An Essential Agent
‘Set In The Skin Of The Rennet Of Nevela’
(Avodah Zarah 35a)
Our daf relates to the sugya in Chullin (116a), which discusses the process of curdling cheese. But first let us present an overview of the concept of basar b’chalav – the prohibition of cooking milk and meat. Milk that is cooked in a pot used for meat would be forbidden if it absorbs the flavor of the meat from the pot. On the other hand, if it did not absorb any of the flavor, it is permitted because the minuscule amount of meat (flavor which is present, though not discernable) is nullified. R. Yochanan (Chullin 97a) says that one way of ascertaining whether the taste of the meat is present (in the milk) is by giving some to kpeila – a gentile chef – to taste. The general rule regarding bitul – nullification (supra 98a) – is the ratio of 1/60th meat to the milk, and that ratio or less renders the product nullified and thus kosher for consumption.
The Expert Rules
The Mishna in Chullin (116a) states that if one curdled cheese in the stomach of an animal, the cheese is forbidden if it absorbed some of the flavor from the animal’s stomach. If, however, we are able to ascertain through the services of a gentile chef that it did not absorb any of that flavor, the cheese is permitted.
Non-Kosher Source
Shmuel rules that the cheese produced by a gentile is prohibited because they commonly curdle it in the stomach of a nevelah (an animal that was not slaughtered in a kosher manner). Therefore, it is forbidden due to the possibility of nevelah content.
The Rishonim ask: Why is gevinas akum – cheese produced by a gentile – forbidden in all cases? Let us give it to an expert gentile chef to test.
What Is Common
Ramban (novella ad. loc.) answers that since it is common for the cheese to acquire flavor from the stomach, the Sages banned all gevinas akum, even where a kpeila determines there is no absorbed taste from the stomach. (They were concerned about all situations and they did not wish to weaken their ban.)
Beyond Flavor
Ri Migash (cited by Ramban and Ran folio 13 in the pages of the Rif) offers that even if the cheese did not absorb the flavor of the nevelah, they nevertheless forbade it because the rennet that the milk absorbs from the stomach is necessary to the production of the cheese. This is based on the rule that agents essential to the food’s production are too significant to be nullified even where no flavor is imparted.
