And here is a nice article about canning jam from the LA Times - I liked this one
because of how she described what to look for as the jam cooks down - I have trouble relying on the thermometer, and found it very helpful as an inexperienced canner.
Yes, once you see that, then you know - I just channeled Steve when I made mine
after the first batch, didn't even use pectin anymore. Hoping I still might be able to make some this year, but it's awful late and I really wanted Blenheim apricots, but they must be done by now.