Crab apples are edible. They have a sour, sharp taste, but people can eat them in the same way as regular apples. Because of toxins, it is not advised to eat the seeds or the core.
A raw crab apple is much more bitter and acidic than a regular apple. Because of this, people often cook or bake them with sweeteners, such as sugar, honey and other fruits. Sugar is particularly useful for turning the crab apples into jams, jellies, chutneys, fillings or sauces. They can also be used for drinks, such as cider or juice. Like regular apples, crab apple seeds contain trace amounts of cyanide. Eating too many seeds can cause stomach discomfort and is potentially fatal, especially to pets. Remove the seeds before consuming, and do not eat the core.