Home Canning Cardinal Rules for First-Time Food Preservers

Reader Contribution by Mary Moss-Sprague
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Our lives may have been turned topsy-turvy with the global health pandemic, but the can-do spirit of many people is very much alive and well. Many are turning to nature both for comfort and sustenance. That’s a very good thing, especially when it comes to growing and preserving our own food.   

As a trained and certified Master Food Preserver, one of my main concerns about food preservation is that of food safety. It doesn’t do any good to go through the process of canning or otherwise preserving foods if it is done incorrectly and unsafely. If you’re an old hand at canning, you know how important it is to adhere to processing procedures and times, good for you! If, however, you’re new to this time-honored skill, keep in mind that established recipes and procedures exist for a reason.

Crops Change: Follow Latest Guidance 

Many newer food preservation books are on the market now, but I will confidently recommend the always-reliable Ball Blue Book publications for sound recipes and instructions. If it’s more than five years out of date, I’d strongly recommend replacing it with a current edition.

The chemistry within vegetables changes with hybridization and other genetic factors, which influence the natural acidity, so recipes and processing times may be different from before.

Don’t Skip the Acid

Without exception, it is not okay to skip adding lemon juice or other acidifier to canned tomatoes prior to processing! Maybe Grandma never did it, because decades ago, many tomato cultivars did contain a lot more acid. That’s not the case today.

Simply put, shortcuts are a no-no when it comes to preserving food. Some time back, a friend of mine canned two dozen jars of tomatoes. The next day, she realized that she’d forgotten to add the lemon juice. She called and asked me if she could safely add it and just reseal the jars.

“Nope,” I told her. “You’ll have to dump it all into the compost.” If she had discovered her error immediately after processing while the jars were still hot, she could have opened the jars, added the lemon juice, put on new lids, and reprocessed the tomatoes for the prescribed time. However, many hours had passed and the product had completely cooled, so there was no way to salvage the tomatoes — the risk of botulism was too great. I’m sure her family was grateful for her diligence.

Strictly Adhere to Processing Instructions

Also, never, ever assume a “good enough” attitude when it comes to processing times. If 35 minutes per batch is what’s needed, don’t skimp and turn off the heat after 27 minutes. That isn’t enough time; don’t do it! Waiting may be tedious, but you don’t want to put yourself and others at severe risk of becoming ill.

Some people choose to ignore or modify certain basic food-safety rules and pooh-pooh “the old ways.” For instance, I’ve seen some directions for canning meats that use a water-bath canner rather than a pressure canner. That is never safe.

A few years ago, a college student in a nearby town had a severe head cold, so her parents brought her a jarful of homemade (and improperly-canned) chicken soup. She consumed just one spoonful, realized it was “off,” and spent the next five months on a ventilator due to botulinum toxin. Fortunately, she survived; that’s a usually-fatal food poison.

If you’re infected with the botulinum toxin, you have only one chance — one time — to counter it with a specific drug. A second incident? You’re toast. That’s why canning meats must be done in a pressure canner. No exceptions.

Now, you may think, “Oh, she sounds like an old fogey. That was then, this is now.” But, as I said before, there is a reason why we have food test kitchens and why it’s so important to follow established recipes and preservation procedures. They’ve been time-tested and must be followed in the interests of safety.

Food Canning Kitchens: For Adults Only

Finally, do keep young children and four-footed pets out of the food prep and canning area. Children over the age of 11 or 12 can help wash produce and do other tasks ahead of time, but they should be banished from the kitchen when you get to the point of loading and unloading jars into and out of the canners. Red-hot stoves and large pots of boiling liquids create a dangerous environment, and spills do happen.

Maybe the kids could monitor the timer and inform you when it buzzes? They’ll feel proud and useful, and stay safe. After the jars are out and safely settled on a towel or rack on the counter to cool, the kids can return to watch to see the lids snap down as they seal with a pop! — but no cheating by pushing down on the lids.

Here’s to a bountiful, safe growing and preservation season.

Photo byJustina Nagy

Mary Moss-Sprague is a certified Master Gardener and Master Food Preserver in Corvallis, Ore., and author of Stand Up and Garden: The No-digging, No-tilling, No-stooping Approach to Growing Vegetables and Herbs. Read all of Mary’s MOTHER EARTH NEWS postshere.


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