Peaches do not need to be peeled for jam. In fact, the peels add a wonderful texture to the jam. However, if you prefer a smoother textured jam, you can blanch the peaches first by dipping them in hot water, then cold, to stop the cooking process. This process will help loosen the skin. Another option is to leave the peach skins on and puree the jam instead. This can be done prior to canning the preserves.