Question: May one use regular lettuce sold in supermarkets which has not been inspected or grown under controlled conditions with regards to worms and other insects? What is the Halacha regarding grape leaves?
Answer: The Gemara in Masechet Pesachim (24a) states that one who consumes a worm transgresses five Torah prohibitions. Hagaon Harav Chaim Benbenisti writes in his Sefer Kenesset Ha’Gedolah (Yoreh De’ah, Chapter 84) regarding lettuce grown in his vicinity which was heavily infested with worms and had to be checked extremely carefully since the worms were very small and are the same color as the lettuce, thus appearing to be part of the actual leaf. He writes, “In the past, I would eat from the leaves of the lettuce (to fulfill the Mitzvah of eating Maror on the night of Pesach) by first checking them well; now, however, I have completely stopped eating the leaves and only eat the white stalk of the lettuce and even this is after checking it well.”
It is recorded in the book of customs of Hagaon Chatam Sofer zt”l (Hilchot Pesach, Subsection 18) that the Chatam Sofer would use lettuce in order to fulfill the Mitzvah of eating Maror during the Pesach Seder. He would appoint young Torah scholars to check the lettuce well using a magnifying glass. This was only on the first two nights of Pesach; however, during the rest of the year, lettuce was not served on his table at all.
Similarly, Hagaon Rabbeinu Yosef Haim writes in his Ben Ish Hai (Parashat Tzav, Subsection 27): “The woman in charge of the household must take great care in checking the lettuce, for it is commonly infested with worms. Indeed, the entire household depends on her regarding this matter. If she is lax regarding the checking, she will be held accountable for these transgressions and it is possible that she will be liable for more lashes than the hairs of her head, for one is liable for five sets of lashes for every worm one consumes. If the members of the household are great in number and it is difficult for her to check so much lettuce, the leaves should be removed and only the stalks should be used, for these are much more easily checked and can be used to fulfill the Mitzvah of eating Maror.”
Maran Rabbeinu Ovadia Yosef zt”l quotes all of these sources in his Responsa Yechave Da’at (Volume 1, Chapter 18).
Hagaon Harav Moshe Feinstein zt”l was asked if certain kinds of cabbage may be eaten after a regular checking for worms. He responds as follows (in his Responsa Igrot Moshe, Orach Chaim, Volume 4, Chapter 91): “Where we were in Europe, cabbage was heavily infested with worms and required very tedious checking; however, here in America, cabbage is not as infested and therefore American cabbage requires only a cursory checking. The same applies to lettuce, for we know that there are places where the lettuce is not so infested with worms. However, regarding a vegetable which is known to be very infested or in places where it is known that the cabbage and lettuce are infested with tiny green worms, one should not rely on just anyone to carry out this tedious checking.”
Nowadays, in the places where we reside, experience and testing has shown that lettuce leaves are infested with hundreds of worms. It is nearly impossible to check them well for worms. When Maran zt”l was younger, he knew of a certain household that would clean lettuce leaves well, soak them in vinegar, check them while holding them up against the sun, and then leave them for use to fulfill the Mitzvah of eating Maror. Maran zt”l took these leaves and placed them on a white tablecloth in the sun and several minutes later, the tablecloth was full of worms crawling out of the lettuce leaves.
Maran zt”l therefore ruled that it is preferable to use only the white lettuce stalks for the Mitzvah of Maror and not the green leaves. Even the stalks should not be used until one has checked them well, calmly, and thoroughly.
Nevertheless, there are countries (in South America) where they claim that the lettuce is not so heavily infested and it is possible to check it. The residents of such places should research the veracity of these claims and thus determine if they may continue eating regular lettuce.
In the past several years, the residents of Gush Katif began growing lettuce in controlled greenhouses in a way that removes all concern. By washing the leaves well in accordance with the instructions on the label, one may eat these lettuce leaves. Other companies have since opened and followed suit, in Israel as well as in the United States. It is therefore worthy for one to only purchase lettuce of this sort and not lettuce that was grown under non-controlled and non-inspected conditions.
If one wishes not to purchase such lettuce because it contains all sorts of harmful pesticides which are dangerous for consumption, one may be concerned and act stringently; however, one should still not purchase lettuce grown under non-controlled conditions, for there is great concern for worm infestation.
Regarding grape leaves, it is well-known that the sages in Aleppo, Syria banned the usage of grape leaves over one-hundred years ago because it was almost impossible to check them well for worms. Nevertheless, in the past several years, pickled and canned grape leaves manufactured from grape leaves grown under controlled conditions have entered the market under the strict supervision of various respectable Kashrut agencies and these may be used, based on the instructions of the Kashrut agency.