In previous Halachot, we have explained that one may not squeeze a fruit on Shabbat if there are those who usually squeeze this kind of fruit for its juice. We also explained that one may indeed squeeze fruits by hand (as opposed to using a utensil to squeeze it, which is prohibited) onto a food, for instance, squeezing an orange onto a fruit salad, in a way that the juice is absorbed by the food immediately upon being squeezed, for the entire prohibition of squeezing on Shabbat applies only when separating liquid from a solid (i.e. the juice from the fruit); however, when the liquid juice transforms back into solid form immediately upon falling into the vessel, this is permissible.
Regarding squeezing lemons on Shabbat, at first glance it would seem that this should be completely forbidden, for many people around the world squeeze lemons for their juice. In fact, the primary usage of a lemon is for its juice. Although it would be permissible to squeeze a lemon by hand onto food as we have explained above, squeezing lemons onto a liquid in order to make lemonade or squeezing lemons into an empty vessel should seemingly be prohibited. However, in the times of Maran Ha’Bet Yosef, the custom in Egypt was to squeeze lemons even for the purpose of making beverages; Maran wondered about this custom, for even Torah scholars did this and no one ever raised any opposition regarding this custom. Maran thus explained the reason for this custom as being that the only time it is prohibited to squeeze a fruit for its juice on Shabbat is only when the juice is drunk by itself without mixing any other liquids into it. However, lemon juice is not usually drunk as is; rather, it is only drunk after adding water and sugar to it (or using it to season foods) and thus, there is no prohibition to squeeze lemons on Shabbat. Many Poskim have ruled this way as well as does Maran himself in his Shulchan Aruch. Nevertheless, many other Poskim contest this ruling and rule stringently.
Therefore, Maran Rabbeinu Ovadia Yosef zt”l rules that although the Halacha on this matter follows Maran Ha’Shulchan Aruch that one may even squeeze lemons on Shabbat into a liquid or an empty pitcher in order to make a beverage or salad dressing out of its juice, it is still preferable to follow the more stringent opinion regarding this matter since this is able to be done easily. This means that before one squeezes the lemon into the pitcher, one should put some sugar in it such that the lemon juice will immediately be absorbed by the sugar, for sugar is a food and not a beverage and in this way, there is no question of the prohibition of squeezing at all. Only then should one pour the water on top in order to make the lemonade. All this, however, is only a stringency, for the letter of the law dictates that one may act leniently in accordance with the opinion of Maran Ha’Shulchan Aruch. Nevertheless, one should act stringently regarding this matter whenever possible.
