Jam is a thick mixture of fruit, sugar that is cooked until the pieces of fruit are very soft and almost formless. It is used as a bread spread, a filling for pastries and cookies and an ingredient for various desserts. Apricot, blackberry, blueberry, boysenberry, cherry, peach, sweet and sour plum, raspberry, and strawberry are among the prepared varieties available. Berry jams such as blackberry and raspberry are available seedless.