I have a sparkling new ice cream machine. The first batch, Philadelphia-style plain vanilla ice cream, worked perfectly. I decided to try a sorbet, and made Lebovitz's Blueberry-banana sorbet, but used less blueberries than in the recipe, because I didn't have enough. I cooled the base in the fridge for 9 hours.
When I took it out to churn it, it was gelled, I assume due to the pectin in the blueberries. I whipped it a bit with a whisk, which broke it up into small lumps, but didn't really returned it to liquid. When I filled it in the ice cream maker, I discovered that it didn't have enough torque. The mass climbed up the dasher, and started rotating with it as one big lump. Eventually (after over an hour, although the instructions say that half a portion of well-chilled base should only take 20 min) it was ready. The texture was OK, not really crystalized, and definitely no lumps, but still I feel that it would have worked better if the mass had been liquid instead of semisolid from the beginning.
What can I do to prevent the blueberries from gelling during the chilling phase next time?
I used 1 banana (90 g peeled), 125 g fresh blueberries, 50 g sugar, 90 g water, and 7 g lemon juice. Everything thrown into a blender and pureed, no heating. Then chilled for 9 hours in the fridge before churning.