Very often, the laws of mixing dairy and meat, בשר בחלב, are discussed on Shavuot. As part of our preparation for Shavuot, we will discuss aspects of the laws of dairy and meat. We will begin with a discussion of Nat Bar Nat, נ"ט בר נ"ט, the laws regarding Pareve items cooked in a meat or dairy pot.
Talmudic Background - Disagreement between Rav and Shmuel:
The Talmud (Chullin 111b) records a dispute between Rav and Shmuel regarding the following case: Hot fish was placed on a meat plate (a plate that had hot meat placed on it). The Rabbis debate whether it is permissible to subsequently place the fish with dairy. Rav rules that it is forbidden to do so, but Shmuel rules that it is permissible to do so.
Rav believes that it is forbidden to do so because the fish absorbed a meat taste. Shmuel believes it is permissible because the fish is two steps removed from the meat -- first the meat is absorbed in the plate and then the meat in the plate is transferred to the fish. The connection between the fish and the meat is too remote for a mixture of fish and dairy to be considered a prohibited mixture of meat and dairy. This situation is referred to by the Talmud as Nat Bar Nat - נתינת טעם בר נתינת טעם - a second generation transfer of taste - literally, the imparting of taste the son of imparting of taste. After citing a number of incidents which support the view of Shmuel, the Gemara concludes that the Halacha follows the view of Shmuel (for an analysis of the reasoning of this rule, see Tosafot on Zevachim 69a s.v. v'im, and see the Taz Yoreh Deah 59:3 for an explanation of why this case is not a violation of the rule that one is forbidden to eat fish and meat).
Rishonim - 3 opinions
Rishonim debate the scope of the applicability of the rule of Nat Bar Nat. The Rivan (cited in Tosafot Chulin 111b s.v. hilchata) cites the opinion of his great father-in-law, Rashi, who limits the applicability of Nat Bar Nat. He relates that Rashi believed that only fish placed on a meat plate is considered Nat Bar Nat, since only a small amount of meat taste is absorbed into the fish. continued on next pageHowever, if fish is cooked in a meat pot, then the fish is not Pareve even according to Shmuel. This is because the fish has absorbed a great deal of "meat taste" from the meat pot. Rivan relates that once someone asked Rashi if an egg that was cooked in a dairy pot can be cooked with meat, and Rashi replied in the negative.
Tosafot, however, note that a different impression is gleaned from Rashi's (s.v. Nat Bar Nat) commentary to the Gemara Chulin 111b. Rashi explains that the fish attains the status of being "meaty" only if it is cooked with actual meat. Rashi clearly implies that if the fish is only cooked in a meat pot, then the fish remains Pareve. Indeed, Rashi's grandson, Rabbeinu Tam, and his great-grandson, the Ri, both believe that the Nat Bar Nat rule applies, so that even if the Pareve item was cooked in a meat or dairy pot, the cooked item remains Pareve (see Haghaot Ashri, Chulin 8:92).
The Rosh (Chulin 8:03) cites the Sefer HaTruma who adopts a middle position. He believes that a Pareve item roasted in a meat or dairy pot is no longer Pareve. However, if the Pareve item is cooked in a meat or dairy pot it is still considered Pareve. The cooking case is different because the Pareve is three steps removed from the meat. First, the meat was absorbed into the pot, subsequently the taste of the meat is imparted to the water the Pareve item is being cooked in, and only then to the Pareve item. Indeed, Tosafot (Avoda Zara 67a s.v. Bat Yoma) asserts that all agree that a Pareve item cooked in a meat or dairy pot remains Pareve if it is three steps removed.
Rav Yosef Karo, in his Beit Yoseph (chapter 59 s.v. dagim) cites many Rishonim (including Rashba, Ran, Ravya) who subscribe to the most lenient opinion, that Pareve food cooked or even roasted in a meat or dairy pot is still considered Pareve. Indeed, in the Shulchan Aruch (Yoreh Deah 59:2), Rav Karo rules according to the most lenient opinion that Nat Bar Nat applies even to Pareve food roasted in a meat or dairy pot. The Rema then notes that the Ashkenazi practice is to initially (lechatchila) be concerned with the strict opinion. That means, for instance, that a Pareve item cooked (or roasted) in a meat pot should not be eaten with dairy foods. If, however, the Pareve food happened to have been mixed with dairy food (i.e. bedieved), the Rema writes that the Ashkenazi practice is to follow the lenient view.
The Rema seems to permit (bedieved) even Pareve food, roasted in a meat pot and subsequently mixed with dairy, to be eaten. The Shach (59:4), however, cites the opinion of the Maharshal that if a Pareve item was roasted in a meat utensil and then mixed with dairy, it cannot be eaten. This opinion follows the aforementioned opinion of the Sefer HaTruma. However, the Aruch HaShulchan (59:21) and Chochmat Adam (84:1) adopt the ruling of Rema as normative, even though the Shach is regarded as an extraordinarily eminent authority. The Rema's opinion is followed (most likely) since it is based on the actual practice of Ashkenazic Jewry.
Waiting Between Meat and Dairy in the Case of Nat Bar Nat
Rema (98:3) rules that one is not required to wait (six/three hours) after consuming Pareve food cooked in a meat pot. This is permitted because (see Igrot Moshe Y.D 2:62) the reason we wait between meat and dairy is that either some meat remains in one's teeth or that the taste of meat remains in one's mouth after eating meat. Obviously, these two reasons do not apply to Pareve items cooked in a meat pot, and accordingly, there is no need to wait six or three hours before consuming dairy foods.
The Darkei Teshuva (99:34) cites a responsum of Rav Shlomo Kluger where he permits one to eat Pareve items cooked in a dairy pot within six/three hours after consuming meat. Rav Kluger notes that common practice is to be lenient regarding this question.
Eino Ben Yomo - Pot not Used for Twenty Four Hours
Rema notes that Ashkenazic practice is to treat a Pareve item cooked in a meat or dairy pot that was unused during the previous twenty four hours (Eino Ben Yomo), as Pareve. For instance, if one cooked potato in a meat pot that had not been used in the previous twenty four hours, one may eat the potato with sour cream. The reason for this is that Chazal believe (see Avoda Zarah, 57b) that a taste absorbed in a utensil turns rancid after remaining in the pot for more than twenty four hours. Hence, the pot will subsequently emit a bad taste from the food it previously absorbed (נותן טעם לפגם). If the taste emitted is bad, it does not render the food it enters as forbidden. In our example, the meat taste expelled into the potato was bad and hence does not render the potato as "meaty", even according to the strict opinion. The Chochmat Adam (84:2) notes, however, that one should not initially cook a Pareve item in a meat or dairy pot, even if it has not been used in the past twenty four hours, even if one plans to eat with a food type opposite to the type of the pot it was cooked in.
We have presented the basic rules of Nat Bar Nat. However, since there are many more details and exceptions to these rules, one should consult his Rabbi if he is confronted with a situation of Nat Bar Nat.