Yesterday when I made apple pie filling, I substituted (non alcoholic) cider for apple juice in a pinch. The recipe calls to mix the juice, sugar and spices in a pot, bring to a "bubble" (? does that mean full boil or simmer?), and then add the clearjel (mixed in first with lemon juice). I had done this once before with apple juice and the jell turned out perfectly. Now, the clearjel/lemonjuice mix didn't seem to want to blend into the cider mixture, it clumped mostly and formed large jelled lumps. Is this because I used cider?

I tried to salvage the mix by straining out the clumps and reheating the batch, trying again with a smaller amount of clearjel mixture.Partial success, the syrup seemed thicker, semi-jelled, but not as thick as the first time I had made it. Strained out the clumps again and resigned myself to thinner pie filling.

Thoughts on what I did wrong?

btw, it tasted fabulous made with cider!