Canning jam - a VERY HOT jar question

Cafe Society
1

My first time trying to make and can jam from scratch. I understand the need for the glass jars to be VERY HOT. Most sources say to keep them in a pot of almost-boiling water untill needed. Once source suggested (if you had a dishwasher like this) to run them through the dishwasher and use the “heated dry” feature, then leave them in there (hot) untill you needed them. My question…

Why can’t I use my oven to keep the jars hot? Set it at 200 degrees and just leave the jars in there untill they’re ready to be filled?

Thanks,
Jim

2

You can. That’s the way my mother used to do it.

3

If you are trying to sterilize the jars in a hot oven, it will apparently take 1.5-2hrs at 320ishF (vs. 10 minutes on full boil for immersion in water.) Air is a much less efficient conductor of heat than water.
http://www.engenderhealth.org/ip/instrum/inm11.html

If you just want to keep the jars hot, well, it sort of doesn’t make sense, since you just sterilized them in the water, why not leave them there?

If you’re not planning to start with sterile jars, um, please don’t consume the results. Botulism kills.

4

You wouldn’t get botulism from jam (the fruit is too acidic), but if the jars aren’t sterile, mold will get in and ruin it.

5

Ah ha! Sterilization. Got it.

Thanks!

6

It shouldn’t be “almost boiling”, by the way - it should be boiling, and I mean really boiling. You’re going to have to boil 'em to seal them anyway, just crank up the heat and let 'er rip on your big canning kettle. You’ll get so much humidity in the air in your kitchen that when you open your fridge fog will come out.

7

We made our own jelly and jam when I was a kid, and my mother always sterilized everything in a huge pot of boiling water on the stove . . . and she never used that pot for anything else (it was actually too big to use for anything else). We never had a bad batch.