Peanut butter and crab apple jelly sandwich, anyone? My parents have crab apple trees in their yard. The trees have been there ever since I was a child living there , but their function was largely ornamental. The apples were too sour generally to use. But there are various kinds of apples lumped in under the umbrella term of "crab apple." Two of their trees make a larger crab apple and those are a little less sour.
My wife's Aunt Sharon made some homemade crab apple jelly recently and she said the most difficult part of it is picking the fruit. Making the jelly is a piece of cake! She uses the recipe that comes on the Sure-Jell package, so I am just going to be lazy and link to it. Sharon, though, boils the crab apples until they are tender enough to mash with a potato masher (her husband used an electric mixer for some also). They strained them through a heavy cheese cloth overnight to get the liquid for the recipe and then Sure Gell takes it from here.
Crab apples would fall under the tradition of self-sufficient Amish type cooking. Creative Amish cooks will make homemade jelly out of anything they can get their hands on: muscadines, elderberries, huckleberries, and even Queen Anne's Lace! This crab apple jelly is a fruity, mellow jelly that is quite delicious!