Originally, all apple trees were crab apple trees, producing small, sour fruit. Over the millennia, we have used selective breeding to produce the large, sweet apples that we now have. Anything over two inches (5 cm) is an “apple.” Anything under two inches is a “Crab Apple.” Crab apples may be as small as 1/4 of an inch (1/2 a cm) — smaller than some berries!
Though crab apples can be red, green or yellow, all are very sour. Some are used for jam and jelly making; some are used for cider and crab apple wine; some, such as Snowdrift Crab Apples, are so small and fiddly they are best left on the tree for our feathered friends.
Good jelly can be made from Adams, Centennial, Chestnut, Montreal Beauty, Robinson, and Transcendent Crab Apples. Doglo Crabs make a good applesauce and a ruby-red jelly. Hyslops make a deep, orange coloured jelly.
Varieties include Adams, Almey, Centennial, Chestnut, Dolgo, Hyslop, Katherine, Montreal Beauty, Professor Sprenger, Profusion, Radian, Robinson, Royalty, Snowdrift, Transcendent, Van Eseltine and White Angel.
Crab apples are very sour to eat raw, but a good sweetened jelly can be made from them. Some crab apples contain very good tannin for blending into apple cider to give the cider an edge. Crab apples can also be pickled.