Preserving food at home - key rules ensure safety and success

August 13, 2008|By LYNN LITTLE

More in gardening and farmers' markets. people are trying to increase the number of fruit and vegetable servings for health and to trim food costs. And cable TV food shows are stimulating interest in cooking.

So home cooking and food preservation are on the rise.

Preserving food at home is not difficult; however, it is important to follow some key rules for preserving food by canning and freezing:

o Choose fresh fruits and vegetables free of dents, bruises, insect damage and mold.

o Preserve foods as quickly as possible after harvest, preferably within 24 hours.


Choose an up-to-date, tested recipe and follow the directions exactly. You can find recipes online or at your local library. Following directions is critical. The dangers in varying a recipe - adding more of one ingredient and less of another - can alter the chemical balance required to preserve food safely and can compromise quality.


For example, in recipes for homemade salsa, tomatoes are typically the high-acid foods, while onion and green peppers are the low-acid foods. Increasing the quantity of onions and green peppers, but reducing the quantity of tomatoes alters the balance between high- and low-acid foods. Changes in a recipe change the results that could threaten food safety and quality.

Read and follow directions and safety recommendations for cookware used in home food preservation. Dial pressure gauges on a pressure canner should be checked annually. You can call Maryland Cooperative Extension-Washington County at 301-791-1504 to make an appointment to have your dial pressure gauge checked.


If you plan to freeze fruits and vegetables, follow the recommendations for preparation, including blanching and packaging.

Use recommended food storage containers in good condition. Glass canning and jelly jars that are free of chips, nicks and cracks and used previously only for food can be sterilized and re-used. Buy new lids and re-use screw bands only if they are free of rust and dents that may inhibit their ability to seal. Canning jars are recommended for all canning because they are tempered to withstand heat during the water bath and pressure canning process.

For proper storage of frozen foods, it is important to use containers designed specifically for freezing foods. You can use rigid containers (either glass or plastic), flexible bags and wraps and vacuum packaging. Be certain that all containers are washed in hot, soapy water, rinsed and drained prior to use.

Use common sense

Label and date home-canned or dried foods and store them in a cool, dry place, such as a pantry or closet; label and date fresh frozen foods as well. As a general rule, use within a year,

Use common sense. If the seal on a canning jar has failed or a jar leaked, discard it. If food is off-color or has an unusual texture or odor, throw it out without tasting it.

Home food preservation can be safe, successful and fun, but it is important to follow directions exactly. You will be able to enjoy summer fruits and vegetables in healthy meals throughout the fall and winter months!

For more information, visit the National Center for Home Food Preservation, which is based at the University of Georgia,; the U.S. Department of Agriculture Complete Guide to Home Canning is available on the National Center Web site. Another excellent resource is the "Ball Blue Book of Preserving," originally published by the makers of Ball canning jars. The "Blue Book" is sold at hardware and other stores selling canning supplies, is available at many libraries and on the Internet at

You can also call Maryland Cooperative Extension-Washington County at 301-791-1504 for answers to your food preservation questions.

Lynn Little is a family and consumer sciences educator with University of Maryland Cooperative Extension in Washington County.

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