Question: May you use the same drinking glasses for both milk and meat?
Short Answer: There is certainly room to be lenient and use the same drinking glasses for both milk and meat. However, Rav Moshe Sternbuch shlita rules that it is noble to be strict.
I. Drinking Glasses on Pesach
The Shulchan Aruch (Orach Chayim 451:26) writes that one may use chametz drinking glasses on Pesach as long as you rinse the cups (to remove any actual chametz). We are not concerned that chametz became absorbed in the glass when used with hot chametz liquids or foods, as glass does not absorb.
The Rama (ibid) disagrees. He notes that the minhag Ashkenaz is not to use chametz drinking glasses on Pesach. These cups may not even be kashered through hag’alah (i.e., purging), as this process does not work on glass.
Rav Moshe Sternbuch shlita (T’shuvos V’Hanhagos 1:432) rules, based on this Rama, that those who follow minhag Ashkenaz should have separate drinking glasses for milk and meat, as the cup will absorb hot milk and this absorbed milk will enter the cup when using it with a meat meal. This is a violation of Basar B’Chalav – mixing, cooking, or eating milk and meat together. Notably, this assumes that we rule that a k’li sheini (i.e., a cup that holds hot liquids that were poured from a k’li rishon, a k’li that has been heated on a fire) may still absorb its contents when very hot.
II. A Lenient Approach
Rav Sternbuch, however, then backtracks and provides a handful of reasons to rule leniently. First, the K’neses HaG’dolah (on the Tur 451) limits the Rama’s stringency to Pesach. By other laws, including Basar B’Chalav, one may simply rinse the cup after milk and use it with meat. This is the opinion of the P’ri M’gadim, as well, although he does note that we are only lenient in cases of large financial loss. Second, we are particularly stringent by chametz because even a small piece of actual chametz is asur. By other isurim, including Basar B’Chalav, a small piece is bateil. Third, here we are only discussing a k’li sheini, as well as an isur d’Rabbanan, as this is not the normal way to “cook” milk and meat together. Fourth, often the drink is not very hot when used with the meat meal. Fifth, at best, it is “nat bar nat” (it is not direct mixing of milk and meat by the taste or byproduct of milk mixing with the taste or byproduct of meat).
Accordingly, Rav Sternbuch notes that many places are lenient, including in Lita, and do not designate separate drinking glasses for meat and milk.
III. The Strict Outcome
Nevertheless, Rav Sternbuch explains that many places are strict on this issue and have separate drinking glasses for meat and milk. They reason that sometimes the liquid is still very hot when drunk with meat. Also, it is not always nat bar nat, as sometimes there is an actual piece of meat stuck between your teeth when you drink from the cup. Moreover, the Vilna Gaon rules like the Rama, that drinking glasses cannot have hag’alah by all isurim, and not just chametz on Pesach.
IV. The Conclusion
There is certainly room to be lenient. However, Rav Sternbuch rules that it is noble to be strict. This is the ruling of the Maharam Schick (Yoreh Dei’ah 141) as well. Indeed, it is minhag Yisrael to be strict with respect to Basar B’Chalav, especially where there is no large financial loss.
Further, because it is likely that one can get mixed up between drinking glasses and other materials, such as Duralex, which did not exist in earlier times and thus has no precedent with respect to absorption laws, one should be strict.
Next Week’s Topic: May you add butter to a potato baked with meat dishes (that were not used with meat in the previous 24 hours)?