When I was in high school 69-72, we used to make fudge. It was wonderful. Made it every year at Christmas, then one year about 6 years ago it failed, tried making it again, thinking I did something wrong, and it failed again. It was horrid and grainy. Spoke to other family members and they had the same thing happen. I was ready to pitch the recipe and my husband started reading weights and started playing with the recipe wrote it out and it has been fine since. But I also think there have been some ingredients had changes in them more than weight.