Does Steam Rising from a Pot Make a Product Meat, Dairy, or Non-Kosher?

The Law of Steam Rising from a Cooked Dish

It is common during cooking to pour from a bottle of oil or a spice jar into a pot of food standing on the fire. Usually, because the food is boiling, steam rises from it. We must discuss a case in which the pot contains a forbidden substance: do the oil or spices become forbidden because of the steam? Likewise, if the pot contains dairy or meat, do the oil or spices become dairy or meat?

There are two halachic issues to discuss here: 1. the law of nitzok; 2. the law of zei’ah — steam/condensation. We will explain these laws and concepts.

In the case of forbidden food — initially, pouring is prohibited because of nitzok

The Rema (Yoreh De’ah 105:3) rules: “It is forbidden to pour from a vessel containing kosher fat into a burning lamp containing chelev or forbidden fat; but after the fact, there is no concern.”

The Taz (Yoreh De’ah 105:6) explains the reason: “because the lower item prevails and connects it through nitzok.” In other words, there is a rule that when two foods are positioned one above the other, one cold and one hot, the lower one prevails and imparts taste. Therefore, if the lower one is boiling and the upper one is cold, the upper one receives taste from the lower one; whereas if the situation is the opposite — the lower one is cold and the upper one is hot — the lower one does not receive taste from the upper one.

However, all this is when there is direct contact. Here the contact is not direct, and therefore an additional law is needed: nitzok chibbur, meaning that when a liquid is being poured and touches the lower food, it is considered a connection, as though all the liquid touched the lower food.

The Shach (Yoreh De’ah 105:11) writes that the reason is the vapor rising from the lamp. The Pri Megadim (Mishbetzot Zahav 105:6) explains that there is no dispute between the Shach and the Taz; the Shach also means that it is initially forbidden because of nitzok, i.e., through the law of nitzok, the heat of the lamp containing chelev or forbidden fat rises upward to the bottle of kosher oil through the poured oil that connects them together.

Why does it not prohibit after the fact?

It is clear from the Rema that one may not pour from a vessel containing kosher food into a vessel containing hot forbidden food, because of nitzok. This law applies only initially; after the fact, if one did so, nitzok does not prohibit. The Vilna Gaon (Yoreh De’ah 105:21) explains the reason: we find the law of nitzok with regard to yayin nesech and the laws of ritual impurity and purity. Specifically in these areas, if kosher wine touched yayin nesech, it becomes prohibited even though no taste was transferred; likewise, an impure liquid that touched a pure liquid renders it impure. Therefore, in these laws nitzok is considered a connection that prohibits even after the fact, since the matter depends merely on contact. But in the laws of prohibition and permission this is not so, because the taste of the prohibition does not pass through nitzok.

It follows that according to the essential law, nitzok does not transfer taste. Nevertheless, initially, since there is a connection and heat naturally rises, it was prohibited; but after the fact, it does not prohibit.

The practical conclusion: A liquid item, such as oil, may not initially be poured into forbidden food. But spices, where there is no connection of nitzok and each grain falls on its own, are not found to be prohibited even initially. After the fact, in any case, it is permitted.

Why do steam and condensation not prohibit?

However, we must still explain why, when pouring cold kosher fat into a vessel containing burning forbidden fat, it does not become prohibited after the fact because of the vapor and steam rising from the burning lamp. After all, there is a law that steam rising from something forbidden imparts taste to permitted food that comes into contact with it.

The very law that steam rising from a cooked dish imparts taste into a vessel located above the steam originates in the responsa of the Rosh (Klal 20, siman 26), regarding a person who places in a stove [a type of ancient oven] a dairy pan with dairy food at the bottom of the stove, and above it a meat pot with meat food. The steam rises from the dairy food to the pot above it. Such steam is called in halachic terminology “zei’ah,” and the Rosh rules that this zei’ah has the status of actual milk. Therefore, when it meets the upper pot, it is treated like boiling milk that fell onto the upper pot. The Shulchan Aruch (Yoreh De’ah 92:8) rules in accordance with the Rosh.

In light of this, the question arises: why is there no problem pouring kosher oil from a bottle above a burning lamp containing fat forbidden for consumption? And why should the steam of the boiling fat not prohibit the bottle of oil even after the fact?

The distinction between a lamp and a pot above a pan

One may answer that a lamp containing chelev produces a very small amount of steam rising from the burning lamp, whereas a cooked dish in a pan in a stove produces a large amount of steam toward the upper pot.

Another distinction may be that the heat of the steam rising from the burning lamp cools down, and by the time it reaches the bottle and the upper oil, the steam no longer has the heat of yad soledet bo. It is explained in the Shulchan Aruch (Yoreh De’ah 92:8) that steam prohibits only if it is hot to the degree of yad soledet bo.

A further answer is that in the case of the lamp, one is pouring from the side into the pot, and steam prohibits only when it rises directly upward; but when it spreads to the sides, it does not prohibit, as explained in the responsa of the Bach (new responsa, part 2, siman 24) and in the responsa of the Maharsham (part 4, siman 85 and siman 119).

Practical halachah These three distinctions are correct. In order for zei’ah to prohibit after the fact, there must be a large amount of steam; the steam must remain at a temperature of yad soledet bo [one should be stringent from approximately 46–47°C]; and the steam must reach directly, not spread to the sides.

In summary: We have learned from the words of the Rema that initially one may not pour from a bottle of oil or a spice jar into a pot in which forbidden food is being cooked, because of nitzok. But after the fact, if one poured from the side or from a height, it does not become prohibited, because in that situation the steam is no longer at a temperature of yad soledet bo.

However, if one pours directly in a place where the steam is boiling hot and abundant — for example, when the lid of a pressure cooker is removed and one struggles to keep one’s hand there because of the heat of the steam, or one pours with a long bottle because one cannot put one’s hand into the heat — the bottle becomes prohibited even after the fact.

Separate bottles of oil and spices for meat and dairy

In light of the above words of the Rema, we must discuss whether one needs to keep two bottles of oil at home — one for pouring into a dairy pot and one for pouring into a meat pot. Likewise, must one designate separate spice jars for meat and dairy? Since the Rema wrote that initially one may not pour from them into a forbidden item, perhaps the same applies to meat and dairy, both because of nitzok and because of steam.

In practice, however, since the Rema’s words were said only initially and only regarding something forbidden, we have no basis to be stringent with meat and dairy, which are permitted items. There is no need for concern even if one pours oil in the morning onto dairy and in the evening onto meat. We do not find that with permitted foods one must initially be concerned because of the law of nitzok. [However, see Taz (siman 95:13) and Pri Megadim (Mishbetzot Zahav there).]

Nevertheless, one must still discuss steam: when one pours from a bottle of oil or spice containers into a boiling pot of meat or milk and steam rises from it, do the oil or spices become meat or dairy?

Indeed, as explained above, steam does not prohibit if it is not hot at the level of yad soledet bo, such as when one pours from a height or from the side.

We have learned that according to the essential law there is no need for two bottles of oil for meat and dairy when pouring from them directly into a pot, and the same applies to two spice containers, since generally one pours from the side, or even if one pours above the pot, the steam usually is not at a temperature of yad soledet bo. However, one must indeed be careful not to bring the bottle or spice jar close to direct steam in a place where it is at the heat of yad soledet bo.

A separate kettle for meat and dairy

Above, it was explained from the Rema (Yoreh De’ah 105:3) that because of the law of nitzok, one may not pour cold kosher food into hot non-kosher food. The source of the law is a Mishnah (Machshirin 5:10): one who pours pure cold liquid into impure hot liquid — the upper liquid becomes impure. They were stringent initially to apply this law also to prohibitions; however, after the fact, it prohibits only with yayin nesech and impurity, as above.

But one should consider the reverse case: if the upper liquid is hot and the lower food is cold. This is common when pouring from a boiling kettle into a cup of milk, or onto frozen meat to thaw it. Does the kettle become dairy or meat?

The Chok Yaakov (siman 451:57) and Shulchan Aruch HaRav (siman 451:59) write that even when hot is poured into cold, one should initially be stringent regarding nitzok; this is not the place to elaborate.

Accordingly, it would seemingly be forbidden initially to pour directly from a kettle into a cup of milk or onto frozen meat.

However, as stated, one may argue that the law of nitzok is found only regarding a prohibited item and not regarding permitted items. Therefore, it is permitted to pour from a hot kettle into a cup of milk that is not hot, or onto frozen meat. As for steam, there is no concern, because the kettle is boiling, as will be explained below.

Pouring from a hot kettle into a pot of cholent standing on the fire

Above, it was explained from the Rema (Yoreh De’ah 105:3) that because of nitzok one may not pour cold kosher food into hot non-kosher food. One should consider the case in which both the upper and lower items are hot: does nitzok apply?

The Chochmat Adam and the Yad Yehudah disagree about this. The Chochmat Adam (klal 59:5) rules that only from cold into hot may one not pour initially, but from hot into hot it is permitted initially. According to him, it would be permitted initially to pour hot water from a kettle into a boiling meat pot, and the kettle would not become meat. But the Yad Yehudah (siman 105, letter 31) holds that even from hot into hot one should be careful initially, and the Pri Megadim (siman 105, Mishbetzot Zahav 6) was unsure about this.

The halachah follows the Chochmat Adam: from hot into hot it is permitted to pour initially, even into something forbidden; all the more so when pouring into something permitted, where one may argue that nitzok does not apply at all, and even according to those who prohibit, this case is permitted.

However, it requires clarification why the steam rising from the pot does not prohibit the kettle by the law of zei’ah, as ruled in the Shulchan Aruch (Yoreh De’ah 92:8). One cannot say that the steam is not at a temperature of yad soledet bo, for the Terumat HaDeshen (part 2, siman 103), cited by the Pri Megadim and Rabbi Akiva Eiger (there), wrote that if the vessel absorbing the steam is boiling hot, it becomes prohibited even if the steam itself is not at the heat of yad soledet bo.

However, the Rosh wrote (Responsa of the Rosh, klal 20, siman 26): “Nevertheless, one must know whether a boiling pot receives zei’ah, for perhaps the heat of its boiling prevents it from receiving the zei’ah.” Therefore, here too, since the kettle is boiling, it does not absorb the steam rising to it from the pot.

Indeed, in the above-mentioned Terumat HaDeshen the opposite appears: if the vessel receiving the steam is boiling, it becomes prohibited even if the steam is not at a temperature of yad soledet bo; this requires further analysis.

Practical halachah It appears that we follow the words of the Rosh, as explained by the Maharsham (Responsa, part 4, siman 85): “But if the upper pot was boiling, one may combine the reasoning of the responsum of the Rosh, cited in the gloss of the Maharlach on the Tur, Yoreh De’ah, see there. Especially since the Bach already wrote in his responsa (new responsa, siman 24) that the entire prohibition of zei’ah is only a stringency, and in any doubt one may be lenient.” See also Responsa Mishkenot Yaakov (Yoreh De’ah, siman 34), Yad Yehudah (long commentary, siman 92, letter 55), and Magen Avraham (siman 451:54).

The Bach’s novel ruling regarding steam that rises gently and does not prohibit

In the new responsa of the Bach (part 2, siman 24), it is explained that one might say that everything stated in the responsa of the Rosh (klal 20, siman 26) and ruled in the Shulchan Aruch (Yoreh De’ah 92:8) — that steam prohibits — applies only when the steam arrives with strong pressure, in a narrow and confined place where it cannot spread to the sides. But in a regular case, where the steam rises gently and has room to spread to the sides, it does not prohibit.

However, the Bach writes there that although this seemed to him to be the halachah, nevertheless from the Terumat HaDeshen (part 2, siman 103), cited by the Rema (Yoreh De’ah 92:8), it appears that even where the steam spreads to the sides, it prohibits. Therefore, he writes that if the steam is certainly hot to the level of yad soledet bo, one should be stringent. But if there is doubt whether it is yad soledet bo, it is permitted.

However, all that we have said — that steam prohibits even when it rises gently — applies only to food located above the steam. But if it is at the side, even though the steam reaches it, it does not become prohibited, as explained in the responsa of the Maharsham (part 4, siman 119, who inferred this from the above words of the Bach). The Maharsham also wrote there (part 4, siman 85): “Especially since the Bach already wrote in his responsa (new responsa, part 2, siman 24) that the entire prohibition of zei’ah is only a stringency, and in any doubt one may be lenient; therefore, if the zei’ah reaches from the side, one may permit it.”

Summary

A person is cooking near a pot that contains something forbidden — for example, a non-Jewish worker cooking her own foods, which are forbidden to eat, in her pan; a person who has a sick person at home who needs to eat something forbidden; or a workplace kitchen where each worker has his own pan and there are non-Jewish workers cooking food without kashrut, while there is oil or spice with high-level kashrut used by everyone. In such a case, there is an initial prohibition to pour oil or any liquid sauce directly from the bottle into the pan. However, there is no problem with one spice jar for everyone, since it is not liquid. After the fact, even if they used oil or liquid sauce, there is no problem.

Regarding meat and dairy, however, one may be lenient; even for a liquid bottle, there is no need to designate separate dairy and meat bottles of oil or sauce.

If there is strong direct steam — commonly when the pot is mostly covered and the flame is high, or in a pressure cooker and the like — and the steam is at the level of yad soledet bo, then even after the fact the bottle becomes prohibited. Likewise, if the pot is dairy, the bottle of oil becomes dairy; if the pot is meat, the bottle becomes meat. In such a case, the spice jar also becomes prohibited or becomes dairy or meat, as appropriate, and there is no difference between powder and liquid.

However, after the fact one may permit it if one of the following conditions applies: 1. the steam is not direct, and one pours the oil or spice from the side; 2. the steam is not boiling hot to the level of yad soledet bo; 3. there is very little steam, such as when cooking with strong heat rising from a dry item in a pan.

It is permitted to pour from a boiling kettle onto a dairy or meat item, and the utensil does not become prohibited.

Rema (Yoreh De’ah, siman 95; siman 105:3); Amarza Lishmecha (issue 100).