Theres no pectin in your mix. You need some in the custard during the setting process. The next time you make it, put in some jam or other kind of preserves (a little bit of peach jam or orange marmelade) and then refrigerate the batter to let it set for several hours after cooking it in the pot. pectin is essential for preventing crystalization in ice cream. Also, do not process the ice cream to the point of freezing it entirely. After you process it into a semi-hardened state, at the theshhold point of which is is soft serve, you want to take it out of the machine, put it in a container and then in the freezer for it to finish congealing.