Hinotori said:
Not supposed to use pressure canners on a flat top stove because of how the stoves cycle heat. There are worries that the temperature in the canner won't stay steady enough to kill botulism.
We got a propane stove for outside for my canning. It also has the advantage of not heating or steaming the house up when I can. This is what my uncle has used for the last 30+ years. After I set off a fire alarm during a big juice canning session with the steam from the water bath canner, I'm all for outside canning.
I've never heard of this. Do you have a source?
I've read that there is some danger to the stovetop itself. If you took a stove apart, you would see that there really is nothing more than a sheet of glass-like material. The burners are spring-loaded against the top. The model I looked in did not have any supports at all, no even in the center. So putting a fully-loaded canner on a flat-top stove could certainly be a problem. Personally, I've used an AA-921 without incident on 2 flat-top stoves.
Another issue is heat transfer into a pan. I have a few Revere copper pans that were wedding gifts to my mother. They are very thin and are not flat enough to get even heat transfer from the flat-top stove. Same with cast-iron pans. The cast iron seems OK when cold but my pans deform a tiny bit with heat and start burning in the center. If you have a super-duper canner, especially from All American, this won't be a problem.
So there are some concerns about using a flat-top stove but I've not heard that cycling heat is an issue. Where did you hear/read about it?