OU KASHRUT RABBI EZRA FRIEDMAN PAGE BY Director, The Gustave & Carol Jacobs Center for Kashrut Education
Temperature for Kashering (continued)
O
ur Sages (Avodah Zara 75b) taught an essential rule regarding kashering utensils, kebol’o kach polto, meaning “the way it is absorbed is the way it is released.” This rule relates to the method of kashering but not the temperature. Regarding hag’alah (kashering with hot water), early authorities note that the water must be boiling hot. The OU ideally requires a temperature of 212°F. How� ever, Rav Belsky ruled that in certain cases a lower temperature of 190°F may be relied on. Cases of need Spray drying is a method of turning liquid into powder. The liquid is sprayed through nozzles (spray balls) in a large chamber. A spray dryer is kashered by pre-heating the chamber and then running an extended stream of near-boiling water through the spray balls. Since it is impossible to reach 212°F in this process, the OU suffices with 190°F water. This temperature is likewise sufficient when kashering other factory machinery under similar conditions. 42
TORAH TIDBITS / YITRO 5781
Based on experience in the field, the OU recommends to mashgichim and Rabbinic Field Representatives to insist on 195°F as a lowest temperature for kashering, thus allowing a 5° cushion, since thermometers are not always calibrated precisely and because there are often fluctuations. Kashering with steam Another issue involving temperature and kashering in the field is the question of steam (see Maharsham 1:92). Based on the rule kebol’o kach polto, if machinery is used to cook with hot steam there should be no problem using hot steam to kasher the machinery (Pri Chadash YD 121:15). This is the common practice when kashering a microwave. However, using steam to kasher a utensil that cooked hot liquid is a dispute amongst later authorities. Rav Moshe Feinstein (Igrot Moshe YD 1:60), in discussing this subject, is very uncertain if such a kashering process is acceptable. The OU does not allow the use of hot steam to kasher a utensil used with hot liquid. Kashering utensils used for hot oils In factories that heat and manufacture hot oils, in most cases the oils are heated to a temperature much higher than 212°F. Later authorities discuss if the hot water would need to be at that same higher temperature (which is generally not
