Preserving food can be tricky business, and our research turned up a wide spectrum of opinions. The rigorous standards of the USDA, at one extreme, require lab tests for every recipe; the home cook's commonsense approach, also well tested, is at the other—represented by people like Vivian Stein, who's been canning for 51 years. Cornell's Department of Food Science and the home economists at Ball Corp. gave us guidelines for proper technique, and Barry Bluestein, coauthor of two books that deal with the subject, added practical tips on preserving. Here are points to remember:
•Choose only fresh produce. Fruits and vegetables that may already be going bad won't hold up in the preserving process. Be sure to wash produce thoroughly.
•Work with sterile equipment. Wash all equipment with soap and water. Sterilize jars, lids, and rings. Don't forget to sterilize spoons, tongs, and utensils, too (by dipping in boiling water for 30 seconds).
•Always use the proper method. Follow recipes carefully. Just because you get a seal doesn't mean the can is bacteria-free. Low-acid foods must be pressure-canned.
•Store in a cool, dark place. This doesn't mean a cabinet over the stove. Store jars in a basement or refrigerator, away from light.
•Use common sense. If the preserved food doesn't look or smell quite right, don't taste it. Throw it away.