Halachic Musings

By Rabbi Yair Hoffman

There is nothing like homemade pizza. It is fresh, delicious, cheap, and fun to make. Everyone gets involved, even the young kids, and it makes for an activity, not just a meal. It’s better than the store-bought pizza because you can modify it in whatever way you want. You can even customize each slice.

The problem is that most people have an oven that is, well, fleishig. And while it is true that a lot of people have large dairy toaster ovens, you can’t really fit the homemade pizza so well inside these countertop ovens. To get the most out of the homemade pizza experience, a large 36-inch high, 24-inch deep oven is kind of necessary. All this brings us to the three opinions about ovens, and being that Pesach is around the corner, it may be worthwhile to familiarize ourselves with some of the kashrus issues regarding ovens.

Three Opinions

– Dayan Weiss (Minchas Yitzchok Vol. V #20) and Rav Feivel Cohen, shlita, (Badei HaShulchan 92:180) are of the opinion that you really do need two separate ovens for dairy and for meat.

– Rav Moshe Feinstein (Igros Moshe YD I #40) has the middle-ground opinion that you do not need two separate ovens for dairy and for meat, but you may only cook one after the other if the second one is covered.

– The Aruch HaShulchan (YD 92:55) held the opinion that you may cook one right after the other, both without covers.

So according to the position of Dayan Weiss and Rav Feivel Cohen, one should not make homemade pizza in the regular oven and should use a toaster oven. According to Rav Moshe Feinstein, one should either wait 24 hours from when the oven was last used for meat, or self-clean it or kasher it. According to the Aruch HaShulchan, one just has to make sure that the oven is clean and one can cook the pizza right away.

Whom Do Most

People Follow?

An unofficial survey showed that the overwhelming majority of people follow Rav Moshe Feinstein’s view. Although some of our neighbors follow both the stringent view and some follow the lenient view. In short, there is divided opinion here.

This wasn’t always the case, however. It seems that a rather large percentage of our grandparents’ or great-grandparents’ generation–in the Litvish world–did follow the more lenient view. So when did the change happen?

The change seemed to happen in the Ashkenazic world because of a letter written by Rav Moshe Feinstein, zt’l, on July 15, 1954, to Rabbi Chaim Schloss, z’l, a relative of a number of residents in the Five Towns. Rabbi Schloss apparently wrote to Rav Feinstein with three rationales as to why the lenient opinion of the Aruch HaShulchan should be followed in regard to the modern 36-inch high, 24-inch deep American oven. Rav Feinstein responded with his thoughts on the matter. And the rest is history. (By the way, Rav Schloss did end up following Rav Feinstein’s view.)

In the Sefardic world, Rav Ovadiah Yoseph also rejected the Aruch HaShulchan’s position (Yabia Omer YD 5:7) to a certain degree, and the Sefardic world also began to shift toward a middle-ground position.

Zei’ah–The Underlying Issue

The underlying halachic issue is zei’ah. Zei’ah is best defined as a hot steam that emanates from an item that is cooking. And this steam is considered as if it were the essence of the item itself. “Zei’ah k’mamash.”

Is it a scientific principle wherein the actual taste is conveyed? The sources from which the halachic authorities derive the principle indicate that it is not. Rather, it seems that it is a halachic-legal principle, since it is also applied to someone who sweats after consuming impure water. This is in consonance with the words of the Vilna Gaon (OC 451:14) where he states that the prohibition is derived from the notion of tumah.

There is a debate as to whether the idea of the steam being like the essence of the item itself is a Biblical notion or a rabbinical notion. The Maharshag (Vol. II #56:5) rules that it is rabbinic, as does the Pnei Yehoshua (Kiddushin 36b, in the endnotes). The Chacham Tzvi (Responsa #20) indicates that the notion is Biblical. The majority of poskim, however, do agree with the former opinions that it is only rabbinic.

It is fascinating to note that the Talmud (Pesachim 76b) records an explicit argument between Levi and Rava concerning the kashrus repercussions of something called reicha–aroma, but it only discusses the notion of zei’ah peripherally. It is cited in a Mishnah in the second chapter of Machshirin. The Mishnah there states that the steam of a ritually unclean bathhouse transfers its tumah (unclean spiritual status) to the house itself. There is no direct mention of zei’ah in terms of kashrus in the Gemara at all.

Nonetheless, the Rosh, in a responsa (20:26) cites zei’ah as the underlying issue in regard to a pan of milk placed under a pot of meat in an oven. Based upon this responsa of the Rosh, the Tur and Shulchan Aruch (YD 92:8), rule that the zei’ah causes the pot of meat to become forbidden. The Ramah (in YD 108:10) further writes in regard to zei’ah, “If one baked forbidden food with permitted food or bread under the same pan as meat, it is forbidden to eat it with milk. But if it was done one after the other, there is no concern, unless the pan got steamed by both of them; it is forbidden even one after the other, if both were uncovered.”

The exact meaning of this comment of the Ramah has been debated for close to 500 years, probably since the day it was written.

What Items

Produce Zei’ah?

Some authorities, such as the Pri Magadim (cited in the Pischei Teshuvah 92:6), write that only liquids produce zei’ah, but foods that are not liquids do not produce zei’ah. This is also the indication of the language of the Rambam (Hilchos Tumas Mashkin 7:4) as well as the fact that in the Shulchan Aruch there is very little indication of zei’ah coming from solid food. Others disagree and write that solid foods also produce at least some amount of zei’ah, (the Sadigurah Rebbe, Yad Yehudah 92:53; and the Munkatcher Rebbe, 92:164). Indeed, the Shoel U’meishiv (mahadurah V #4) writes that this leniency cannot be relied upon. Rav Moshe Feinstein writes that we are unsure exactly what solid foods have enough liquid to produce zei’ah, so we should be stringent whenever we observe steam rising out of a solid food.

Why Is The Aruch HaShulchan Lenient?

What are the Aruch HaShulchan’s rationales to be lenient? The Aruch HaShulchan distinguishes between zei’ah that is in an enclosed area and zei’ah that emanates from an open area. He also writes that there is a principle that something boiling hot cannot be absorbing zei’ah. Rabbi Chaim Schloss adds three further arguments to support the Aruch HaShulchan’s position.

In Rav Feinstein’s response to Rabbi Schloss, he states that he thought all three of his arguments were rather weak. In his first argument, Rabbi Schloss noted the far distance between the pot and the walls of the modern range. Rav Feinstein cited views that even if the upper roof was hot it is still problematic. Rabbi Schloss suggested that the fact that the modern ranges vent on the side is a reason to be lenient too. Rav Feinstein rejects this angle as well, by citing opinions that it will not even help for aromas, much less the issue of zei’ah. The third assumption of Rabbi Schloss is that if one doesn’t see any physical indication of the zei’ah, there is room to assume that it dissipated. Rav Feinstein writes that the main concern is the bliya–the absorption, and not any physical remnant.

Another problem with the Aruch HaShulchan’s position that, curiously, Rav Feinstein does not raise, is that the Bach (New Responsa #24) had previously discussed this distinction and concluded that it was still forbidden. Rabbi Akiva Eiger (in his comments to YD 92:8) clearly indicates that both the Ramah and the Terumas HaDeshen would hold that zei’ah applies even in open places.

Why Is The Third Position Stringent?

The reasons for the position that kashering the oven is ineffective is that most of our ovens today are made with an enamel (a type of porcelain) coating over the metal. They question whether this can be kashered at all, since enamel may have clay or sand in it. There is also an issue as to whether a self-cleaning cycle is considered to be a red-hot kashering (libun gamur).

Common Practice

As mentioned earlier, the overwhelming common practice is to follow the view of Rav Feinstein and allow the use of the oven after waiting 24 hours or after kashering it. Of course, on Pesach, we do not rely on the waiting of 24 hours alone and we do require a full kashering. Significantly, Rav Feinstein himself demands a full libun gamur when kashering for Pesach and is not satisfied with the custom of cleaning and then merely leaving the oven on its highest temperature for longer than one has ever cooked items.

In regard to any kashrus issues, one must always ask one’s rabbi. But until Pesach, enjoy the homemade pizza. v

The author can be reached at Yairhoffman2@gmail.com.

Previous articleFeiglin’s Night
Next articleA Communal Apology


Please enter your comment!
Please enter your name here