One of the prohibited
melachos on Shabbos is
borer, separating. Thus, if two things are mixed or mingled, you may not separate one of them from the mixture. However, if it is done in the manner of eating (
derech achila), it’s considered eating and not
borer.
To qualify as
derech achila, it must meet these three conditions: (1) You take the item you want from the ones you don’t want; (2) without a special sorting device; (3) close to the time when you wish to eat or use it. Taking away the bad, on the other hand, is considered fixing the food and constitutes a
melacha.
Although peeling entails removing undesired from desired (seemingly
borer),
halacha1 permits peeling fruit vegetables or even the skin from fish on Shabbos for two reasons:
- (1) Since it is impossible to reach the edible part of the fruit without peeling, it is not considered an act of borerbut rather a normal part of eating (derech achila).2
- (2) The Alter Rebbe rules that whenever one selects one food from another, the one that remains in the hand is the selected one.3For example, pouring floating dirt from liquid in a cup is not borersince it is the desired food - the liquid - which remains in his hand. Likewise, peeling is considered like selecting the desired food from the undesired peels, since the food remains in one's hand.4
Regardless, using a peeler would be forbidden since even when removing the desired from the undesired, one may not use a special selecting utensil (
kli shemyuchad livror). According to the permission of
derech achila, using a tool doesn't qualify. Likewise, one can only peel soon before the meal (about half an hour) - both because of the laws
borer and because peeling much earlier cannot be considered part of eating.
5
What about using a peeler to peel apples and cucumbers which have edible peels? Some
acharonim hold that edible peels are part of the fruit and aren't essentially waste (
psoles) and using a peeler would be permissible,
6 while others argue that nonetheless the person who is peeling doesn't want them.
7 The matter is unresolved by contemporary
poskim and it is advisable to refrain
.8
On Yom Tov it is permissible to practice
borer even with a selecting tool (provided that it's for Yom Tov use
9 and better when freshly peeled
10). Thus, on Yom Tov all opinions agree that one may use a peeler.
11