It may be best to dip your toes into canning by using the boiling water bath canning method instead of pressure canning. Boiling water canning is less complicated and requires less-expensive equipment.
However, you can use water bath canning only for acid foods. That includes berries and all other fruits, and sauerkraut and other fermented products. Tomatoes are right on the line between acid and low-acid foods — you can use the boiling water bath method if you add extra acid (lemon juice or citric acid, for example) to the tomatoes when you process them.
It’s vitally important to follow canning recipes and guidelines precisely. Adding or eliminating ingredients can affect the food’s acidity, which could affect the processing time required to an unknown degree. Canning recipes have been scientifically tested to make sure bacteria or other contaminants don’t spoil your hard work or make people sick.
Also, make sure your jars are made for home canning. Check that they’re not chipped. Use new lids each time.
You can buy a boiling water canner if you want to, but all you really need is a pot large enough to be able to cover jars with one or two inches of water, plus another one or two inches above that to allow the water to stay at a full rolling boil. You’ll also need a rack that fits in the bottom of the pot, so water gets underneath the jars, too.
Plus, you’ll need to know if you’re more than 1,000 feet above sea level. At elevations above 1,000 feet, water boils at temperatures lower than 212 degrees. That means you’ll need to increase the processing time as indicated in recipes. One way to find your elevation is to go to the U.S. Geological Survey website.
Of course, there are a host of other considerations you’ll need be aware of. A good place to start is the National Center for Home Food Preservation. The site contains detailed canning information, a free online home study course and downloadable PDFs of the U.S. Department of Agriculture’s Complete Guide to Home Canning. You can also purchase the USDA guide from Purdue University.
Chow Line is a service of Ohio State University Extension and the Ohio Agricultural Research and Development Center.