So I'm working on a better recipe for citrus jelly. Online I find several options:
2.25c juice, 3.5c sugar, 1 certo pectin
4c tangerine juice, 5c sugar, 1 box pectin
4c lemon juice, 7c sugar, 2 liquid pectin

I've got about 5c juice and two boxes Sure-Jell pectin so we'll see what I manage to make. I think I'll need both boxes pectin for the juice, then if I can get the sugar right it might even jell.

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So I used 5c juice (mixed citrus), 8c sugar, and 2 boxes Sure-Jell pectin. After adding the pectin, the foam was a bit too solid so I whisked it in (I think the pectin didn't quite disolve or something). Then the sugar wouldn't quite disolve so again I applied the whisk. The mixture jelled practically on the stove and I had to heat it up again 2/3 of the way through pouring into the jars. No risk of THIS batch not jelling. Made 11 1/2pints.

I think next time I'll say one batch is 3c juice, 4c sugar, 1 box pectin and see what we get. Double batch seems to work fine though.