I used liquid pectin, and today L decided we needed to add another package. So we added more pectin, more sugar, and reprocessed. I did the spoonful-on-a-plate test and I think it will turn out great this time. We did the same to the plumeria jelly we made the same day, using the same recipe.
I hope it works this time. It seems to me like the pectin isn't as strong as it used to be or something- I invariably need at least 2 packages. L tried to make grape jelly using Welch's unsweetened grape juice and she finally gave up 4 packages later, with so much sugar added that it tasted kinda like a grape candy lollipop.
I'm wondering...Did you double up your recipe because this often causes the pectin not to set or has your pectin expired? Does pectin expire, I don't know if it does or not. Well anyway, just a couple of thoughts. I had muscadine jelly not set up because of one of these reasons and I use low-sugar pectin but if made great pancake syrup.