Also called a bramble because it grows on thorny bushes (brambles), the blackberry is the largest of the wild berries. Purplish-black in color, it ranges from ½ to 1 inch long when mature. Blackberries are widely cultivated in the United States and are available, depending on the region, from May through September. Imported berries fill the seasonal gap so blackberries are available in some areas year-round. Look for plump, deep-colored berries sans hull. If the hulls are still attached, the berries are immature and were picked too early; the flavor will be tart. Fresh blackberries are best used immediately but they may be refrigerated, lightly covered and preferably in a single layer, for 1 to 2 days. They are wonderful both for cooking and for out-of-hand eating. In Britain, blackberries and apples are a traditional duo for pies.
From The Food Lover's Companion, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.