TB Zevakhim 95 and 96 Basic koshering laws

We learned some basic kashering laws on TB Zevakhim 95 and 96. The rabbis ordained that bread should be parev (neither dairy or meat) lest a person accidentally transgresses by eating meat and milk together.

“§ The Gemara relates: There was a certain oven that was smeared with animal fat all over its walls and floor. Rabba bar Ahilai prohibited eating bread baked in that oven forever, and he prohibited even eating the bread with salt alone, lest one come to eat it with kutaḥ, a dish made from milk, water, salt, and bread crumbs. According to Rabba bar Ahilai, the oven will never fully eliminate the fat.

“The Gemara raises an objection to this from a baraita: With regard to baking bread, one may not knead the dough with milk, and if one nevertheless kneaded the dough with milk, all of the bread made from that dough is forbidden, because one might become accustomed to sin. As one habitually eats bread with meat, he might also eat this bread with meat and unwittingly transgress the prohibition against eating meat with milk.” (Daf 95b, Sefaria.org translation)

Earthenware cannot be koshered. One must break and once it is broken, the taste absorbed into it vanishes. “Concerning the statement in the mishna that these halakhot also apply to a vessel into which a boiling cooked dish was poured, the Gemara notes that the Sages taught in a baraita: With regard to a sin offering, the verse states: “In which it is cooked” (Leviticus 6:21). I have derived only that this applies to a vessel in which one cooked the sin offering. From where do I derive that it applies also to a vessel into which one poured a boiling cooked dish? The verse states more fully: “But the earthenware vessel in which it is cooked shall be broken.” Since the verse employs the phrase: “In which it is…shall be broken,” that teaches that if the hot meat is in the vessel, whether cooked or poured into the vessel, these halakhot apply to it, and if it is an earthenware vessel it must be broken.” (Daf 95b, Sefaria.org translation)

A metal oven is koshered by heating white hot (libun- לִיבּוּן) in inside. “Rav construes that ruling of the baraita, according to which the fat can be burned out of the oven, as referring to an oven fashioned of metal, which cleanses the fat when kindled. ” (Daf 95b, Sefaria.org translation)

A pot is koshered by cleaning it and boiling water hag’alah-הגעלה) in to purge the absorbed taste. “With regard to a pot in which one cooked meat, one may not cook milk in it; and if one cooked milk in it, the meat absorbed in the pot renders the milk forbidden if it imparts flavor to it. Similarly, if one cooked teruma in a pot, one may not cook non-sacred food in it; and if one cooked non-sacred food in it, the absorbed teruma renders the mixture sacred if it imparts flavor to it. Therefore, a pot requires purging with boiling liquid in order to expel the flavor of teruma from it.” (Daf 96b, Sefaria.org translation)

The Mishnah on TB Zevakhim 94b requires metal vessels used in the Temple that has cooked meat of the sin offering needs scouring and rinsing (shetfa umerika- מְרִיקָה וְשְׁטִיפָה) (after koshering it by hag’alah-gg).

What’s the difference between hag’alah and shetfa umerika? The Gemara provides three different explanations.

“1. Three amora’im address the apparent inconsistency that while the Torah excludes vessels used for teruma from the halakha of scouring and rinsing, the baraita teaches that these vessels must be purged. Abaye said: When the verse excludes teruma from the halakha of scouring and rinsing, this is necessary only for that which the Master said: If one cooked in only part of the vessel, the entire vessel requires scouring and rinsing. By contrast, in this case, if teruma was cooked in only part of a vessel, one must perform scouring and rinsing only in the place of the cooking, and not in the whole vessel.

“2.  Rava said: When the verse excludes teruma from the halakha of scouring and rinsing, that is necessary only for that which the Master said: The verse specifies: “It shall be scoured and rinsed in water” (Leviticus 6:21), but the vessel is not to be scoured and rinsed in wine. It must be scoured and rinsed “in water,” but not in diluted wine. By contrast, in this case, i.e., the vessel in which teruma was cooked, it may be scoured and rinsed even in wine, and even in diluted wine.

“3. Rabba bar Ulla said: When the verse excludes teruma from the halakha of scouring and rinsing, this is necessary only for that which the Master said: One must perform scouring and rinsing with cold water, in addition to purging a vessel of its absorbed flavors with boiling water. By contrast, in this case, i.e., with regard to the vessel in which teruma was cooked, one may cleanse the vessel even by performing only the purging with boiling water, which removes the residue of the forbidden food, and omitting the cold water processes entirely.

“The Gemara asks: This works out well according to the one who says that scouring and rinsing are performed with cold water; but according to the one who says that scouring is done by purging with hot water, and rinsing is a different procedure performed with cold water, what can be said? According to this opinion, the verse is also referring to purging; and if the verse excludes vessels used for teruma, how does the baraita teach that such vessels much be purged? The Gemara answers: According to the opinion that differentiates scouring, which is done with boiling water, from rinsing, which is done with cold water, the Torah excludes vessels used for teruma only from the additional rinsing that the Torah requires after the scouring.” (Daf 96b, Sefaria.org translation)

 

I would be remiss to add that it is our tradition to rinse with cold water a pot we have koshered by the means of hag’alah.