Q: I have excess tomatoes -- can I cook and freeze them, or do I have to can them? Either way, how do I do it? Guy Cangelosi, Raleigh, NC
AskFN: Making tomato sauce is the easiest way to preserve tomatoes. Cook them in a non-reactive (that is, enameled or stainless-steel) pan according to any recipe you choose.
If you're going to can them, well, there have been whole books written about the best way to do it. We can only suggest you follow a recipe that's well-tested. That said, here are some tips we've found helpful: Plum tomatoes have the best skin/meat/seed ratio for canning; cherry tomatoes tend not to work so well. Tomatoes shouldn't be overripe, or in any way mishandled or damaged. They should be just barely-ripe (better underripe than overripe), and impeccably clean (as should all surfaces and containers). Use about 2.5 to 3 pounds of tomatoes per quart. You don't need to use a pressure cooker; boiling water is generally sufficient.
Tips on Sterilizing Jars:
Properly-handled sterilized equipment will keep canned foods in good condition for years. Sterilizing jars is the first step of preserving foods.
Sterilizing Tips:
Jars should be made from glass and free of any chips or cracks. Preserving or canning jars are topped with a glass, plastic, or metal lid, which has a rubber seal. Two piece lids are best for canning, as they vacuum seal when processed.
To sterilize jars, before filling with jams, pickles, or preserves, wash jars and lids with hot, soapy water. Rinse well and boil the jars and lids in a large saucepan, covered with water, for 15 minutes.
Use tongs when handling the hot sterilized jars, to move them from either boiling water or the oven. Be sure the tongs are sterilized too, by dipping the ends in boiling water for a few minutes.
As a rule, hot preserves go into hot jars and cold preserves go into cold jars. All items used in the process of making jams, jellies, and preserves must be clean. This includes any towels used, and especially your hands.
After the jars are sterilized, you can preserve the food. It is important to follow any canning and processing instructions included in the recipe and refer to USDA guidelines about the sterilization of canned products.
