Canning Tomatoes

Vine ripened tomatoes are canned more often than any other produce. Unfortunately, tomatoes are also the one item than spoils most often due to improper canning techniques. To ensure that your fresh tomatoes are not ruined by bacteria during the canning process, you need to follow a few simple rules.

Foods that have a pH value of 4.6 or lower are acidic enough to safely can using just a hot water bath process. Foods that do not have enough acid naturally should either be processed using a pressure canning method, or you must add additional acid during the canning process to lower the pH value to 4.6 or below. Fresh tomatoes might have enough acid to safely can by themselves using a hot water bath method. However, if your tomatoes are overly ripe that will reduce the acid level. To ensure that the canned tomatoes remain safe to eat, you should add 1 tablespoon of bottled lemon juice or 1/4 teaspoon of citric acid per pint of canned tomatoes. You can add this directly to the jar of tomatoes before you seal them.

If you are canning stewed tomatoes or tomatoes with meat sauce, that will reduce the acid level even more and you must use a pressure cooking method to guarantee that the tomatoes will not spoil. Make sure you have a proper seal on your jars and that you process them for the full recommended time to ensure that all bacteria is killed. If you open a jar of canned tomatoes and they smell sour, never eat them. Also, if there is any mold anywhere inside the jar, discard them without tasting them. Make sure that no people or animals will eat spoiled canned foods, as even a small amount of botulism can be fatal.