1) HALACHAH: ROASTING LIVER OR UDDER WITH MEAT
OPINIONS: Mereimar teaches that the Halachah is that both the liver and the udder may be roasted with meat l'Chatchilah as long as it is placed beneath the meat. The liver or udder may not be placed above the meat and roasted, but b'Di'eved one may eat the roasted food. It is clear from the Sugya and from RASHI that the Gemara is discussing roasting the meat over fire (as opposed to cooking it in a pot).
When Mereimar rules that the udder may be roasted with meat as long as it is placed beneath the meat, does he mean that it is permitted only when it was ripped open (lengthwise and widthwise) and pressed against a wall to remove the milk, or even if it was not ripped open? If he refers only to an udder that was ripped open, then why does he prohibit roasting it above the meat? An udder that was ripped open may even be cooked in a pot together with meat! If he refers even to an udder that was not ripped open, then how can it be permitted even beneath the meat? The gravy from the meat will drip onto the udder and mix with the milk inside and prohibit it! (TOSFOS DH Tusi)
(a) TOSFOS (DH Tusi) and the ROSH (8:27) write that Mereimar is discussing an udder that was ripped open in the proper manner to remove the milk. Although one is permitted to cook such an udder with meat, one is not permitted to roast it above meat, because some of the milk that remains inside after it is ripped open will drip onto the meat, and the milk on the meat will be recognizable (in which case the Isur d'Rabanan of udder-milk with meat will apply). In contrast, when the udder is cooked in a pot with meat, the udder-milk is not recognizable in the mixture, and thus the Isur d'Rabanan does not apply.
Similarly, a liver that was ripped open in the proper manner to remove the blood may be roasted only beneath meat, because some blood might drip out of the liver (TOSFOS DH Kavda). Therefore, it is prohibited l'Chatchilah to roast a liver or udder above a piece of meat, even though it was ripped open in the proper manner.
(b) The RASHBA (DH v'Asikna) explains that Mereimar is discussing a liver or udder that was not ripped open to remove its blood or milk. Why is one permitted b'Di'eved to eat the meat that was roasted beneath such an udder, if the milk falls onto the meat? The Rashba explains that it is only a small amount of milk that actually falls onto the meat; most of the milk of the udder falls into the fire. The Rabanan did not apply the Isur d'Rabanan of udder-milk with meat in a situation where the amount of udder-milk that falls onto the meat is so small. (In contrast, cooking an udder (that was not ripped open) in a pot with meat is forbidden even b'Di'eved, since all the milk of the udder becomes mixed with the meat.) Similarly, b'Di'eved one may eat the meat that was roasted beneath a liver that was not ripped open before roasting, because, as the Gemara here says, the blood of the liver slips away and does not become absorbed in the meat.
HALACHAH: The BEIS YOSEF (YD 90) cites both opinions. In the Shulchan Aruch (YD 90:4) he rules that we must be stringent like the opinion of Tosfos and the Rosh.
3) AN EARTHENWARE VESSEL THAT ABSORBED THE TASTE OF FORBIDDEN FOOD
QUESTION: The Gemara relates that when Ravin came to Eretz Yisrael, he said in the name of Rebbi Yochanan that salting is not considered like roasting, and pickling is not considered like cooking.
Abaye says that the Halachah does not follow the opinion of Ravin in the name of Rebbi Yochanan. Abaye relates that in the house of Rebbi Ami, meat was salted in a "Pincha" (an earthenware plate) in order to remove its blood, and Rebbi Ami broke the plate (because of the blood absorbed in it). Since Rebbi Ami was a student of Rebbi Yochanan, it must be that he broke the plate because he heard from Rebbi Yochanan that salting is like roasting (and since the plate was not perforated to allow the blood to flow out, as the Gemara later (113a) requires, the plate became forbidden due to the blood absorbed in it through the process of salting).
It is not clear, however, why it was necessary for Rebbi Ami to break the plate.
(a) Why did he not leave the plate unused for twenty-four hours? The forbidden taste absorbed in the plate would then be considered "Nosen Ta'am li'Fegam" (an Isur that spoils the taste of the permitted food in a mixture) and would not prohibit any food subsequently cooked in the plate.
(b) Moreover, even if he did not want to use the plate for cooking food, he could have perforated the plate and made holes in it so that it could be used for salting meat.
(c) Even if he did not want to use the plate for cooking food or for salting meat, he could have left the plate to be used only for cold foods, since cold foods do not absorb the forbidden taste in the plate.
(a) From the fact that Rebbi Ami did not simply leave the plate unused for twenty-four hours, we learn that "Nosen Ta'am li'Fegam" is forbidden l'Chatchilah. Only b'Di'eved does the Torah permit a mixture that contains a bad taste of Isur. (See RAN in Pesachim, 8a of the pages of the Rif, and BEIS YOSEF YD 95.)
(b) The earthenware plate could not be perforated, since it would break easily.
(c) From the fact that Rebbi Ami did not keep the plate to be used for cold food, we learn that any utensil that has absorbed the taste of a forbidden food may not be kept in one's possession, since one might forget and use it for hot food. The RAN writes that for this reason, Rav rules in Pesachim (30a) that earthenware dishes used for Chametz must be broken or discarded on Pesach. One is not permitted to use those dishes on Pesach for cold food because he might forget and use them with hot food as well. (See TESHUVOS HA'RADVAZ 3:1043, KAF HA'CHAYIM 95:13-14.) (D. BLOOM)
4) HALACHAH: "NOSEN TA'AM BAR NOSEN TA'AM"
QUESTION: The Gemara concludes that when fish absorbed the taste of meat by being placed on a hot plate that had been used for meat, the fish may be eaten with milk. This is because the taste of the meat in the fish is "Nosen Ta'am Bar Nosen Ta'am"; it is a secondary transfer of the original taste of the meat. The taste was transferred first from the meat to the plate, and then it was transferred from the plate to the fish. (It is "Nosen Ta'am Bar Nosen Ta'am l'Heteira," since the taste in the fish does not prohibit the fish itself. When the secondary taste of the food is prohibited, either because the mixture is prohibited or because the taste itself is one of a forbidden food, this is "Nosen Ta'am Bar Nosen Ta'am l'Isura" and is forbidden.)
Is every case of "Nosen Ta'am Bar Nosen Ta'am" (l'Heteira) permitted?
ANSWER: TOSFOS (DH Hilchesa) in the name of the RIVAN attests that RASHI prohibited eating fish with milk when the fish was cooked in a pot used previously for meat. Although such a case is a transfer of taste of "Nosen Ta'am Bar Nosen Ta'am," the process of cooking transfers the taste between the pot and the food much more than contact between a cold food and a hot plate (or a hot food and a cold plate).
This, however, is not the view of most Rishonim, including the RAMBAM (Hilchos Ma'achalos Asuros 9:23), RAN (41a of the pages of the Rif), RA'AVYAH (cited by the MORDECHAI 8:710), ROSH (8:29) and TUR in the name of Rashi.
HALACHAH: The SHULCHAN ARUCH (YD 95:1-2) writes that the Heter of "Nosen Ta'am Bar Nosen Ta'am" applies even to a food that was cooked in a pot used for meat or for milk. Thus, according to the Shulchan Aruch, one is permitted to eat fish with milk when the fish was cooked in a pot used for meat (as long as the pot was clean). However, the Rishonim (cited by the BEIS YOSEF and SHACH #3) point out that one may not cook fish in such a pot with specific intent to eat the fish with milk. Only when one decided to eat the fish with milk after it was already cooked in the pot is it permitted. This is based on the wording of the Gemara here, "fish that were placed on a plate...," implying that the fish is permitted with milk only b'Di'eved.
(The Poskim disagree about whether the Chachamim penalized one who intentionally cooks the fish in a meat in order to eat the fish with milk. Some (see PRI MEGADIM in Mishbetzos Zahav 95:4) rule that the person is penalized and is prohibited from eating the fish with milk. Others (see PRI CHADASH 95:2) rule that he may eat the fish with milk, even though he did the wrong thing by cooking it in a meat pot with intention to eat it with milk. See DARCHEI TESHUVAH 95:16, KAF HA'CHAYIM 95:5.)
The REMA, however, cites the opinion of the Rivan in the name of Rashi that a food cooked in a pot used for meat may not be eaten with milk. The Rema writes that the practice is to prohibit it l'Chatchilah, but b'Di'eved it is permitted. (For example, when the food that was cooked in a meat pot was already placed into a dairy food, one may eat the mixture.) This is the practice followed by Ashkenazim. (See also TAZ 95:3-4, SHACH 95:4-6.)