Berries are not sold in standard half pint containers. When shopping for ingredients, use the weights on the containers as a guideline, but make sure to measure out the berries (gently, to avoid bruising). If you wind up short on one type of berry but have extras of another type, make up the difference with the extras. If blackberries are not available, use 3 cups each of raspberries and blueberries. When pureeing the berries, be sure to process them for a full minute; otherwise, the yield on the puree may be too small. Apple jelly can be substituted if red currant jelly is unavailable.
