Is one permitted to wash fruit on Shabbos, which is in effect removing dirt etc from the fruit?

The Shulchan Aruch [1] tells us that one is forbidden to soak karshinim [2] that are mixed with peels and other refuse in water, which action will separate the karshinim from the peels. The Mishna Berura [3] adds that it is similarly forbidden to pour water over potatoes etc in order to clean them of their soil particles.

This implies that one is forbidden to wash fruit and vegetables on Shabbos.

Many poskim want to differentiate between soaking in water and washing fruit under running water.

Rav Moshe Feinstein ztz”l [4] presents a few reasons why washing fruit is permissible. 1. When dirt covers the fruit, one may wash it off prior to eating just as one is permitted to peel garlic and onions prior to consumption.

2. In many cases people eat fruit or vegetables without washing these items and in such cases the dirt is not considered p’soles at all.

Rav Moshe concludes that perhaps only soaking in water is considered 'derech b'reira' but washing with water is not.

Did the Mishna Berura not say that it is not permitted to pour water over potatoes as well?

True, he did, and we can say that he also means that the water is being used as a separator and not as a cleaner, for example: it is forbidden to place potatoes etc inside a bowl and run water into the bowl where the water would separate between the food and the dirt. This is how the 'Ketzos HaShulchan' [5] explains the M”B, because he also understands that it is obvious that washing fruit the way we usually do is not called borer at all but rather it is compared to peeling fruit, which is permitted prior to consumption.

Rav Shlomo Zalman Auerbach ztz”l is also of the opinion that washing fruit the way we do has nothing to do with the case of the Shulchan Aruch. [6]

Undoubtedly, if it is possible to wash the fruit before Shabbos one should do so. Once washed before Shabbos and one wants to wash the fruit again on Shabbos for added cleanliness (and the fruit are still clean) one may do so.

 Other poskim [7] are not so lenient and do not differentiate between soaking and washing and therefore require that all dirty fruit should be washed before Shabbos unless it is fruit that most people would consume without washing beforehand.

Am I permitted to pour out the oil that lies atop the tuna in a can of tuna fish, or must I remove the tuna together with the oil?

We will begin with the simple case. The oil sitting atop the tuna fish is not mixed with the fish and hence its separation is not borer. Therefore one may pour out the oil that is above the tuna fish.

To pour out all the oil, or at least as much as possible is forbidden, even when performed prior to consumption, because one is pouring out the p’soles from the ochel.

The more innovative case is when one wishes to pour off surplus oil and requires some oil to remain. Rav Moshe Feinstein, [8] when asked a similar question, replied that if one wishes to pour out excess soup so that some soup will remain with vegetables it is permitted, as long as one does not pour out all the soup.

Here too, since one wants some oil to remain with the tuna, one has not really separated between the two. (Although we know that removing one stone from flour is forbidden even though other stones remain, the reason being is because a stone is an absolute p’soles whereas two types of food which we want to remain together are not labeled as p’soles unless we require their total separation).

This halacha applies itself to many cases and one must take care not to pour out juices etc from foods.

The sweater I need is in the middle of a pile of sweaters, am I permitted to remove the top ones in order to reach the sweater I need?

The Mishna Berura [9] teaches us that one may move sweaters etc out of the way in order to reach a sweater located somewhere in the middle of the pile if required for immediate use. This is true for a pile of clothes on a chair next to one’s bed when one is looking for an article of clothing somewhere in the middle. The chidush is that we do not say that when actually removing the outer laying one has already “separated” between the items and liable for Borer. On the other hand, one may not remove dirt from a mixture and say that he is merely doing so to reach the mixture, because by actually removing the dirt one is separating between p’soles and ochel.