Pectin in Blueberries?
I recently bought some fresh blueberries that congealed when pureed with liquid whether it was soy milk, cow's milk or water. Is there pectin in Blueberries or is there some other explanation for this? I've been making blueberry smoothies for a long time and never had this happen.
Blueberries are also fairly high in acid. Acid and pectin interact in jelling. This is why some preserves recipes, such as strawberry, often call for adding lemon juice or other acid.
Early and late blueberry varieties often have higher acidity than midseason varieties. Jelling action will vary with variety and weather during ripening.