Canning 101: Preserving
One of the primary truths of canning has always been that while the jars and rings are reusable, the lids are not. When I teach canning classes, I’m careful to emphasis that those flat metal lids only have one trip through the canner in them and that they lose their mojo once through a boiling water bath.
However, a brand of canning lids called ForJars recently returned to the market and they come sporting a pair of dual virtues that make them nearly irresistible for home canners.
They are free of Bisphenol A (known in shorthand as BPA). Lots of people have turned to canning in recent days to get away from the BPA that lines so many commercially canned foods, only to find out that the lids for canning jars are also lined with the stuff. Typically, I try not to worry about them, comforting myself with the fact that properly canned foods shouldn’t actually be in contact with those lids after processing. Still, it’s a concern.
I bought several dozen Forjars lids at the beginning of the summer, but didn’t end up using them until my marathon tomato canning period that started over Labor Day weekend. I spent two full months passing them up, each time reaching for the disposable lids in my cabinet. I was a little bit wary of them, uncertain whether they’d work. Additionally, since I typically squeeze my canning into the hours after dinner and before bed, there’s often an element of frenzy to my putting up. I always felt like I didn’t have time to teach myself the steps necessary to make the ForJars work.
However, when I was canning all those tomatoes, I reached into the cabinet and realized I was completely out of regular mouth lids. I had to use the Forjars lids. It was trial by fire, particularly since I was canning in both a boiling water canner and a pressure canner that night. I had a moment of panic after the processing was complete but before the jars had fully sealed, when I realized I hadn’t left the rings as loose as was necessary for proper venting, and yet still, it all worked. All the jars sealed and sealed strong. They pass my standard seal test (grasp edges of lid and lift jar holding nothing but the lid) with flying colors.
What to Know
There are a couple additional steps to ensuring a good seal. When you apply the lids and screw on the bands, you MUST then unscrew the band a quarter turn. This ensures that there’s enough space for the hot air to escape from the jar during processing. Then, when the jars have finished processing and you’ve removed them to the counter, quickly give all the bands a good, quick tighten. This brings the rubber seal into firm contact with the rim of the jar and allows the air tight seal to form.
By Marisa McClellan