3 Steps for Canning and Preserving Food

Food preservation is a great way to enjoy the taste of locally grown foods throughout the year. Whether you purchase vegetables from a farmer’s market or pick them from your own backyard, preserving food at home can be fun and nutritious. The following are three steps for canning and preserving food.

Step 1: Choose a research based food preservation guide

An up-to-date research-based food preservation guide is needed for preserving food that is safe to eat. These guides can be purchased at bookstores. New food preservers can also visit the National Center for Home Food Preservation website at www.uga.edu/nchfp for information on how to preserve all types of foods by canning, dehydrating or freezing. Canning and freezing guides give step-by-step instructions for preserving hundreds of foods. The recipes have been lab-tested to assure that the end result is a quality product that is safe to consume. This is important because improperly processed food can lead to food borne illness.

Step 2: Assemble the proper equipment

Getting started as a home food preserver will require purchasing some equipment. To preserve various types of food by canning, both a pressure canner and a boiling water bath canner will be necessary. Canning jars, rings and lids are also necessary. Canning jars may be used repeatedly as long as they are not nicked or cracked. Rings can also be used again, but lids must be replaced. Mayonnaise jars and other commercial food jars are not designed to be used more than once. They could break during the canning process, so they should never be used in home canning. Freezing foods at home requires very little equipment. Freezer boxes, can or freeze jars; and freezing bags are used to store food for freezing. For those interested in drying foods a dehydrator can be purchased. However, by using the proper instructions, dehydration can be accomplished outside on hot days or using an oven.

Step 3: Choose the right process

Canning involves heating food in a jar to a high enough temperature to destroy enzymes and bacteria. When canning is done correctly a tight seal is formed that prevents bacteria, yeasts, and molds from entering the jar. A vacuum is formed in the jar and this keeps air out and liquid in. There are two types canning processes that are safe to use depending on the type of food that is to be canned. Low pH foods are high in acid and high pH foods are low in acid. Foods that are naturally high in acid and pickled foods have enough acid to prevent bacterial growth or to destroy bacteria when heated to 212 degrees fahrenheidt. Boiling water bath canning may be used for foods that are high in acid. This includes fruits, acidified fig and tomatoes which have been acidified. When food is canned using this method, after the jars are filled they are placed in a large pot of enough hot water to cover the lids of all jars so that the water is at least 1 inch above the jar tops. The jars of food are boiled for a specified amount of time in the cover pot or canner and removed and allowed to cool.

Low acid foods like meats, green beans, corn and others should always be processed in a pressure canner. This is because low acid foods can be at risk for clostridium botulinum, the deadly bacteria that causes the foodborne illness botulism. Low acid foods must be heat under pressure to a temperature of 240 degrees fahrenheidt for a specified period of time to kill this bacterium. For many low acid foods ten to eleven pounds of pressure is all that is needed. Low acid foods should never be canned using the boiling water bath method, since 212 degrees fahrenheidt is not hot enough to kill clostridium botulinum.

When canning foods at home, altitude must also be considered in processing times and the amount of pressure when using a pressure canner. Canning guides will provide guidance on selecting the proper times, etc. for specific altitudes.

When dehydrating foods, follow the instructions in a research-based food preservation guide or use those that come with the dehydrator is one will be used.

Freezing is a great method to preserve food for the novice preserver. When freezing certain fruits pre-treatment with an anti-darkening agent like ascorbic acid will improve the quality of the product by reducing enzyme activity that causes some fruits to darken when cut. Likewise blanching vegetables that will be frozen serves the same purpose and will result in a fresher tasting, brighter colored product. Food preservation guides provide all the details needed concerning treating fruit and blanching vegetables.