1. Deriving טעמו ולא ממשו from בשר בחלב

The next Mishnah states: טיפת חלב שנפלה על החתיכה – if a drop of milk fell onto a piece of meat cooking in a pot, אם יש בה בנותן טעם באותה חתיכה אסור – if [the milk] is enough to give flavor to the piece of meat, it is prohibited. Abaye said: טעמו ולא ממשו בעלמא דאורייתא – [a prohibited food’s] flavor without its substance is Biblically prohibited. Otherwise, why would we not derive that it is prohibited מדאורייתא from בשר בחלב? Presumably, דחדוש הוא – because [the prohibition of בשר בחלב] is a novelty (in that two permitted substances become prohibited when combined, and that even the cooking itself is prohibited). But if it is a novelty, it should be prohibited even without imparting flavor, yet our Mishnah states that the milk must give flavor to the meat to prohibit it!? Rather, בשר בחלב must not be a novelty, and we can derive from it that טעמו ולא ממשו is prohibited מדאורייתא. Rava disagrees, and explains that although בשר בחלב is a novelty, דרך בשול אסרה תורה – the Torah prohibited [בשר בחלב] through cooking, which itself implies there is enough of each ingredient to impart flavor.

1. חתיכה עצמה נעשית נבילה, and אפשר לסוחטו אסור

The Mishnah taught that if a drop of milk fell onto a piece of meat in a pot and gives flavor to that piece, “it” is prohibited. Rav interprets this to mean that all the meat in the pot becomes prohibited, and explains: once the milk gave flavor to that piece of meat, חתיכה עצמה נעשית נבלה – the piece itself becomes like a neveilah (i.e., inherently prohibited), ואוסרת כל החתיכות כולן – and prohibits all the other pieces, regardless of their volume, because they are the same מין – type as the forbidden meat. He interprets the Mishnah as following Rebbe Yehudah’s opinion, that מין במינו is never בטל. When the forbidden piece of meat which had absorbed milk is cooked together with the other meat, the milk flavor is dispersed throughout the pot and may no longer be discernible in that first piece. Since Rav holds the piece itself is like a neveilah, and prohibits the other meat with its own flavor, he must hold אפשר לסוחטו אסור – even when it is possible to “squeeze out” the forbidden flavor from [the piece], it remains prohibited. This opinion is shared by Rebbe Chanina and Rebbe Yochanan, but Shmuel, Rebbe Shimon bar Rebbe, and Reish Lakish hold אפשר לסוחטו מותר.

1. Combining a חצי זית of בשר and a חצי זית of milk

The Gemara discusses: חצי זית בשר וחצי זית חלב שבשלן זה עם זה – if one cooked a half-zayis volume of meat together with a half-zayis of milk, Rav says: לוקה על אכילתו – he incurs malkus for its consumption, ואינו לוקה על בשולו – but does not incur malkus for its cooking. The Gemara objects that these two rulings appear contradictory: אי מצטרפין – if they combine for malkus for consumption, he should be liable for cooking it as well. If not, he should not be liable for its consumption!? The Gemara answers that Rav holds they do not combine for a shiur. The case one is liable for their consumption is בבא מיורה גדולה – where [the meat and milk] come from a large pot in which full measures of meat and milk were cooked together. Once all the meat and milk is prohibited as בשר בחלב, eating a half-zayis of each incurs malkus.

Levi disagrees with Rav, and says one incurs malkus for cooking (or eating) a חצי זית of meat together with a חצי זית of milk.