Canning is an important, safe method of food preservation if practiced properly. Home canning has always meant great-tasting food. Canning lets you take charge of the quality and character of the food you eat. There are no preservatives. No chemicals. Nothing but natural, nutritious fruits and vegetables – picked fresh, then preserved at the peak of perfection.

Pressure canning is the only safe method of canning all vegetables (except tomatoes). Jars of food are placed in a pressure canner which is heated to a temperature of at least 240°F. This temperature can be reached only in a pressure canner.

For the purpose of canning, all foods are divided into two classifications. This is determined by the amount of natural acid present in the food or the acidification of the food. The two classifications are: high-acid foods and low-acid foods.

High-Acid Foods and Acidified Foods

These foods have naturally high levels of acid or have a sufficient amount of acid added to them. Bottled lemon juice, citric acid or vinegar labeled 5 percent acidity are somethimes added to recipes to increase acidity. The boiling water method of processing is adequate for high-acid foods. Generally, all fruits and soft spreads are classified as high-acid foods. Figs and tomatoes require the addition of an acid so they may be safely canned using the boiling-water method. Pickles, fermented food – sauerkraut, brined pickles and fruit – fall into this category.

 Low-Acid Foods

These foods have very little natural acid. Vegetables, meats, poultry, seafoods are in the low-acid group. Soups, stews, meat sauces and other recipes which contain a combination of high-acid and low-acid ingredients must be processed as a low-acid product.

Boiling-Water Method

High-acid foods are processed in a boiling-water canner or larger pot with rack. The heat is  transferred to the product by the boiling water which completely surrounds the jar and two-piece cap. A temperature of 212°F is reached and must be maintained for the time specified by the recipe. This method is adequate to destroy molds, yeasts and some bacteria.

A boiling-water canner must not be used for processing low acid foods. The boiling-water method never reaches the high temperature needed to destroy certain bacterial spores and their toxins, which can produce botulism.

 Pressure-Canning Method

Low-acid foods must be processed in a pressure canner. In order to destroy all bacteria, their spores and the toxins they produce, low-acid foods must be heated to a temperature of 240°F and held there for the time specified by the recipe. At 10 pounds pressure, using a weighted-gauge canner or using a dial gauge at 11 lbs. pressure, the temperature will reach 240°F, which is hot enough to destroy the bacterial spores that emit toxins.

 Peach Pickles (about 6 pint jars)

8 pounds peeled peaches (small to medium sized)

6 ¾ cups sugar

4 sticks cinnamon (2 inches long)

2 tablespoons whole cloves, crushed

1 tablespoon ginger

1 quart vinegar

Wash and peel peaches with sharp knife, and drop into a solution of ½ teaspoon ascorbic acid and 2 quarts of water.

Dissolve sugar in vinegar in saucepot and put on range to heat. Boil 5 minutes and skim. Add spices (tied loosely in cheesecloth).

Drain peaches. Drop drained peaches into boiling syrup and cook until they can be pierced with a fork, but not soft. Remove from range and allow peaches to set in syrup overnight to plump. Bring to a boil and pack into hot jars, leaving 1/2-inch headspace. Cover with syrup, leaving ½-inch headspace. Remove air bubbles. Wipe jar rims. Adjust lids. Process 20 minutes in boiling water bath.

To learn more about canning, Melinda Houser is offering a hands-on class using the pressure canner and water-bath canner. Each person will preserve 2 jars of food. Call Cooperative Extension in Lincolnton, 704-736-8461, to register. Cost is $4.00 per person. This workshop will be presented at the James W. Warren Citizens Center, Lincolnton on July 15th from 1:00 p.m.- 4:00 p.m.

Melinda M. Houser, FCS Agent, NC Cooperative Extension