Monique Susskind Goldberg
Koshering dishes for Passover
With Passover closing in: I understood that according to Orthodox interpretation, it is impossible to make porcelain kosher for Passover. Is this also the case in the Conservative interpretation? Which dishes can be made kosher for Passover then and which can't? And are these the same regulations that apply if I want, for example, to turn dishes into meat-only or milk-only dishes?
Regarding kashering dishes for Pesah, see my answer about kashering old dishes on this site:
China of ceramic and porcelain are considered earthenware, and according to halakha cannot be koshered. Even with the glass glaze, the dish is considered porous (Shulhan Arukh Orah Hayim 451:1, 22-23).
However, there are important contemporary deciders like Moshe Feinstein (Igrot Moshe Yoreh Deah, part 2, no. 46) who allow using some pieces of china after 12 months during which it was not used. The main reason is that after 12 months, the "the taste" of whatever was absorbed in the bowl has disappeared and the dish is like new (Yoreh Deah 135: 16).
The same rule applies for koshering for Passover and for changing from meat to milk dishes. Metal dishes, pots, pans and silverware can be kashered by immersing them in boiling water.
Sefardim following the view of Yosef Karo (Shulhan Arukh Orah Hayim 451:26) believe that glass dishes are not porous and thus can be used for Pesah if they are thoroughly washed. Askenazi Jews do not accept this rule.
Rabbi Monique Susskind Goldberg