CCAR RESPONSA
American Reform Responsa
51. Use of Pyrex Dishes for Meat and Milk
(Vol. XXIX, 1919, pp. 78-79) Not knowing what Pyrex is, I must be guided by the information that it is glass, and on this presumption give the following information in reply to a question submitted to me. The Mosaic law (Exodus 23:19, 34:26 and Deuteronomy 14:21) says: “Thou shalt not seethe a kid in its mother’s milk.” This the Rabbinical law explains to prohibit the mixture of any milk or milk product with the meat of animals and fowls (Shulchan Aruch, Yoreh De-a 87.13). I am always quoting the latest standard authorities on Rabbinical law. This prohibition is extended to the use of vessels, so that a vessel used for milk must not be used for meat and vice versa (Yoreh De-a 93.1). “Glass vessels, even when used for permanent preservation of food, including hot food, require no purification (if, e.g., they were used for boiling milk and subsequently are to be used for boiling meat), for they do not absorb anything of their contents, and mere rinsing before using them again is sufficient” (Joseph Caro, Orach Chayim, 451.27). The glossarist Moses Isserles adds: “Some authorities take a rigorous view and declare that even washing the vessels in hot water does not help. This is the practice in Germany and Poland.” The filossarist David Halevi, author of Turei Zahav, adds: This rigorous view is based on the assumption that glassware is equal to earthen ware. If, however, the glass dishes [usually used for milk or meat] had been accidentally used [for the other kind], there is certainly no prohibition” (ibid., 30). “Earthen vessels used for the permanent preservation of prohibited wine are, according to some authorities, not to be used [for kosher food], but all authorities are unanimous in the opinion that this prohibition does not include glass vessels” (Yoreh De-a 135.8). The glossarists Shabbetai Kohen (Shak, ibid., 23) and David Halevi (Turei Zahav, ibid., 11) give as a reason for this exception the fact that glass vessels have a smooth surface and do not absorb anything of their contents. These quotations should suffice to prove that Pyrex, presuming that it is glassware, may be used for both milk and meat dishes and would therefore mean both a convenience and a saving in kosher households. Inspection of the article would seem necessary to convince the man who gives the decision that Pyrex is what it is represented to be. Ritualistic questions are to be submitted to an authorized rabbi. There is, however, no guarantee that a decision given by one rabbi would be recognized by others, for Judaism has no ecclesiastic authority in an hierarchical sense. New York had last year a heated controversy between two sections of Orthodox rabbis, led by R. Wolf Margolis, on the one hand, and Moses Zebulun Margolis on the other. It may be presumed, however, that if a few recognized authorities would subscribe to this opinion, it would be respected by the vast majority of observant Jews. It ought to be translated into Hebrew and Yiddish, for a Hebrew endorsement (Hechsher) put on the goods would, to most people, be a sufficient guarantee.G. Deutsch
If needed, please consult Abbreviations used in CCAR Responsa.