By KARA HAMMES, guest columnist
Even with the late start to this year’s gardening season, I’ve already seen plenty of pictures on social media of people processing and preserving their first batches of produce.
There are many methods for preserving foods, but home canning is a popular option that requires a bit more knowledge and equipment to perform safely than some other preservation methods, such as freezing or dehydrating.
Whether you’re a veteran canner or just starting out, there are several things to keep in mind to ensure you have a safe and productive canning season.
Home canning methods
Home canning is the process of preserving by packing food (typically fruit, vegetables or meat) into glass jars and then heating the jars to create a vacuum seal and kill organisms that may create spoilage or cause disease.
The two safe methods of home canning are boiling water bath canning and pressure canning. Whether a food is high acid or low acid indicates what type of canning method should be used.
High-acid foods and boiling water bath canning:
Foods in the high-acid category can be safely processed by the boiling water method. High-acid foods include:
Most fruits: Apples and applesauce; apricots; berries; cherries; grapes; jams and jellies (fruit only — no low-acid foods such as peppers may be added); peaches; nectarines; pears; pie fillings (fruit only); plums
Acidified and fermented foods: Chutneys; pickled vegetables; pickles (cucumbers); relishes; salsa; sauerkraut; tomatoes (if acidified)
As the name implies, during the process of boiling water canning, heat is transferred to the food by the boiling water that surrounds the jar. Maintaining a temperature of 212 degrees F for the time specified in an approved recipe is necessary to destroy molds, yeasts, enzymes and some bacteria.
Boiling water canners cost about $30 to $100, or can be assembled yourself with a large stock pot, secure lid, and rack to keep jars off the bottom of the pot.
Low-acid foods and pressure canning:
Low-acid foods lack the acidity needed to prevent the growth of bacteria and spores that can survive the temperature of boiling water (212 degrees F). Temperatures inside pressure canners reach higher than boiling water canners (240 degrees F and above as compared to about 212 degrees). Low-acid foods include:
Most vegetables: Asparagus; beets; carrots; green and dried beans; okra; peas; peppers; potatoes; pumpkin; sweet corn
Meats — Beef and poultry; mincemeat pie filling; seafood; wild game
Combination foods — Meat sauces; soups and stews
There are two different types of pressure canners: dial gauge canners and weighted gauge canners. Most of the steps of the canning process are the same regardless of the type of pressure canner used, but the two styles use different methods to indicate and control the pressure inside the canner. Expect to spend $75 to $150 or more on a pressure canner.
Using safe equipment?
All canner types should be inspected at least annually to ensure equipment is in good shape and functioning properly. This is especially true for pressure canners.
For either type of pressure canner, check that the rubber gasket is soft and flexible. If it is brittle, sticky or cracked, then replace it with a new gasket. Also, check that the pressure plug is in place and any openings, like vent ports, are completely clean and open.
If you use a dial gauge canner, then it’s important to have the gauge tested for accuracy before each canning season, or if you drop or damage your gauge. To get your dial gauge checked, you may be able to send it back to the manufacturer, or Purdue Extension Brown County provides canner inspections and gauge testing by appointment. Please call 812-988-5495 or email [email protected] to schedule a time for testing.
Home canning can be a great option to make fresh foods available year-round while also providing an opportunity to experiment with recipes and flavors that you can’t easily find in stores, but it’s important to use the appropriate equipment and follow safe, research-tested recipes.
If you are interested in canning, there’s a lot more to know that what I’ve covered in this column. Other excellent reference options include:
Purdue Extension Publication HHS-799-W “Basics of Home Canning”
Penn State Extension “Let’s Preserve” fact sheets
USDA “Complete Guide to Home Canning”
University of Georgia “So Easy to Preserve”
Ball “Blue Book”
