Hot Water Bath or Pressure Canner?
The most important piece of equipment in your canning adventures is the canner itself, but a lot of people don’t know what type of canner to get or when to use pressure canning versus a hot-water bath. The simple rule of thumb is that all high-acid foods go into a hot-water-bath canner and everything else must be processed in a pressure canner.
High-acid foods are all fruit products (jams, jellies, preserves, conserves, fruit butters, and marmalades) and anything pickled with vinegar like pickles, relishes, and vinegar-based sauces. The hot-water bath increases the temperature in the canning jar enough to kill bacteria and it also pushes out air bubbles as the content expands. As the jars cool, the air pressure creates the seal that makes the lid pop.
Low-acid foods are all non-pickled vegetables, meat, fish, poultry, and dried beans. The pressure cooker gets much hotter than a bath canner (250°F), and it maintains that heat throughout processing to kill microbes.
Notice there’s no mention of tomatoes here. That’s because tomatoes (which are fruits) can either be water-bath processed or pressure processed. In either case, lemon juice must be added to bring up the acidity level.
A can of corn originally made more than 40 years ago was recently discovered in a California home. When the can was opened, the corn looked and smelled like freshly canned corn, and it even tested safe from contaminants!
Hot-water-bath canners are made of aluminum or porcelain-covered steel. They have removable perforated racks and fitted lids. The canner must be deep enough so that at least 1" of briskly boiling water will be over the tops of jars during processing.
Some boiling-water canners do not have flat bottoms, which are essential for use on an electric range. Either a flat or ridged bottom can be used on a gas burner. To ensure uniform processing of all jars with an electric range, the diameter of the canner should be no more than 4 inches wider than the element on which it is heated.
You need a hot water canner that is deep enough to submerge the jars you’re using. Look for one that has a rack for the jars so they don’t clank together during boiling. Some home preservers use a large stockpot and homemade rack system, but department stores offer very affordable hot-water bath canning kits starting at around $30.
Do not use a saucepan for home canning. It will easily boil over and may not cover your jars effectively. Also, don’t shop for a canner in a secondhand store. The older canners may not have good gaskets and are often missing parts that may be impossible to replace.
By comparison, home-use pressure canners have been extensively redesigned in recent years. Models made before the 1970s were heavy-walled kettles with clamp-on or turn-on lids. They were fitted with a dial gauge, a vent port in the form of a petcock or counterweight, and a safety fuse.
Modern pressure canners are lightweight, thin-walled kettles; most have turn-on lids. They have a jar rack, a gasket, a dial or weighted gauge, an automatic vent/cover lock, a vent port (steam vent) to be closed with a counterweight or weighted gauge, and a safety fuse.
A pressure canner runs about $100 for a 10–16 quart size. However, a pressure canner easily becomes a hot water canner just by leaving the lid off. It can also be used for other culinary efforts, such as tenderizing cheap cuts of meat. If you’re planning to do a lot of canning or more than jam and pickles, get a pressure canner; it offers more options.