Blackberry pie is pie compose of blackberry filling, usually in the form of either blackberry jam, actual blackberries themselves, or some combination thereof. Blackberry pie is somewhat sweeter than blueberry pie, usually requiring only a sprinkle of sugar for taste, whereas the number of cups of sugar required for blueberry pie is usually 1/5 the number of cups of blueberries used. Blackberries must be stewed or soaked in water prior to baking to prevent burning, a concern not present in preparing blueberry pie.