Stephanie Ann Farra who runs ‘World Turn’d Upside Down‘ writes: When Pehr Kalm, a Swedish-Finnish naturalist, visited Pennsylvania in the 1750s, he remarked that crab apples were plentiful but were not good for anything but making vinegar. Crab apples have a reputation of being a useless fruit and a nuisance. As Pehr Kalm suggested, I had actually intended to make vinegar out of my collection.
But I was still a little unsure of what kind of preserve I wanted to make. I was stuck between making marmalade and jelly. I ended up making jelly because more people would enjoy it.
 Wash your crab apples. (Mine were cherry size so I didn’t bother removing the stems or chopping the apples.) Place into stew pot and fill the pot with water until the crab apples are just covered. Bring to a boil and cover your pot then simmer about 30 minutes. The crab apples should have burst.
 Remove from the heat and carefully mash the crab apples with a spoon or masher. Once mashed, strain using a sieve or cheesecloth. Measure the juice. For every cup of juice add 1 cup sugar. Boil for about 30 minutes, or until the jelly sets. Strain into final containers.