Hi, I've attempted to make a few types of jams and jellies in the past few weeks. In every case, I've used pectin, and in every case, they just haven't set properly. The consistency ranged from completely watery to sort of slimy. I'm following the directions very precisely and just can't figure out what I'm doing wrong! I tried making blueberry/mango jam, pear/persimmon jam, and grape jelly. Any suggestions?