If a fly or other insect falls into a bowl of soup or into a beverage on Shabbat, is it permissible to remove it from the bowl or cup?
The Maharitatz (Rabbi Yom Tob Sahalon, Safed, 1559-1638) was of the opinion that "En Berera Be’lah," which means that the restrictions of Borer do not apply to liquids. In his view, if one wishes to remove a solid substance from a liquid, this is entirely permissible on Shabbat, as this does not constitute "separating" with respect to the prohibition of Borer. The Maharitatz contended (listen to audio recording for precise citation) that the normal way of separating a solid article from a liquid is with a filter or strainer, and not by hand, and thus removing it by hand does not fall under the restrictions of Borer. He writes that just as one does not normally separate different solid substances from one another with a strainer, similarly, one does not separate a solid from a liquid by hand, and thus doing so does not meet the Halachic definition of Borer. According to the Maharitatz, then, it would be entirely permissible to remove a fly or other insect from soup or a beverage.
The position of the Maharitatz is cited in the Be’er Heteb (Orah Haim 319:2; listen to audio recording for precise citation), and this was also the view of the Mahari Abulafia. The Hida (Rav Haim Yosef David Azulai, 1724-1807), in his Shiyureh Beracha, likewise supported the view of the Maharitatz. However, the Be’ur Halacha (Rav Yisrael Meir Kagan of Radin, 1839-1933) cites other Halachic authorities, including the Taz (Rabbi David Halevi Segal, Poland, 1586-1667), who disagreed, and maintained that the laws of Borer apply to removing a solid object from liquid. According to this view, it would be forbidden to remove an insect from liquid on Shabbat.
Rabbi Moshe Halevi (Israel, 1961-2001), in his Menuhat Ahaba (chapter 7), writes that although Halacha follows the lenient position of the Maharitatz, nevertheless, it is preferable to satisfy both views by removing some liquid together with the fly. The prohibition of Borer forbids removing Pesolet (an undesirable substance) from Ochel (a desirable substance), and thus if one removes both the fly and some of the beverage, he does not perform an act of Borer at all, as he removes both Pesolet and Ochel. Given the ease of removing some liquid together with the fly, one should utilize this option in order to satisfy all opinions, rather than relying on the lenient ruling of the Maharitatz. Rabbi Moshe Halevi adds that since removing the fly with some liquid does not constitute Borer at all, none of the conditions for allowing Borer apply. As such, it would be permissible to remove a fly from a liquid even if one plans on drinking the liquid only later in the day, and not immediately, as long as he removes some liquid along with the fly.
In his work Tefila Le’Moshe, Rabbi Moshe Halevi addresses a slightly different case, where there is a layer of solid curd on top of milk, or a layer of fat on top of soup, and one wants only the liquid, without the curd or the fat. In this instance, he writes, one may rely on the Maharitatz’s ruling and remove the solid substance by itself, without also removing some liquid. He writes that there is greater room for leniency in this situation because, unlike in the case of the fly, both substances are edible food. Since the layer of fat on the soup is perfectly edible and many people eat it together with the soup, it cannot be definitively classified as "Pesolet." This allows us greater room for leniency, and thus one may remove the layer of fat (or the curd, in the case of milk), in accordance with the position of the Maharitatz, and does not have to also remove some of the soup. However, Rabbi Moshe Halevi adds, in this case one may remove the fat only right before eating, and one should not remove it in preparation for later on during Shabbat.
Summary: If a fly or other insect is found in a cup of beverage or bowl of soup, one should remove it together with some of the liquid. If there is a layer of fat on the surface of one’s soup, and he does not want to eat the fat, he may remove it even without removing some soup, as long as he plans on eating the soup immediately.
