Here’s some tips in a 1925 home economics textbook for selecting canning jars, lids, and rings:
Glass jars rather than metal cans should be used for home canning. Jars should be constructed so that there is no contact of the fruit with the metal, hence a jar having a glass cover is desirable. A large opening, simple construction, ease in cleaning, and perfect sealing are characteristics of good fruit jars.
Glass jars should be tested before using. Partly fill the jar with water, adjust the rubber and cover, seal, invert the jar. Examine carefully for leakage.
Rubber Rings. – Soft, elastic rubbers should be chosen. It is poor economy to use old rubbers. Rubber after usage becomes hard and inelastic; it may cause imperfect sealing and hence decay of the fruit.
In certain processes of canning, it is necessary to subject the jars provided with rubber rings and covers to long periods of boiling or to the intense heat of a pressure or steam cooker. When such a method is followed it is especially necessary that rubber rings of good quality be used. To meet this requirement, the United States Department of Agriculture advises that rubber rings conform to the following:
- Inside diameter of 2 1/4 inches (for a jar of standard size).
- Width of ring or flange from 1/4 to 12/32 of an inch.
- Thickness of 1/12 of an inch.
- Tensile strength sufficient to “stretch considerably and return promptly to place without changing the inside diameter.”
- Firm enough so that no crease or break shows after it has been tightly folded.
School and Home Cooking (1925) by Carlotta C. Greer
It’s easier now with the metal lids, but even those should not be used more than once.
It’s definitely easier now with the metal “self-sealing” lids.
Once apon a time…. a long long time ago….. We saved glass jars from Mayo and other store bought stuff to use for canning also… that started when we could use the metal lids.
Then the jars got thinner and then they went to plastic.
I sometimes wonder how food processing plants “can” food using plastic jars. It seems like the foods in those jars couldn’t be heated to high temperatures, but I don’t know anything about commercial canning processes.
We always had Ball jars – living in Muncie, IN the home of the Ball Brothers and the first factory making Ball jars! My great grandfather was a glass blower for the Ball Bros. But they modernized and used forms instead of hand blown… So he drove a wagon to deliver materials to different parts of the factory and to take cases of jars to the train depot! My grandmother worked for them during WWII when they made munitions and battery casings. She retired from there and we always canned veggies and fruit!
It’s fascinating how your ancestors worked at the Ball Brothers factory. Until I read your comment, I hadn’t realized that glass jars were hand blown years ago. And, it’s also really interesting that the factory shifted to making munitions and battery casings during WWII. I never would have guessed that a factory could be shifted from glass jar production to munitions and battery casings production.
Thanks Sheryl! At one time they used glass as part of the battery casings… it is leak proof if not broken. My sister has the paper weight my ancestor made (on company time) seems that if there was a lull in orders the glass blowers all made little things as gifts for their families – at one time there was a set of cups made from the blue/green glass that the original jars were made of. They were broken over time. As a child my grandmother had the last one in her bathroom for her teeth!
I am familiar with those things, but I’m very happy I don’t have to use them.
When I first got married, many years ago, my mother-in-law actually still occasionally used zinc lids with the rubber rings. She gave me the jar in the picture. It was filled with canned cherries. We ate the cherries and I set the jar aside to return to her, but somehow never remembered to give it to her – and, of course, she has been gone for many years at this point in time. So I probably should just discard the zinc lid, but it holds memories for me, so I’ve always kept it.
I didn’t realize your photo had a personal history. That’s wonderful.
Preparing this post brought back a lot of warm memories.
Very interesting!
It’s nice to hear that you enjoyed this post.