I should note that I like my jam on the tart side. The amount of sugar shown is based on how much apricot puree I got from this particular batch of apricots. Because fruit doesn’t grow in standardized quantities (at least the fruit I want to eat) my general rule is to use three-quarters of the amount of sugar per one-part apricot puree. So if you use more, or less, apricots, simply use for each cup of puree, by volume, three-quarters cup of sugar.
Apricots become quite tangy once cooked, so you’ll find this is not very sweet. I don’t recommend using less sugar, since it may not jell correctly. A bit of lemon juice added at the end provides additional balance, and Europeans often crack a few
apricot kernels open and add one to each jar before pouring in the jam, which isn’t meant to be eaten, but gives the jam a subtle, bitter almond-like flavor.