By Rabbi Leonard Rosenthal, Tifereth Israel Synagogue, San Diego

I was recently approached by a crestfallen congregant with a challenging problem. He kept a Kosher home and had accidentally added milk to a guest’s coffee. The coffee cup was fine china and used exclusively for meat meals. His questions: was the coffee cup now treif and if so, did he need to throw it out?

He had good reason to worry. The laws of kashrut hold that an earthenware vessel absorbs whatever hot food is put on it, and can then expel particles of that food the next time it is used. We learn this explicitly in this week’s parsha, Tzav: "This is the ritual of the purification offering...Anything that touches its flesh shall be holy...An earthen vessel in which it was boiled shall be broken; if it was boiled in a copper vessel, [the vessel] shall be scoured and rinsed in water." (Lev. 6:17-21)

Our Etz Haim Torah commentary explains: "Earthenware, being more porous than metal, absorbs particles of the flesh boiled in it. Some of the sacrificial flesh very likely would remain in the vessel. Such flesh would constitute "leftovers of the sacrifice" (notar), forbidden for consumption according to Lev. 7:15-17. If other foodstuffs were subsequently boiled in the same vessel, the forbidden sacrificial particles would contaminate the rest. To prevent this, the earthenware vessel had to be broken, because there was no way to purify it." (Etz Haim, p. 616)

The same general reasoning holds true with earthenware or porcelain today. Unlike metal, which can be kashered through boiling, or glass, which does not absorb, there appears to be no way to kasher earthenware. Once you put milk into a hot earthenware cup, it is absorbed and can then be discharged the next time hot liquid is added. The teacup was, indeed, treif.

So did I make our congregant throw out his cherished pottery?

No. A chairperson of the Conservative Movement’s Committee on Jewish Law and Standards(CJLS) has taken the position that, "Glazed pottery dishes are probably as non-porous as glass; however, it is not recommended that they be used for both milk and meat, if only to preserve the principle of separation."

Furthermore, "Porcelain dishes may be used again after not being used for a period of one year, if they are expensive and would involve a large loss of money." And even stronger: "To facilitate the change from a non-kosher to a kosher home, expensive dishes, even those that are not china, may be set aside, unused for one year and then can be considered kosher."

Although it is a not an official position of the CJLS, most conservative rabbis hold that if you allow non-kosher china to go unused for a year, it becomes kosher once again.

Our congregant was delighted when I gave him the good news. He took the treif teacup, sealed it in a plastic bag, put the date on it, and is drinking from an unmatched teacup until the day comes when the banished vessel can rejoin its brethren.

In my family we have done the same with porcelain that we have inherited from relatives that did not keep kosher, or with old china we wanted to use for Pesach. We put it aside for a year, then began using it again.

I have been approached more than once by people who are interested in observing kashrut, but are concerned with the financial loss they may occur by having to replace all of their dishes, silverware, pots, and pans, or having to give away family heirlooms. As you can see, most kitchenware (except those made out of wood) can be kashered. If you are considering keeping kosher, please do not let the potential loss of your dishes be an impediment.