Pressure Canner

[planetologist]

I'm too scared of it to hurry it along lol.

Now try firing porcelain in a home-made kiln at 1300 C

I'm an ignoramus on this - but what's the difference between your canner and a pressure cooker?
I admit that I haven't done any research to find out the answer - just thought I'd ask you experts

What Ananke said is right, but maybe incomplete. It's perfectly possible and safe to can in a pressure cooker. A canner can operate at lower pressure, so that you will lose fewer vitamins at the lower temperatures you can use for acidic foods, but a pressure cooker operates at 1 bar excess pressure =120 C, which is also the maximum for a canner, so you can end up with sterile food. If memory serves this requires 10 minutes at 120C in the coldest part of your jar, which for something smaller than 1.5 litres might be 20 minutes AT PRESSURE (don't count the time for heating up, and don't sue me for food poisoning if my memory is wrong, though you're very unlikely to want to eat food that wasn't sterile: it will loose negative pressure and smell horrible).