Title: Filling Your Canning Jars Properly
Categories: Info Check
Yield: 1 Servings

PACKING METHODS

There are two ways to pack food into jars; the cold pack method and the hot pack method.

COLD PACK METHOD The cold (or raw) pack is just what the name implies. You pare and cut the vegetables, pack them into jars uncooked, and then cover them with boiling liquid, usually water. Since uncooked foods shrink slightly after processing, and some foods may float to the top of the jar during processing, you must pack them firmly. The cold pack method is for foods like whole tomatoes, which might not hold their shape if cooked before being packed into jars.

HOT PACK METHOD The hot pack method is generally preferred for foods that are relatively firm and easy to handle even after processing. With this method, you pare and cut the vegetables and then precook them briefly in boiling water before putting them into jars and covering them with boiling liquid. Foods prepared this way or more pliable, so they're easier to pack in jars. They don't shrink as much as cold packed foods do.

Processing times in a steam pressure canner are the same for hot packed and cold packed foods. In a boiling water bath canner, hot packed foods require less processing time than foods that are cold packed.

Jars of cold packed foods shouldn't go directly into boiling water in either the boiling water bath or steam pressure canner. Because the food and the jars are much lower in temperature, the jars could break. Put cold packed jars in the canner, add hot water, and then heat to boiling.

HEAD SPACE You'll note that most recipes direct you to pack food and liquid into the jars to within 1, 1/2 or 1/4 inch of the tops of the jars. This room is called head space, and is necessary for expansion of the food during processing.

If you leave too little room at the top of the jar, the food may expand and bubble when air is being forced out from the lid during processing. The bubbling food may leave a deposit on the rim of the jar or the lid seal and keep the jar from sealing properly. If you leave too much room at the top, the surface of the food may discolor, or the jar may not seal properly because there won't be enough processing time to drive a sufficient amount of air out of the jar.

Each recipe gives you the proper head space. As a general rule, leave 1 inch of head space for beets, corn, peas, and other low acid foods; 1/2 inch of head space for acid vegetables; and 1/4 inch of head space for pickles and relishes.

HIGH ALTITUDE CANNING Higher altitudes and thinner air mean boiling points and pressure are affected, so you must make adjustments in timing and pressure. The times given in the majority of recipes are for altitudes of less than 1,000 feet above sea level for boiling water bath, 2,000 feet for steam pressure. If you live at a higher altitude than that, you'll need to increase times or pressures. Check the altitude charts of the region you live to find what adjustments are necessary at your altitude. If your steam pressure canner has a weighted gauge, use 15 pound pressure instead of 10 when foods are processed at any altitude above 2,000 feet.

Source: Vegetable Gardening Encyclopedia Typos by Dorothy Flatman 1995

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