​Home Canning Basics

Home-canned peaches

​Tennesseans love to preserve their produce. From peaches (shown) to green beans, tomatoes, pickles and more, home canners should take care to follow proper procedures to ensure food safety. Contact your local UT Extension Office or visit the website for the National Center for Home Food Preservation ​for more information. 

Submitted by Janie Burney, University of Tennessee Extension Professor and Nutrition Specialist, Department of Family and Consumer Sciences

Are you beginning to feel the canning fever? If you are thinking about preserving food this summer, start planning and preparing now! Start by checking your equipment and supplies. Proper equipment in good condition is needed for safe, quality home canned food.

If you’ve not yet purchased your canners, there are two types to consider: boiling water canners and pressure canners. A boiling water canner is used for canning acid or acidified foods like most fruits, most pickles, jams and jellies. Boiling water canners cost about $30-$100, or can be assembled yourself with a large stock pot, secure lid and rack to keep jars off the bottom of the pot.

A pressure canner is essential for canning low acid foods such as vegetables, meats, fish and poultry. These foods require higher temperatures, 240°F and above, to be sure and kill the toxin–producing spores of the bacteria Clostridium botulinum. If not killed, these spores can grow and produce a deadly toxin (poison) when the jars cool and are stored in room-temperatures. A water-bath canner only reaches 212°F, which is not high enough to kill the spores.

You can choose between two types of pressure canners: a dial gauge canner or a weighted gauge canner. Most steps in managing the pressure canning process are the same, but the two styles have different types of gauges to indicate the pressure inside the canner. Expect to spend $100-$150 or more on a pressure canner.

If you use a dial gauge canner, it’s important to have the gauge tested for accuracy before each canner season or if you drop or damage your gauge. Contact your local Extension agent to find out where you can get your dial gauge tested. If your dial or weighted gauge canner has a rubber gasket, be sure it is flexible and soft. If it is brittle, sticky, or cracked, replace it with a new gasket. Also check that any openings, like vent ports, are clean and open.

You’ll also need jars and lids for canning. If you need jars, new jars are a worthwhile investment (versus purchasing used jars from a yard sale or flea market) because very old jars may break under pressure and heat. Extension recommends Mason-type jars of standard sizes (e.g., half-pint, pint and quart). Make sure those jars are manufactured and sold for canning purposes; not all glass and Mason-style jars are tempered to prevent breakage with the extreme heat and temperature changes during canning. Two-piece canning lids with flat lids and ring bands are recommended. Never reuse flat lids, but you can reuse ring bands provided they are not rusted or bent. Follow manufacturers’ advice for preparing your jars and lids. 

It is not too early to begin gathering your other equipment and supplies for canning. A jar funnel for filling jars, a magnetic wand to handle flat lids and a plastic debubbler (or rubber spatula) are useful utensils and can be found where canning supplies are sold. 

A final must is reliable, up-to-date canning and other food preservation instructions. There are very serious food safety risks with canning if you follow unsound recommendations. Reliable, up-to-date canning instructions are available from your local Extension agent or online from the National Center for Home Food Preservation (nchfp.uga.edu). Extension agents offer canning classes in some counties in Tennessee.

When the fresh fruits and vegetables start growing in the coming weeks, you will be ready to preserve and enjoy them all year!

Through its mission of research, teaching and extension, the University of Tennessee Institute of Agriculture touches lives and provides Real. Life. Solutions. ag.tennessee.edu



Dr. Janie Burney, UT Extension Family and Consumer Sciences, 865-974-7402, jburney@utk.edu