�min
Quarts 25 30 35 40
Raw Pints 25 30 35 40
Quarts 30 35 40 45
Table�for�Example�B
Recommended�process�time�for�Peaches�in�a�dial-gauge�pressure�canner
Canner�Pressure�(PSI)�at�Altitudes�of
Style
of�Pack
Jar
Size
Process
Time
0–
2,000�ft
2,001–
4,000�ft
4,001–
6,000�ft
6,001–
8,000�ft
Hot
and
Raw
Pints
or
Quarts
10�min 6�lb 7�lb 8�lb 9�lb
Table�for�Example�C
Recommended�process�time�for�Peaches�in�a�weighted-gauge�pressure�canner
Canner�Pressure�(PSI)�at�Altitudes�of
Style
of�Pack
Jar
Size
Process
Time
0–
1,000�ft
Above
1,000�ft
Hot
and
Raw
Pints
or
Quarts
10�min 5�lb 10�lb
Recommended�process�time�for�fruit-based�baby�foods�in�a�boiling-water�canner
Process�Time�at�Altitudes�of
Style
of�Pack
Jar
Size
0–
1,000�ft
1,001–
6,000�ft
Above
6,000�ft
Hot Pints 20�min 25�min 30�min
Principles of Home Canning
1
1-
Cooling jars
When you remove hot jars from a canner, do not retighten their jar lids. Retightening of hot
lids may cut through the gasket and cause seal failures. Cool the jars at room temperature for
12 to 24 hours. Jars may be cooled on racks or towels to minimize heat damage to counters.
The food level and liquid volume of raw-packed jars will be noticeably lower after cooling. Air
is exhausted during processing and food shrinks. If a jar loses excessive liquid during process-
ing, do not open it to add more liquid. Check for sealed lids as described below.
Testing jar seals
After cooling jars for 12 to 24 hours, remove the screw bands and test seals with one of the
following options:
Option 1. Press the middle of the lid with a nger or thumb. If the lid springs up when you
release your nger, the lid is unsealed.
Option 2. Tap the lid with the bottom of a teaspoon. If it makes a dull sound, the lid is not
sealed. If food is in contact with the underside of the lid, it will also cause a dull
sound. If the jar is sealed correctly, it will make a ringing, high-pitched sound.
Option 3. Hold the jar at eye level and look across the lid. The lid should be concave
(curved down slightly in the center). If center of the lid is either at or bulging, it
may not be sealed.
1-
Reprocessing unsealed jars
If a lid fails to seal on a jar, remove the lid and check the jar-sealing surface for tiny nicks. If
necessary, change the jar, add a new, properly prepared lid, and reprocess within 24 hours
using the same processing time. Headspace in unsealed jars may be adjusted to 1-1/2 inches
and jars could be frozen instead of reprocessed. Foods in single unsealed jars could be stored
in the refrigerator and consumed within several days.
Storing canned foods
If lids are tightly vacuum sealed on cooled jars, remove screw bands, wash the lid and jar
to remove food residue; then rinse and dry jars. Label and date the jars and store them in a
clean, cool, dark, dry place. Do not store jars above 95°F or near hot pipes, a range, a fur-
nace, under a sink, in an uninsulated attic, or in direct sunlight. Under these conditions, food
will lose quality in a few weeks or months and may spoil. Dampness may corrode metal lids,
break seals, and allow recontamination and spoilage.
Accidental freezing of canned foods will not cause spoilage unless jars become unsealed and
recontaminated. However, freezing and thawing may soften food. If jars must be stored where
they may freeze, wrap them in newspapers, place them in heavy cartons, and cover with more
newspapers and blankets.
Identifying and handling spoiled canned food
Do not taste food from a jar with an unsealed lid or food that shows signs of spoilage. You
can more easily detect some types of spoilage in jars stored without screw bands. Growth of
spoilage bacteria and yeast produces gas which pressurizes the food, swells lids, and breaks
jar seals. As each stored jar is selected for use, examine its lid for tightness and vacuum. Lids
with concave centers have good seals.
Next, while holding the jar upright at eye level, rotate the jar and examine its outside surface
for streaks of dried food originating at the top of the jar. Look at the contents for rising air
bubbles and unnatural color.
Principles of Home Canning
1
1-
While opening the jar, smell for unnatural odors and look for spurting liquid and cotton-like
mold growth (white, blue, black, or green) on the top food surface and underside of lid.
Spoiled low-acid foods, including tomatoes, may exhibit different kinds of spoilage evidence
or very little evidence. Therefore, all suspect containers of spoiled low-acid foods, including
tomatoes, should be treated as having produced botulinum toxin and handled carefully in
one of two ways:
• If the suspect glass jars or swollen metal cans are still sealed, place them in a heavy
garbage bag. Close and place the bag in a regular trash container or dispose in a nearby
landll.
• If the suspect glass jars or cans are unsealed, open, or leaking, they should be detoxied
before disposal.
Detoxication process: Wear disposable rubber or heavy plastic gloves. Carefully place the
suspect containers and lids on their sides in an 8-quart volume or larger stock pot, pan, or
boiling-water canner. Wash your hands with gloves thoroughly. Carefully add water to the
pot and avoid splashing the water. The water should completely cover the containers with a
minimum of a 1-inch level above the containers. Place a lid on the pot and heat the water to
boiling. Boil 30 minutes to ensure detoxifying the food and all container components. Cool
and discard the containers, their lids, and food in the trash or dispose in a nearby landll.
Cleaning up the area: Contact with botulinum toxin can be fatal whether it is ingested or
enters through the skin. Take care to avoid contact with suspect foods or liquids. Wear rub-
ber or heavy plastic gloves when handling suspect foods or cleaning up contaminated work
surfaces and equipment. A fresh solution of 1 part unscented liquid household chlorine
bleach (5 to 6% sodium hypochlorite) to 5 parts clean water should be used to treat work
surfaces, equipment, or other items, including can openers and clothing, that may have come
in contact with suspect foods or liquids. Spray or wet contaminated surfaces with the bleach
solution and let stand for 30 minutes. Wearing gloves, wipe up treated spills with paper tow-
els being careful to minimize the spread of contamination. Dispose of these paper towels by
placing them in a plastic bag before putting them in the trash. Next, apply the bleach solu-
tion to all surfaces and equipment again, and let stand for 30 minutes and rinse. As a last
step, thoroughly wash all detoxied counters, containers, equipment, clothing, etc. Discard
gloves when cleaning process is complete. (Note: Bleach is an irritant itself and should not be
inhaled or allowed to come in contact with the skin.)
Preparing pickled and fermented foods
The many varieties of pickled and fermented foods are classied by ingredients and method
of preparation.
Regular dill pickles and sauerkraut are fermented and cured for about 3 weeks. Refrigerator dills
are fermented for about 1 week. During curing, colors and avors change and acidity increases.
Fresh-pack or quick-process pickles are not fermented; some are brined several hours or over-
night, then drained and covered with vinegar and seasonings. Fruit pickles usually are prepared
by heating fruit in a seasoned syrup acidied with either lemon juice or vinegar. Relishes are
made from chopped fruits and vegetables that are cooked with seasonings and vinegar.
1-
Be sure to remove and discard a 1/16-inch slice from the blossom end of fresh cucumbers.
Blossoms may contain an enzyme which causes excessive softening of pickles.
Caution: The level of acidity in a pickled product is as important to its safety as it is to taste
and texture.
• Do not alter vinegar, food, or water proportions in a recipe or use a vinegar with
unknown acidity.
• Use only recipes with tested proportions of ingredients.
• There must be a minimum, uniform level of acid throughout the mixed product to
prevent the growth of botulinum bacteria.
Ingredients
Select fresh, rm fruits or vegetables free of spoilage. Measure or weigh amounts carefully,
because the proportion of fresh food to other ingredients will affect avor and, in many in-
stances, safety.
Use canning or pickling salt. Noncaking material added to other salts may make the brine
cloudy. Since ake salt varies in density, it is not recommended for making pickled and fer-
mented foods. White granulated and brown sugars are most often used. Corn syrup and
honey, unless called for in reliable recipes, may produce undesirable avors. White distilled
and cider vinegars of 5 percent acidity (50 grain) are recommended. White vinegar is usually
preferred when light color is desirable, as is the case with fruits and cauliower.
Pickles with reduced salt content
Recipes for pickles with reduced sodium content are provided in Guide 6.
In the making of fresh-pack pickles, cucumbers are acidied quickly with vinegar. Use only
tested recipes formulated to produce the proper acidity. While these pickles may be prepared
safely with reduced or no salt, their quality may be noticeably lower. Both texture and avor
may be slightly, but noticeably, different than expected. You may wish to make small quanti-
ties rst to determine if you like them.
However, the salt used in making fermented sauerkraut and brined pickles not only provides
characteristic avor but also is vital to safety and texture. In fermented foods, salt favors the
growth of desirable bacteria while inhibiting the growth of others. Caution: Do not attempt
to make sauerkraut or fermented pickles by cutting back on the salt required.
Firming agents
Alum may be safely used to rm fermented pickles. However, it is unnecessary and is not in-
cluded in the recipes in this publication. Alum does not improve the rmness of quick-process
pickles. The calcium in lime denitely improves pickle rmness. Food-grade lime may be used
as a lime-water solution for soaking fresh cucumbers 12 to 24 hours before pickling them.
Excess lime absorbed by the cucumbers must be removed to make safe pickles. To remove
excess lime, drain the lime-water solution, rinse, and then resoak the cucumbers in fresh water
for 1 hour. Repeat the rinsing and soaking steps two more times. To further improve pickle
Principles of Home Canning
1
1-
rmness, you may process cucumber pickles for 30 minutes in water at 180°F. This process
also prevents spoilage, but the water temperature should not fall below 180°F. Use a candy
or jelly thermometer to check the water temperature.
Preventing spoilage
Pickle products are subject to spoilage from microorganisms, particularly yeasts and molds,
as well as enzymes that may affect avor, color, and texture. Processing the pickles in a boil-
ing-water canner will prevent both of these problems. Standard canning jars and self-sealing
lids are recommended. Processing times and procedures will vary according to food acidity
and the size of food pieces.
Preparing butters, jams, jellies, and marmalades
Sweet spreads are a class of foods with many textures, avors, and colors. They all consist of
fruits preserved mostly by means of sugar and they are thickened or jellied to some extent.
Fruit jelly is a semi-solid mixture of fruit juice and sugar that is clear and rm enough to hold
its shape. Other spreads are made from crushed or ground fruit.
Jam also will hold its shape, but it is less rm than jelly. Jam is made from crushed or chopped
fruits and sugar. Jams made from a mixture of fruits are usually called conserves, especially
when they include citrus fruits, nuts, raisins, or coconut. Preserves are made of small, whole
fruits or uniform-size pieces of fruits in a clear, thick, slightly jellied syrup. Marmalades are
soft fruit jellies with small pieces of fruit or citrus peel evenly suspended in a transparent jelly.
Fruit butters are made from fruit pulp cooked with sugar until thickened to a spreadable con-
sistency.
Ingredients
For proper texture, jellied fruit products require the correct combination of fruit, pectin, acid,
and sugar. The fruit gives each spread its unique avor and color. It also supplies the water to
dissolve the rest of the necessary ingredients and furnishes some or all of the pectin and acid.
Good-quality, avorful fruits make the best jellied products.
Pectins are substances in fruits that form a gel if they are in the right combination with acid
and sugar. All fruits contain some pectin. Apples, crab apples, gooseberries, and some plums
and grapes usually contain enough natural pectin to form a gel. Other fruits, such as straw-
berries, cherries, and blueberries, contain little pectin and must be combined with other fruits
high in pectin or with commercial pectin products to obtain gels. Because fully ripened fruit
has less pectin, one-fourth of the fruit used in making jellies without added pectin should be
underripe.
Caution: Commercially frozen and canned juices may be low in natural pectins and make
soft textured spreads.
The proper level of acidity is critical to gel formation. If there is too little acid, the gel will
never set; if there is too much acid, the gel will lose liquid (weep). For fruits low in acid, add
lemon juice or other acid ingredients as directed. Commercial pectin products contain acids
which help to ensure gelling.
1-0
Sugar serves as a preserving agent, contributes avor, and aids in gelling. Cane and beet
sugar are the usual sources of sugar for jelly or jam. Corn syrup and honey may be used to
replace part of the sugar in recipes, but too much will mask the fruit avor and alter the gel
structure. Use tested recipes for replacing sugar with honey and corn syrup. Do not try to
reduce the amount of sugar in traditional recipes. Too little sugar prevents gelling and may
allow yeasts and molds to grow.
Jams and jellies with reduced sugar
Jellies and jams that contain modied pectin, gelatin, or gums may be made with noncaloric
sweeteners. Jams with less sugar than usual also may be made with concentrated fruit pulp,
which contains less liquid and less sugar. See Guide 7 for recipes.
Two types of modied pectin are available for home use. One gels with one-third less sugar.
The other is a low-methoxyl pectin which requires a source of calcium for gelling. To prevent
spoilage, jars of these products may need to be processed longer in a boiling-water canner.
Recipes and processing times provided with each modied pectin product must be followed
carefully. The proportions of acids and fruits should not be altered, as spoilage may result.
Acceptably gelled refrigerator fruit spreads also may be made with gelatin and sugar substi-
tutes. Such products spoil at room temperature, must be refrigerated, and should be eaten
within 1 month.
Preventing spoilage
Even though sugar helps preserve jellies and jams, molds can grow on the surface of these
products. Research now indicates that the mold which people usually scrape off the surface
of jellies may not be as harmless as it seems. Mycotoxins have been found in some jars of jelly
having surface mold growth. Mycotoxins are known to cause cancer in animals; their
effects on humans are still being researched. Because of possible mold contamination,
parafn or wax seals are no longer recommended for any sweet spread, including jellies. To
prevent growth of molds and loss of good avor or color, ll products hot into sterile Mason
jars, leaving 1/4-inch headspace, seal with self-sealing lids, and process 5 minutes in a
boiling-water canner. Correct process time at higher elevations by adding 1 additional
minute per 1,000 ft above sea level. If unsterile jars are used, the lled jars should be pro-
cessed 10 minutes. Use of sterile jars is preferred, especially when fruits are low in pectin,
since the added 5-minute process time may cause weak gels. To sterilize empty jars, see page
1-14.
Methods of making jams and jellies
The two basic methods of making jams and jellies are described in Guide 7. The standard
method, which does not require added pectin, works best with fruits naturally high in pectin.
The other method, which requires the use of commercial liquid or powdered pectin, is much
quicker. The gelling ability of various pectins differs. To make uniformly gelled products,
be sure to add the quantities of commercial pectins to specic fruits as instructed on each
package. Overcooking may break down pectin and prevent proper gelling. When using either
method, make one batch at a time, according to the recipe. Increasing the quantities often
results in soft gels. Stir constantly while cooking to prevent burning. Recipes are developed
for specic jar sizes. If jellies are lled into larger jars, excessively soft products may result.
Principles of Home Canning
1
1-1
Canned foods for special diets
The cost of commercially canned special diet food often prompts interest in preparing these
products at home. Some low-sugar and low-salt foods may be easily and safely canned at
home. However, the color, avor, and texture of these foods may be different than expected
and be less acceptable.
Canning without sugar
In canning regular fruits without sugar, it is very important to select fully ripe but rm fruits of
the best quality. Prepare these as described for hot-packs in Guide 2, but use water or regu-
lar unsweetened fruit juices instead of sugar syrup. Juice made from the fruit being canned is
best. Blends of unsweetened apple, pineapple, and white grape juice are also good for lling
over solid fruit pieces. Adjust headspaces and lids and use the processing recommendations
given for regular fruits. Splenda® is the only sugar substitute currently in the marketplace that
can be added to covering liquids before canning fruits. Other sugar substitutes, if desired,
should be added when serving.
Canning without salt (reduced sodium)
To can tomatoes, vegetables, meats, poultry, and seafood, use the procedures given in Guides
3 through 5, but omit the salt. In these products, salt seasons the food but is not necessary to
ensure its safety. Add salt substitutes, if desired, when serving.
Canning fruit-based baby foods
You may prepare any chunk-style or pureed fruit with or without sugar, using the procedure
for preparing each fruit as given in Guide 2. Pack in half-pint, preferably, or pint jars and use
the following processing times.
Caution: Do not attempt to can pureed vegetables, red meats, or poultry meats, because
proper processing times for pureed foods have not been determined for home use.
Instead, can and store these foods using the standard processing procedures; puree or blend
them at serving time. Heat the blended foods to boiling, simmer for 10 minutes, cool, and
serve. Store unused portions in the refrigerator and use within 2 days for best quality.
(Ken�–�These�are�Guide�1�Process�Tables,�from�original�USDA�p.�1-25�and�1-33,�sized�as
they�were�on�the�page,�at�about�5-3/8�inch�wide.��I�sized�and�spaced�the�text�in�header
row�purposefully�a�little�differently�than�the�original)
Table�for�Example�A
Recommended�process�time�for�Peaches�in�a�boiling-water�canner
Process�Time�at�Altitudes�of
Style
of�Pack
Jar
Size
0–
1,000�ft
1,001–
3,000�ft
3,001–
6,000�ft
Above
6,000�ft
Hot Pints 20�min 25�min 30�min 35�min
Quarts 25 30 35 40
Raw Pints 25 30 35 40
Quarts 30 35 40 45
Table�for�Example�B
Recommended�process�time�for�Peaches�in�a�dial-gauge�pressure�canner
Canner�Pressure�(PSI)�at�Altitudes�of
Style
of�Pack
Jar
Size
Process
Time
0–
2,000�ft
2,001–
4,000�ft
4,001–
6,000�ft
6,001–
8,000�ft
Hot
and
Raw
Pints
or
Quarts
10�min 6�lb 7�lb 8�lb 9�lb
Table�for�Example�C
Recommended�process�time�for�Peaches�in�a�weighted-gauge�pressure�canner
Canner�Pressure�(PSI)�at�Altitudes�of
Style
of�Pack
Jar
Size
Process
Time
0–
1,000�ft
Above
1,000�ft
Hot
and
Raw
Pints
or
Quarts
10�min 5�lb 10�lb
Recommended�process�time�for�fruit-based�baby�foods�in�a�boiling-water�canner
Process�Time�at�Altitudes�of
Style
of�Pack
Jar
Size
0–
1,000�ft
1,001–
6,000�ft
Above
6,000�ft
Hot Pints 20�min 25�min 30�min
1-
Suggested Preservation Plan for Canned and Frozen Foods
Servings/weekaMy family needs
Per Person Quarts/year
Kind
of Food Serving
Size Suggest Actual
My
FamilybCups/
WeekcQts/
WeekdWeeks
served/yraTotale Canned a Frozena
Example: Family of 4
Fruits 1/2 cup 12 12 48 24 6 36 216 72 144
My Plan:
Fruits—
apples, berries,
peaches, plums,
pears, tomatoes
1/2 cup 12
Juices—
apple, berry, grape,
tomato 1 cup 7
Vegetables—
beets, beans,
carrots, corn, peas,
pumpkin, squash
1/2 cup 16
Meat & Seafood—
red meat, poultry,
shellfish, fish 1/2 cup 14
Soups 1 cup 2
Pickles &
Relishes—
ketchup, fruit
pickles, vegetable
pickles, relish, etc.
— 1/2 cup
Fruit Spreads—
honey, jellies, jam,
syrups, preserves,
etc.
— 1/2 cup
Sauces—
tomato, etc. 1/2 cup 2
aYour family should make these decisions.
b Servings/week for my family = actual weekly servings/person multiplied by number of family members who eat that food.
cCups/week = servings/week multiplied by recommended serving size.
d Quarts/week = cups/week divided by 4.
e Total quarts/year = quarts/week multiplied by weeks served/year.
How much should you can?
The amount of food to preserve for your family, either by canning or freezing, should be
based on individual choices. The following table can serve as a worksheet to plan how much
food you should can for use within a year.
Principles of Home Canning
1
1-
Glossary of Terms
Acid foods Foods which contain enough acid to result in a pH of 4.6 or lower.
Includes all fruits except gs; most tomatoes; fermented and pickled
vegetables; relishes; and jams, jellies, and marmalades. Acid foods
may be processed in boiling water.
Altitude The vertical elevation of a location above sea level.
Ascorbic acid The chemical name for vitamin C. Lemon juice contains large
quantities of ascorbic acid and is commonly used to prevent
browning of peeled, light-colored fruits and vegetables.
Bacteria A large group of one-celled microorganisms widely distributed in
nature. See microorganism.
Blancher A 6- to 8-quart lidded pot designed with a tted perforated basket to
hold food in boiling water, or with a tted rack to steam foods.
Useful for loosening skins on fruits to be peeled, or for heating foods
to be hot packed.
Boiling-water canner A large standard-sized lidded kettle with jar rack, designed for heat-
processing 7 quarts or 8 to 9 pints in boiling water.
Botulism An illness caused by eating toxin produced by growth of Clostridium
botulinum bacteria in moist, low-acid food, containing less than
2 percent oxygen, and stored between 40° and 120°F. Proper heat
processing destroys this bacterium in canned food. Freezer
temperatures inhibit its growth in frozen food. Low moisture controls
its growth in dried food. High oxygen controls its growth in fresh
foods.
Canning A method of preserving food in air-tight vacuum-sealed containers
and heat processing sufciently to enable storing the food at normal
home temperatures.
Canning salt Also called pickling salt. It is regular table salt without the anticaking
or iodine additives.
Citric acid A form of acid that can be added to canned foods. It increases the
acidity of low-acid foods and may improve the avor and color.
Cold pack Canning procedure in which jars are lled with raw food. “Raw pack”
is the preferred term for describing this practice. “Cold pack” is often
used incorrectly to refer to foods that are open-kettle canned or
jars that are heat-processed in boiling water.
1-
Enzymes Proteins in food which accelerate many avor, color, texture, and
nutritional changes, especially when food is cut, sliced, crushed,
bruised, and exposed to air. Proper blanching or hot-packing
practices destroy enzymes and improve food quality.
Exhausting Removal of air from within and around food and from jars and
canners. Blanching exhausts air from live food tissues. Exhausting
or venting of pressure canners is necessary to prevent a risk of
botulism in low-acid canned foods.
Fermentation Changes in food caused by intentional growth of bacteria, yeast, or
mold. Native bacteria ferment natural sugars to lactic acid, a major
avoring and preservative in sauerkraut and in naturally fermented
dills. Alcohol, vinegar, and some dairy products are also fermented
foods.
Headspace The unlled space above food or liquid in jars. Allows for food
expansion as jars are heated, and for forming vacuums as jars cool.
Heat processing Treatment of jars with sufcient heat to enable storing food at normal
home temperatures.
Hermetic seal An absolutely airtight container seal which prevents reentry of air or
microorganisms into packaged foods.
Hot pack Heating of raw food in boiling water or steam and lling it hot into jars.
Low-acid foods Foods which contain very little acid and have a pH above 4.6. The
acidity in these foods is insufcient to prevent the growth of the
bacterium Clostridium botulinum. Vegetables, some tomatoes, gs, all
meats, sh, seafoods, and some dairy foods are low acid. To control
all risks of botulism, jars of these foods must be (1) heat processed in
a pressure canner, or (2) acidied to a pH of 4.6 or lower before
processing in boiling water.
Microorganisms Independent organisms of microscopic size, including bacteria, yeast,
and mold. When alive in a suitable environment, they grow rapidly
and may divide or reproduce every 10 to 30 minutes. Therefore,
they reach high populations very quickly. Undesirable
microorganisms cause disease and food spoilage. Microorganisms are
sometimes intentionally added to ferment foods, make antibiotics,
and for other reasons.
Mold A fungus-type microorganism whose growth on food is usually visible
and colorful. Molds may grow on many foods, including acid foods
like jams and jellies and canned fruits. Recommended heat processing
and sealing practices prevent their growth on these foods.
Mycotoxins Toxins produced by the growth of some molds on foods.
Principles of Home Canning
1
1-
Open-kettle canning A non-recommended canning method. Food is supposedly adequately
heat processed in a covered kettle, and then lled hot and sealed in
sterile jars. Foods canned this way have low vacuums or too much air,
which permits rapid loss of quality in foods. Moreover, these foods
often spoil because they become recontaminated while the jars
are being lled.
Pasteurization Heating of a specic food enough to destroy the most heat-resistant
pathogenic or disease-causing microorganism known to be associated
with that food.
pH A measure of acidity or alkalinity. Values range from 0 to 14. A food is
neutral when its pH is 7.0, lower values are increasingly more acid;
higher values are increasingly more alkaline.
Pickling The practice of adding enough vinegar or lemon juice to a low-acid
food to lower its pH to 4.6 or lower. Properly pickled foods may
be safely heat processed in boiling water.
Pressure Canner A specically designed metal kettle with a lockable lid used for heat
processing low-acid food. These canners have jar racks, one or more
safety devices, systems for exhausting air, and a way to measure or
control pressure. Canners with 16- to 23- quart capacity are
common. The minimum volume of canner that can be used is one
that, will contain 4 quart jars. Use of pressure saucepans with smaller
capacities is not recommended.
Raw pack The practice of lling jars with raw, unheated food. Acceptable for
canning low-acid foods, but allows more rapid quality losses in acid
foods heat processed in boiling water.
Spice bag A closeable fabric bag used to extract spice avors in pickling solution.
Style of pack Form of canned food, such as whole, sliced, piece, juice, or sauce. The
term may also be used to reveal whether food is lled raw or hot into
jars.
Vacuum The state of negative pressure. Reects how thoroughly air is removed
from within a jar of processed food—the higher the vacuum, the less
air left in the jar.
Yeasts A group of microorganisms which reproduce by budding. They are
used in fermenting some foods and in leavening breads.
1-
Index�of�Foods
Guide Page
Apples
Apple-pear jam 7 8
Butter 2 6
Juice 2 6
Pie filling 2 26
Salsa, peach-apple 2 25
Sauce 2 7
Spread with gelatin,
refrigerated
7 12
Sliced 2 7
Spiced crab 2 9
Spiced rings 2 8
Apricots
Halved or sliced 2 9
Puree 2 14
Asian Pears
Halved or sliced 2 20
Asparagus
Pickled 6 13
Spears or pieces 4 5
Beans
Baked 4 6
Dry, with tomato or molasses
sauce
4 6
Italian green, pieces 4 8
Lima 4 7
Pickled dilled 6 14
Shelled and dried 4 5
Snap green and wax, pieces 4 8
Three- bean salad 6 14
Bear
Ground or chopped 5 6
Strips, cubes, or chunks 5 6
Beef
Ground or chopped 5 6
Strips, cubes, or chunks 5 6
Beets
Pickled 6 15
Pickled, no sugar added 6 32
Whole, cubed, or sliced 4 9
Berries
Blackberries, whole 2 10
Blueberries
pie filling 2 27
spice jam 7 9
syrup 2 10
whole 2 10
Currants, whole 2 10
Dewberries, whole 2 10
Elderberries, whole 2 10
Gooseberries, whole 2 10
Huckleberries, whole 2 10
Loganberries, whole 2 10
Mulberries, whole 2 10
Puree 2 14
Raspberries
syrup 2 10
whole 2 10
Strawberries
-rhubarb jelly 7 8
syrup 2 10
Broth, Meat
Brussels Sprouts
Pickled 6 17
Cantaloupe
Pickles 2 11
Pickles, no sugar added 2 12
Carrots
Pickled 6 16
Pickled, baby 6 16
Sliced or diced 4 10
Cauliflower
Pickled 6 17
Chayote
-Pear relish 6 26
-Jicama slaw 6 17
Cherries
Pie filling 2 27
Syrup 2 10
Whole 2 12
Chicken 5 5
Chile con carne 5 8
5 7
Index of Foods
Guide Page Guide Page
Principles of Home Canning
1
1-
Clams
Whole or minced 5 9
Corn
Cream style 4 10
Pickled corn relish 6 28
Whole kernel 4 11
Crab meat
King or Dungeness 5 9
Cranberry
-Orange chutney 2 13
-Spicy salsa 2 23
Figs 2 14
Fish
Blue, mackerel, salmon,
steelhead, trout, and other fatty
fish, except tuna
in pint jars 5 10
in quart jars 5 11
Smoked 5 13
Tuna 5 14
Fruit Cocktail
Mixed 2 18
Fruit Purees 2 14
Grapefruit Sections 2 15
Grapes
Juice 2 15
-Plum jelly 7 10
Puree 2 14
Spread with gelatin,
refrigerated 7 12
Syrup 2 10
Whole 2 16
Greens 4 19
Horseradish sauce
Pickled 6 30
Jam
Blueberry-spice 7 9
Low-sugar peach-pineapple
spread 7 11
Pear-apple 7 8
Standard or long-boil 7 6
With added pectin 7 7
Without added pectin 7 6
Jelly
Apple spread with gelatin,
refrigerated 7 12
Golden pepper 7 10
Grape-plum 7 10
Grape spread with gelatin,
refrigerated 7 12
Standard or long-boil 7 5
Strawberry-rhubarb 7 8
With added pectin 7 7
Without added pectin 7 5
Jicama
Bread-and-butter pickled 6 18
-Chayote slaw 6 17
Spicy relish 6 30
Lamb
Ground or chopped 5 6
Strips, cubes or chunks 5 6
Mango
Chutney 2 16
Salsa 2 24
Sauce 2 17
Meat�Stock�(broth) 5 7
Mincemeat
Festive pie filling 2 28
Mushrooms
Marinated 6 18
Whole or sliced 4 13
Nectarines
Halved or sliced 2 18
Puree 2 14
Okra
Pickled dilled 6 19
Whole or sliced 4 14
With tomatoes 3 12
Index of Foods
Guide Page Guide Page
1-
Onion
-Pepper relish 6 30
Pickled pearl 6 20
Orange Sections 2 15
Oysters 5 12
Peaches
-Apple salsa 2 25
Halved or sliced 2 19
Low sugar peach-pineapple
spread 7 11
Pie filing 2 30
Puree 2 14
Salsa 2 24
Pears
Asian, halved or sliced 2 20
-Apple jam 7 8
-Chayote relish 6 26
Halved 2 19
Puree 2 14
Peas
Green or English, shelled 4 14
Shelled and dried 4 5
Peppers
Hot or sweet 4 15
Jelly, golden pepper 7 10
Marinated 6 20
Pepper-onion relish 6 30
Piccalilli 6 27
Picked bell 6 21
Pickled hot 6 22
Pickled jalapeño rings 6 23
Pickled yellow pepper rings 6 24
Pickled Vegetables
Asparagus 6 13
Beans, dilled 6 14
Beets 6 15
Beets, no sugar added 6 32
Brussels sprouts 6 17
Carrots 6 16
Carrots, baby 6 16
Cauliflower 6 17
Chayote and jicama slaw 6 17
Green tomatoes, sweet 6 24
Horseradish sauce 6 30
Jalapeño pepper rings 6 23
Mixed vegetables 6 25
Mushrooms, whole, marinated 6 18
Okra, dilled 6 19
Onions, pearl 6 20
Peppers, bell 6 21
Peppers, hot 6 22
Peppers, marinated 6 20
Piccalilli 6 27
Squash, bread-and-butter 6 9
Three bean salad 6 14
Yellow pepper rings 6 24
Zucchini, bread-and-butter 6 26
Pickles
Bread-and-Butter 6 9
Dill
fermented 6 7
fresh-pack, quick 6 10
reduced-sodium 6 34
Sweet
14- day 6 11
cucumber slices, no sugar
added
6 33
gherkin 6 10
quick 6 12
reduced-sodium 6 34
Pie Fillings
Apple 2 26
Blueberry 2 27
Cherry 2 27
Mincemeat, festive 2 28
Tomato, green 2 29
Peach 2 30
Pineapple
Low-sugar peach-pineapple
spread 7 11
Pieces 2 21
Puree 2 14
-Zucchini 2 22
Plums
Halved or whole 2 21
-Grape jelly 7 10
Puree 2 14
Pork
Ground or chopped 5 6
Strips, cubes or chunks 5 6
Index of Foods
Guide Page Guide Page
Principles of Home Canning
1
1-
Potatoes
Sweet, pieces or whole 4 16
White, cubed or whole 4 17
Pumpkin
Cubed 4 18
Rabbit 5 5
Relish
Chayote and pear 6 26
Corn 6 28
Horseradish 6 30
Jicama, spicy 6 30
Pepper-onion 6 30
Piccalilli 6 27
Pickle 6 28
Tomatillo, tangy 6 31
Tomato, green 6 29
Rhubarb
Stewed 2 22
-Strawberry jelly 7 8
Salsa
Chile salsa 3 21
Chile salsa II 3 22
Cranberry, spicy 2 23
Mango 2 24
Peach 2 24
Peach apple 2 25
Tomatillo green 3 22
Tomato using paste tomatoes 3 23
Tomato using slicing tomatoes
Tomato/green chile
3
3
24
24
Tomato/tomato paste 3 25
Sauerkraut 6 8
Smoked Fish 5 13
Soups
Dried bean or pea 4 18
Meat 4 18
Poultry 4 18
Seafood 4 18
Vegetable 4 18
Spinach and other greens 4 19
Squash
Pumpkin, cubed 4 18
Winter, cubed 4 18
Stock, Meat 5 7
Strawberry
Puree 2 14
-Rhubarb jelly 7 8
Syrup 2 10
Succotash 4 20
Sweet Potatoes
Pieces or whole 4 16
Syrup
Blueberry 2 10
Cherry 2 10
Grape 2 10
Raspberry 2 10
Strawberry 2 10
Tomatillos
-Green salsa 3 22
Tangy tomatillo relish 6 31
Whole 3 13
Tomatoes
Chile salsa 3 21
Chile salsa II 3 22
Crushed 3 7
-Green chile salsa 3 24
Green tomato pie filling 2 29
Green tomato relish 6 29
Hot sauce, easy 3 16
Juice 3 5
Ketchup
blender 3 18
country western 3 18
tomato 3 17
Pepper sauce, cayenne 3 17
Piccalilli 6 27
Pickled, sweet green 6 24
Salsa using paste tomatoes 3 23
Salsa using slicing tomatoes
Sauce, Mexican
3
3
24
15
Sauce, spaghetti
with meat 3 14
without meat 3 13
Sauce, standard 3 8
Sauce, taco 3 26
-Tomato paste salsa 3 25
Vegetable juice blend 3 6
Index of Foods
Guide Page Guide Page
1-0
Whole or halved
packed in juice 3 10
packed in water 3 9
packed raw 3 11
without added liquid
With okra or zucchini 3 12
Tuna 5 14
Veal
Ground or chopped 5 6
Strips, cubes or chunks 5 6
Regular 4 12
Quick pickled 6 25
Venison
Ground or chopped 5 6
Strips, cubes or chunks 5 6
Cubed 4 18
Zucchini
Bread-and-butter pickles 6 26
-Pineapple 2
3
22
12
With tomatoes
Vegetable , Mixed
Winter Squash
s
Index of Foods
Guide Page
