It’s Time to Can!
It’s time for you to start gathering your supplies and making preparations for canning the vegetables from your garden or the ones you purchase from many of our local farms. Cooperative Extension is proud to be your research-based information source for home food preservation. From water-bath canning, pickling, jams/jellies, pressure canning, freezing, and drying foods – we have a variety of resources to help get you started.
Since its introduction, home canning has changed greatly. Today, two methods of canning are recommended: boiling water bath and pressure canning. Which process you choose is based on the acid level of the foods. Foods that are high in natural acid, that have been fermented, or that have enough vinegar added to make them high in acid can be processed in a boiling water bath canner. This would include all fruits, tomatoes, sauerkraut, pickles and relishes. Jams, jellies and preserves are also processed in the boiling water bath.
All low‑acid foods need to be processed in a pressure canner. This includes all meats, fish, poultry and all vegetables, except tomatoes. All these foods contain very little natural acid. Mixtures that contain both high‑acid and low‑acid foods, must also be canned in a pressure canner. An example of such a mixture might be okra and tomatoes.
Failure to pressure can vegetables could cause botulism, a life threatening foodborne illness. A temperature of 240 degrees or 11 pounds of pressure is needed to kill the botulism spore. In addition to the temperature, the time needed to destroy bacteria ranges from 20 to 100 minutes. Never guess at the length of time to process food. Cutting the time short can be dangerous. The exact time depends on the kind of food being canned, the way it is packed into the jars and the size of the jars.
When canning, make sure you use recipes found in either the USDA Complete Guide to Home Canning, Kerr Canning and Freezing, So Easy to Preserve or the Ball Blue Book. These are research‑based recipes with reliable processing times to assure a safe product. We have copies of the USDA Complete Guide to Home Canning and Ball Blue Book for sale at the McSwain Center.
Each year I receive calls telling me they have canned their vegetables the “old timey” way as well as some “modern ways”. Open‑kettle canning and the processing of freshly filled jars in conventional ovens, microwave ovens, and dishwashers are not recommended. Steam canners are not recommended because processing times for use with current models have not been adequately researched. We also do not recommended pressuring in excess of 15 pounds. From time to time you will find “canning powders”. These are useless as preservatives and do not replace the need for proper heat processing. Jars with wire bails and glass caps make attractive antiques or storage containers for dry food ingredients but are not recommended for use in canning. One‑piece zinc porcelain‑lined caps are also no longer recommended. Both glass and zinc caps use flat rubber rings for sealing jars, but too often fail to seal properly.
Home canning is a reliable and safe method of preserving food if you follow safe processing procedures. Our hands-on, step-by-step classes for green beans and tomatoes will be held on July 9 and July 30 at 6:00 p.m. Class size will be limited to fourteen. If you are interested in taking one of the classes call the Extension Center at 775-5624 to register and to obtain a list of supplies needed. There is an $8.00 registration fee for each class, which includes your jars, lids and rings.
Before starting to can, make sure your canner is working properly and the gauge is reading accurately. If the gauge is reading incorrectly, or if the canner is operating improperly, the higher-than-boiling temperatures that are required in pressure canning will not be reached. Again this year we will be glad to check your pressure canners at the McSwain Extension Center, 2420 Tramway Road, on Wednesday mornings from 10-11 a.m. or by appointment. We also have several pressure canners that we can loan out for a three-day period.
If this is your first attempt at canning or if you need a refresher, register today for our canning classes. Cooperative Extension has been a reliable source of food preservation information for over ninety years. It’s going to be a great year to “put up” some good locally grown produce.
Susan Condlin is County Extension Director for North Carolina Cooperative Extension in Lee County.