This year you finally got your garden to produce a bumper crop of vegetables. You have more tomatoes and green beans that you can eat for right now. Wouldn’t it be nice to put some up so that you can enjoy the fruits of your labor in the winter months? Yes, you can by preserving your harvest by canning.
Which canning method to use? It depends on the food you will be canning. Most all vegetables have a low acidic value, except for tomatoes which are very acidic. High acidic foods are ideal candidates for the open water bath canning method. However, low acidic foods must be canned using the pressure canning method.
The reason is a commonly existing bacteria called Clostridium botulinum that is often present on vegetables and meats. It is a harmless bacteria in the open air. But, when it in a low acid, moist partial vacuum or oxygen free environment it produces a deadly toxin.
I know a few of you will be quick to jump up and tell me the story of great grandma or granny that used to put up dozens upon dozens of jars of beans, squash, pickles, tomatoes, carrots, corn, okra, etc. using the water bath canning method and she lived well into her 90’s.
Ok, that is all fine an good, but modern food science has explained the danger of Clostridium botulinum bacteria. This bacteria is some nasty stuff, a small amount of canned food that has been infected with the spores can be deadly.
The bacteria and spores can only be killed once the temperature reaches 240 degrees F. In water bath canning the temperature reaches 212 degrees F. It is a little shy of the mark.
Pressure canning requires the use of a pressure canner vessel. It is made out of stainless steel or aluminum. It looks like a regular pressure cooker expect that it has a pressure dial on the lid.