What is the difference between jam and jelly? A common question asked at every craft fair and at most farmers’ markets is, “What is the difference between jam and jelly?” Actually, I can remember the first time this was asked. I thought the customer was joking. It just goes to show you that when you are totally involved with blueberries, you think everyone else is too. How wrong I was! Blueberry jam has the actual berry incorporated into the product whereas blueberry jelly is made from the juice after the pulp and seeds have been strained from the mix.