Preparedness Hints

Ensuring Safe Canned Foods

You must ensure the recommended

Acid foods have a pH of 4.6 or lower.

research-based process times, found They include fruits, pickles, in these guides, are used.

sauerkraut, jams, jellies, marmalades,

and fruit butters. Although tomatoes

The processing times in these guides usually are considered an acid food, ensure destruction of the largest

some are now known to have pH

expected number of heat-resistant

values slightly above 4.6. Figs also

microorganisms in home-canned

have pH values slightly above 4.6.

foods. Properly sterilized canned food

Botulism!

Therefore, if they are to be canned as

will be free of spoilage if lids seal and acid foods, these products must be jars are stored below 95°F. Storing

acidified to a pH of 4.6 or lower with

Growth of the bacterium Clostridium

jars at 50°F to 70°F enhances

lemon juice or citric acid. Properly

botulinum in canned food may cause

retention of quality.

acidified tomatoes and figs are acid

botulism--a deadly form of food

Food Acidity

foods and can be safely processed in

poisoning. These bacteria exist either

and Processing Methods

a boiling-water canner.

as spores or as vegetative cells. The

spores, which are comparable to

Whether food should be processed in

plant seeds, can survive harmlessly in a pressure canner or boiling-water Botulinum spores are very hard to

soil and water for many years. When

canner to control botulinum bacteria

destroy at boiling-water temperatures;

the higher the canner temperature, the

ideal conditions exist for growth the

depends on the acidity in the food.

spores produce vegetative cells which Acidity may be natural, as in most more easily they are destroyed.

Therefore, all low-acid foods should

multiply rapidly and may produce a

fruits, or added, as in pickled food.

deadly toxin within 3 to 4 days of

Low-acid canned foods contain too

be sterilized at temperatures of 240°F

to 250°F, attainable with pressure

growth in an environment consisting

little acidity to prevent the growth of

of: a moist low-acid food; a

these bacteria. Acid foods contain

canners operated at 10 to 15 PSIG.

temperature between 40°F and 120°

enough acidity to block their growth,

PSIG means pounds per square inch

F; and less than 2 percent oxygen.

or destroy them more rapidly when

of pressure as measured by gauge.

heated The term "pH" is a measure of The more familiar "PSIG" designation acidity; the lower its value, the more

is used hereafter in this publication. At

Botulism spores are on most fresh

acidic the food. The acidity level in

temperatures of 240°F to 25O°F, the

food surfaces. Because they grow

foods can be increased by adding

time needed to destroy bacteria in

only in the absence of air, they are

lemon juice, citric acid or vinegar.

low-acid canned food ranges from 20

harmless on fresh foods.

to 100 minutes. The exact time

Low-acid foods have pH values

depends on the kind of food being

Most bacteria yeasts and molds are

higher than 4.6. They include red

canned, the way it is packed into jars,

difficult to remove from food surfaces. meats, seafood, poultry, milk, and all and the size of the jars. The time

Washing fresh food reduces their

fresh vegetables except for most

needed to safely process low-acid

numbers only slightly. Peeling root

tomatoes. Most mixtures of low-acid

foods in a boiling-water canner ranges

crops, underground stem crops, and

and acid foods also have pH values

from 7 to 11 hours; the time needed to

tomatoes reduces their numbers

above 4.6 unless their recipes include process acid foods in boiling water greatly. Blanching also helps. But the

enough lemon juice, citric acid, or

varies from 5 to 85 minutes.

vital controls are the method of

vinegar to make them acid foods.

canning.

Personal and Family Preparedness

Vision: Each family uses principles of provident living in their daily lives.

Mission: "Increase awareness and practice of home production and storage.