Answer: The Gemara in Masechet Chullin (105a) states: “Mor Ukva said: When my father would eat meat, he would not eat cheese until the next day. Regarding myself, however, within the same meal I do not eat meat and then cheese, but I would eat cheese during the next meal.” The Rif writes that we learn from here that one may eat cheese after meat only after having waited the amount of time that is between one meal and the next. (We shall discuss with the Gemara’s wording in the next Halacha, G-d-willing.)
How Much One Must Wait Between Eating Meat and Dairy
The Rishonim disagree regarding exactly how much time one must wait. Rabbeinu Tam is of the opinion that one may eat cheese immediately after eating meat as long as one has washed out one’s mouth and hands. Based on this, Mor Ukva who would wait from one meal to the next was acting stringently about which he exclaimed that he did not act as stringently as his father. Nevertheless, this wait is not a halachic requirement. However, most Rishonim, including the Rif, Rambam, and others, disagree with Rabbeinu Tam’s opinion. They understand that when Mor Ukva waited the amount of time “between one meal and the next,” this was indeed a halachic requirement to which he exclaimed that he did not act as stringently as his father who would wait twenty-four hours. Indeed, Maran Ha’Shulchan Aruch rules likewise that halachically speaking, one must wait the amount of time that is “between one meal and the next.”
What is the amount of time “between one meal and the next” that one is required wait? The Tosafot write that there is no actual time limit and as long as one has concluded one’s meal, such as by clearing the table, one may eat dairy foods after meat.
Nevertheless, most Rishonim agree that one must wait six hours between eating meat and dairy foods, for this is the amount of time “between one meal and the next” that Mor Ukva was speaking about. This is indeed the opinion of the Rambam and Maran Ha’Shulchan Aruch in that one must wait six hours. The Rama writes that this is indeed the correct opinion to follow although there are dissenting views. Although there are certain Ashkenazi communities who act leniently and wait less than six hours, Maran Ha’Chida writes that in our communities, the established custom is for everyone to wait six hours. The Maharshal (Hagaon Rabbeinu Shlomo Luria, one of the greatest Ashkenazi Poskim who lived in the same generation as Maran Ha’Bet Yosef) writes that even according to the Ashkenazi custom, anyone who has a “scent of Torah” within him should wait six hours. The Sefer Aruch Ha’Shulchan (authored by Hagaon Harav Yechiel Michel Epstein zt”l who lived over one-hundred years ago) writes that nowadays, the prevalent custom among most Ashkenazim as well is to wait six hours and one should not change this, G-d-forbid.
The Reason to Wait between Eating Meat and Dairy Foods
The reason why eating cheese after meat is prohibited is because meat gets stuck in between the teeth and we are concerned that when one eats cheese, the meat caught in between one’s teeth will become dislodged thereby causing one to be eating meat and cheese together. This is indeed the Rambam’s opinion. On the other hand, Rashi and the Rosh explain that the reason is because meat gives off a taste in one’s mouth for a long time. Halachically speaking, we follow both opinions and after six hours, one may eat cheese. Even according to the opinion of the Rambam who is concerned for meat getting stuck in one’s teeth, after six hours, the meat is considered digested and poses no concern anymore. Nevertheless, if one is aware of a piece of meat stuck in one’s teeth, one must remove it even after six hours have passed.