Central Virginia Organic Gardener

"And 'tis my faith that every flower enjoys the air it breathes." - William Wordsworth, 1798

Monday, September 9, 2013


Above: Apples in syrup.

If you grow lots of produce, eventually you probably need to learn to can.  Yes, you can stuff yourself silly with fresh produce, freeze and dehydrate, build a root cellar to keep produce around a longer time, but canning may be the best way to preserve some things, like jams and jellies, pickles, all kinds of tomato products and my "hippy apples" (see post on that).  There are essentially two types of canning: water-bath and pressure canning.  So far, water bath canning is all I do.  This method is a fine way to preserve high-acid foods, like most fruits, tomatoes and pickles.  In water bath canning (though please look up full directions before you do this) you sterilize the glass jars (I guess it is obvious why we don't call this "jarring") and lids, pack them with hot or cold prepared produce, put a lid and ring on it and process the jars for the amount of time recommended in the recipe.  For this you need a canning kettle, jars, lids and rigs, a jar lifter, lid lifter, canning funnel, instant read thermometer and a few other odds and ends.  You can usually purchase the canning accessories as a "canning kit," though the kettle is sold separately.

The other type of canning is pressure canning and is the only safe way to can low-acid foods, including green beans, carrots, meat, fish, and most prepared meals.  Pressure canning involves the use of a pressure canner (like a pressure cooker).  Canning under pressure is necessary because these foods contain too little acid to prevent to growth of the botulism bacteria.

Above: Pear preserves

If you do either type of canning, get a recently published book on canning to learn how to proceed. In recent years, canning guidelines have changed, including increasing amounts of added acids and salt and processing time (for example, many modern tomato cultivars produce "low-acid" fruit. This might be good for a sensitive tummy, but bad for canning, so you must up the acid by adding lemon juice).  Granny's canning recipes might not cut it anymore, and those vintage cookbooks are fun to look at, but do not rely on their canning recipes.  

One last caution: You may see an older recipe in which the jam is "sealed" by pouring a thick layer of parrafin over the top.  This is generally recognized as unsafe.

Happy gardening!  And preserving!


Anita said...

If the canning is not properly done, is it obvious to the person who opens the jar to eat its contents?

Judy Thomas said...

It pretty much is obvious: the lids are not sealed, the lids are bulging, the smell or look of the food is off. High acid canning is pretty safe: botulism (which you might not be able to see or taste) is more possible in low acid foods, but even then, it is rare.