The Basic Methods of Canning

Two Methods | Two More Terms | Your First Time?

You'll discover that canning is just as easy—and just as rewarding—as cooking.

There's a difference, and it's a big one.

When you cook, you follow a recipe—maybe. You adjust it, very often, to your own tastes or those of your family. You leave out that much garlic in the stew, add nuts to that whole wheat bread recipe. You change the ingredients a bit, to make the recipe truly yours.

You can't do this when you're canning. Experimenting can be dangerous. Time and temperatures have been worked out very carefully for canning. Too little time or too low a temperature means you're not protecting the food against bacteria, enzymes, molds, and yeasts. Too much time or too high temperatures may mean you're needlessly destroying nutrients in the food and damaging its taste. Be fussy in following the directions to the letter.

First, a few basics so you'll understand the why's of canning.

Two Methods

All foods are canned by one of two methods:

1. Boiling water bath method. This is used for acid foods. These include all fruits, tomatoes, sauerkraut and most foods to which vinegar has been added, such as most pickles and relishes.
2. Steam pressure canner method. Used for foods containing little acid. These include vegetables, except for tomatoes, and meats, seafood, and mixes of food that include some low-acid foods.

All foods, acid and non-acid, contain enzymes and can harbor molds and yeasts, all of which will cause food to spoil. All of these can be inactivated or killed by the heat of the boiling water bath canning method.

The steam pressure canner method is used to destroy another threat against canned food—bacteria and their by-products. These include Salmonella, Staphylococcus aureus, and Clostridium botulinum, the cause of botulism.

Since these harmful bacteria are not a problem in the high-acid foods, there's no reason to use this high temperature method with them. These bacteria will thrive in the low-acid foods and aren't destroyed by the 212°F temperature of the boiling water bath method, but succumb to a recommended period of 240°F heat. So the steam pressure canner method must be used for them.

Two More Terms

Two other terms used in canning should be explained. They refer to packing the jars—putting food in them as an early step in canning.

Raw Pack or Cold Pack: These terms, used interchangeably, refer to putting uncooked food into a jar to which a hot liquid is added.

Hot Pack: This refers to putting into jars for processing food that has been cooked to some degree. Hot pack sometimes requires less processing time, since the food already is partially cooked. Sometimes it takes as long, or longer, because of the denser pack.

Instructions for each food will explain which of these packing methods should be used and the processing time required.

Your First Time?

If this is your first attempt at canning, here are some hints that should make it easier for you:

• Start small. Six quarts of tomatoes or a half-dozen jars of jam or jelly are plenty for this first try.
• Be prepared with everything you need. Jars and fresh lids. All the equipment—and that includes a pressure canner with a gauge that's been tested, if you're pressure-canning. Most important, produce that's at the peak of perfection, ripe but not too ripe.
• Have a large cleared area to work in. Canning takes lots of space.
• Have more time than you'll need. You figure you should have it done in an hour? Then give yourself two hours and feel no pressure.
• And realize that canning is a lot like many other kitchen tasks, baking bread or following a complicated recipe—it gets a lot easier the second time you do it.