Can i kasher porcelain hametz dishes for Pessach Rabbanit Surale Rosen

The Hakham Zvi (siman 75) permitted food cooked on Pesach in a hametz pot which had not been used in two years. To support his position, he cited the case of forbidden wine which was removed from a casket, and after 12 months, the owner wanted to fill the casket with kosher wine. He explains that “… the essence of the wine which was solidified on the sides of the casket after 12 months is permitted – since the moisture of the wine is gone, and is no different than the dust of the earth.” He adds: “If it is said regarding prohibited food itself that after 12 months there is no moisture and it is considered like the dust of the earth – all the more so this should be true regarding something prohibited which is absorbed in the dishes, which has no real substance.”

In other words, even if a small amount of forbidden wine remained in the casket (actual, visible wine – not just the absorbed flavor), after 12 months the casket would be dry and the wine would have no moisture. If this is true, then certainly in a case where the concern is not the actual prohibition, but only the absorbed flavor, it would be considered ‘as the dust of the earth’ (no concern at all) after so long. Therefore, there is no need to kosher the dish at all.

Since your question is dishes that have not been used in 40 years, the Hakham Zvi would likely permit their use on Pesach without hagala (pouring boiling water).

However, the Magen Avraham (Orah Haim 509:11) addresses the matter of hagala with regard to converting dairy dishes to meat (and vice versa), and states: “… it is customary to prohibit this, and it is brought in the name of the gaon R. Binyamin of Posin, that he learned from R. Jaffe the reason behind the custom: if he does so, he will only own one dish, which he will kosher through hagala every time he wants to use it – and this is prohibited because he is likely to make a mistake.”

In other words, according to the Magen Avraham it is permissible to convert dishes from dairy to meat (and vice versa), but this may create a situation in which people will only keep one set of dishes for dairy and meat, which is a recipe for mistakes – and therefore the custom is to prohibit koshering.

The Igrot Moshe (Yoreh De’ah 1:43) writes that the prohibition to convert meat dishes to dairy (and vice versa) is specific to the owner of the dishes, since this may lead to mistakes; however, there is no prohibition to do so in the case of others who receive or purchase the dishes. In the case of transfer of ownership the dishes may be converted once (at the time of purchase/receipt) from meat to dairy or dairy to meat by the new owners.

Moshe Feinstein adds that the prohibition cited in the Magen Avraham does not apply to dishes that were not used for 12 months, since there is no longer a concern regarding absorbed flavor.

Is the custom of prohibiting conversion of dishes from meat to dairy also correct regarding Pesach?

The Hatam Sofer (vol. II, Yoreh De’ah 110) cites the Magen Avraham above and explains that his stringency does not apply to koshering dishes for Pesach, which in this case may be converted from meat to milk, and vice versa, as well as for use on Pesach. He explains the reason for leniency in this case: “this is not prevalent except in the case of koshering for Pesach, when I permit converting the dishes however one wishes, from meat to dairy and the reverse – since the primary purpose of the koshering was not to convert meat to dairy, but rather to be rid of the hametz status, there is no concern regarding what the Magen Avraham wrote in the Laws of Yom Tov.”

The Hatam Sofer explains that since in this instance the primary intent of koshering is not converting meat to dairy, but rather koshering for Pesach – the Magen Avraham’s concern is not relevant. Regardless, on Pesach as well as the rest of the year one should maintain separate sets of meat and dairy dishes even after they have been koshered.

Can ceramic/porcelain dishes even be koshered?

The Tur (Yoreh De’ah, hilkhot hekhsher ve-tevilat kelim 121) cites Ba’al ha-Itur: “Even a ceramic dish, [such as in the case of] a pot which was not used in the last 24 hours – since this is only a rabbinic prohibition, one may suffice with hagala three times. And he cited the Yerushalmi as proof.”

According to this position, since the prohibition of absorbed flavor in dishes which were not used in the last 24 hours is rabbinic in nature, even ceramic dishes may be koshered – although he requires a triple hagala instead of just a single time.

Ovadia Yosef (Resp. Yabia Omer, part I – Yoreh De’ah 6) also cites the Ba’al ha-Itur, but is lenient only in the case of extreme financial loss: “the conclusion of the law is that there is room to be lenient in the case of significant financial loss, and permit to kosher a ceramic dish which was not used in the last 24 hours, even if it absorbed something that is prohibited by Torah law; this is done by hagala of the dish three times in sequence.”

The Igrot Moshe (ibid.) also rules leniently in the case of significant financial loss, and explains that in these circumstances we maintain the position that “porcelain dishes do not absorb, and are permitted altogether, just like glass which is smooth (as brought by Yad Ephraim 120 in the name of Sheilat Ya’avetz, in the name of his father).” Although some poskim disagree (e.g. Pri Megadim 103) there is a significant number of lenient poskim who can be relied upon. Furthermore, the position of Ba’al ha-Itur that dishes which were not used in the last 24 hours can be koshered by performing hagala three times – a position which is also cited by the Tur (121), can also be relied upon in this case.

Feinstein concludes that the dishes may be koshered by hagala – koshering in boiling water three times in sequence, and while hagala should not really be required after so many years, R. Feinstein rules that one should do hagala nonetheless.