If you’re lucky enough to have delicious fresh tomatoes from your garden then you know that flavor is worth preserving so you can enjoy them year-round. There are several things to consider when thinking about preserving your tomatoes safely.
Vine-ripened, disease-free, firm tomatoes are the best for canning. Tomatoes aren’t as acidic as they used to be so you need to add acid to home-canned tomatoes. This helps to guard against botulism. Add two tablespoons of bottled lemon juice per quart of tomatoes; one tablespoon for pints. You can use four tablespoons of 5% vinegar per quart (two tablespoons per pint) of tomatoes instead of lemon juice but that can cause undesirable flavor changes.
To remove skins from tomatoes, wash and dip into boiling water for 30-60 seconds or until the skins split. (Dipping them with a cheesecloth pouch works well.) Then, dip the tomatoes in cold water, remove the skins and cores and crush, half or leave whole.
Whole, halved or crushed tomatoes can be hot or raw packed and processed in a pressure or boiling water canner. Pressure canned tomatoes don’t look as pretty as tomatoes canned in a boiling water canner but the pressure-canned tomatoes are a higher-quality, more nutritious product. You can add one teaspoon of canning salt if desired. Leave 1/2 inch of headspace.
If using the pressure canner method, crushed tomatoes should be hot packed. Pints and quarts can be processed for 20 minutes at six pounds of pressure or for 15 minutes at 11 pounds of pressure. Hot or raw-packed whole or halved tomatoes packed in water in pints or quarts can be processed for 15 minutes at six pounds of pressure or 10 minutes at 11 pounds of pressure.
To process in a boiling-water canner, whether they are hot or raw packed in water, pints should be processed for 40 minutes and quarts for 45 minutes. If you are more than 1,000 feet above sea level, increase that time by five minutes. To see a map of the areas of Missouri that are above 1,000 feet of sea level go to: http://extension.missouri.edu/p/GH1451.
Freezing tomatoes is an easy way to preserve them. Just wash and dip them in boiling water for 30 seconds. Then peel and core them. You can freeze them whole or in pieces. Pack the tomatoes into a container leaving one inch of headspace and then seal and freeze. It is best to use frozen tomatoes for cooking because they will not be solid when thawed. Frozen tomatoes work well in crock pot soups, stews and chili.
University of Missouri Extension has a variety of guide sheets on home food preservation. Our Tantalizing Tomatoes guide sheet can be found at: http://extension.missouri.edu/p/GH1456.
To view this article online, go to http://missourifamilies.org/features/foodsafetyarticles/fdsfty62.htm