Apples are one of the "dirty dozen" produce items most laden with pesticides. While you can remove about 90 percent of pesticide residue with proper cleaning and preparation, the only way to ensure that an apple has no pesticides is to purchase an organic apple that you know was grown without chemical pesticides. Growing your own apples or buying from local organic farmers are the surest methods of knowing how your food is grown, but you can remove most pesticide residue from conventionally grown apples.
Run the apple under clean water, turning it as you rubbing it to remove the pesticide residue. Do not use soap on the apple, as it can leave a residue and alter the taste.
Pat the apple dry. Remove the peel with a paring knife or vegetable peeler. Most of the pesticide residue is in the peel, although the flesh still has traces of pesticide.
Bake or steam the apple to further remove the pesticide residue. A baked apple also makes a healthy desert treat when paired with cinnamon and yogurt.