Preserving Vegetables by Canning
Canning is a very old method of food preservation that was extremely useful in the days before refrigeration. Basically, a jar is filled with food, fitted with a lid, and boiled in water for a period of time. The boiling should both kill any harmful organisms in the food and force air out of the jar, sealing the lid to the top with a vacuum. The great fear when it comes to canned garden vegetables is botulism, a potentially deadly bacterium that thrives in wet, low-oxygen, low-acid environments. There are two distinct methods of canning: water bath and pressure. Water bath canning is good for fruits and pickles, which are high in acid and don’t harbor botulism spores well. Vegetables, however, are very low in acid and require much more intense pressure canning. You need to be especially careful when canning vegetables. If you’re at all unsure about the success of your project, it’s better to just bite the bullet and throw it away. Preserving vegetables by canning requires some special equipment. You’ll need canning jars with two-piece lids – one piece is flat with a thin rubber seal on the bottom and the other is a metal ring that screws around the top of the jar. For water bath canning, you really only need a very large pot. For pressure canning, you absolutely need a pressure canner, a special pot with an exhaust vent, pressure gauge, and lid that can be clamped down. Canning can be tricky and doing it wrong can be dangerous, so read up some more before you try it on your own. The National Center for Home Food Preservation is a good source of more detailed information.
