- Kashering Dishes
The Rabbi stated that fine china dishes cannot be koshered unless immersed in boiling water. However in the case cited, the questioner stated he could not for fear of breaking the dishes. I wish to point out that china dishes are not the same as earthenware. Fine china is glazed and glaze is a thin coating of glass which has the effect of sealing the eating surface.
Porcelain, China and Fine China are basically the same. A strong, vitreous, translucent ceramic material, biscuit-fired at a low temperature, the glaze is then fired at a very high temperature. According to the Halachic authorities porcelain is treated as earthenware; it is not sealed, but is absorbent. Therefore it has the same Halachic status as earthenware which according to the actual law there is no way to kosher them. Only in a case of a great loss, and in addition the dishes were not used for 12 months, there is a possibility of being lenient for the sake of making matters easier for the repentant which is to kosher the dishes by doing Hagalah (making dishes kosher by immersion in boiling water) three times. However as noted above, it is impracticable in the case specified. Earthenware utensils that are coated with glazing have the same ruling as ordinary earthenware utensils (Shulchan Aruch Orach Chaim 451, 23). The Mishnah Berurah explains: That are coated, etc. i.e. on all sides. Although the author of the Shulchan Aruch writes in par. 26 that glass utensils do not absorb at all. In the case of the utensils discussed here, where the glass covers earthenware and was hardened with it in the furnace, it is more capable of absorbing (Mishnah Berurah 137. Rosh Pesachim Perek Kol Sha'ah, 8). Please see the sources of which most were quoted in the previous responsa. Rosh ibid. Shulchan Aruch Orach Chaim 451, 23 and Mishnah Berurah 137 & 163. Igrot Moshe Yore Deah 2, 4. Sefer Hakashrut 3, 50-51.