If you like tart apples, try Granny Smith. They are usually harvested a little bit too early, so they are often very sour and very green (the ripe version has a

If you like tart apples, try Granny Smith. They are usually harvested a little bit too early, so they are often very sour and very green (the ripe version has a very slight shine of red). Their skin is thick and requires a little effort to chew. I love them.