We should be clear, crab apples are not sweet, at least not in terms of regular apples. We planted this tree a couple of years ago and this is the first year for it to fruit. Crab apple trees are vigorous and grow rapidly compared with regular apple tree stocks.
The fruit are about the size of a golf ball, maybe a little smaller. The apple itself has firm, crunchy flesh and is tart—a granny smith is a sweet apple in comparison. But there is a secret to the sweet crab apple. If you wait for them to ripen to when the sugar concentrates at the center of the fruit, taking on a darker, slightly transparent texture, that is the time eat these. Yes, they are still tart, but they also possess a sweetness. Naturally, these apple are good for hard ciders and cooking. Click on the image for a larger view.