What is the correct way to remove a peel from a fruit on Shabbos? Removing a peel is considered taking bad from good. Even though this is generally forbidden, since there is no other way to get to the food, it is considered the normal way of eating. This is provided that the peel is removed prior to eating. If the peel is removed too far in advance, this is considered an act of borer and is forbidden. This rule applies even to an edible peel such as an apple. This is because by peeling it off, you turn it into “p’soles”. See Igros Moshe 4:74-8. Some poskim argue that an edible peel even when removed is not subject to the laws of borer and may therefore be peeled many hours before eating.
It should be noted that this applies only to a peel which is attached to the food. The same applies to a sticker attached to the food. However, a wrapper which merely surrounds the food but is not attached may be removed without regards to the laws of borer.

Rabbi Tzvi Aryeh Hyman, Mir Yeshiva