Are my Challah’s still Pareve? The status of Challah’s baked in a meat or dairy Oven
A. Baking at the same time as baking meat or chicken:
Covered: If the meat or chicken is covered, it is allowed to bake the Challah simultaneously if the oven is clean of any meat or chicken residue. If the bread is covered it may be done in all cases. In both of the above cases, the bread remains Pareve [although in the former case, only if the oven was not Ben Yomo, as explained next].
Uncovered: If the meat and bread are both uncovered, it is forbidden to bake the Challah together with the meat unless 1) one will not eat the bread with dairy [as the bread becomes meaty], and 2) is only baking enough to last that Shabbos, or is forming the Challahs in a special shape that reminds him of its meat status, so he does not come to eat it with dairy. If one transgressed and baked them together without fulfilling the above conditions, then by today’s ovens, seemingly the bread is forbidden just as if it were kneaded with meat. One is to thus contact a Rav.]
B. Baking in meat/dairy oven not at same time as meat/dairy:
If one desires to bake Pareve Challahs in a meat/dairy oven, the following conditions are to be fulfilled:
- The oven is clean of residue through preheating the oven. [It is forbidden to bake Challahs in it otherwise, unless they have a special shape or are a small amount and will not eat with opposite food.]
- The oven is not Ben Yomo from meat/dairy. Or, the oven is Ben Yomo, but one relies on the preheating of the oven to Kosher its walls.
2. Background-Full Halachic Analysis on Baking Challah/bread/pastries in a meat or dairy oven:
Meat residue in oven: One may not bake bread on a surface that contains meat residue [unless 1) one will not eat the bread with dairy, and 2) is only baking enough to last that day, or is forming the Challahs in a special shape that reminds him of its meat status, so he does not come to eat it with dairy]. If one transgressed and did so, then the bread receives the same law as bread that was kneaded with milk/meat [in which case we rule that the bread is forbidden to be eaten].
How to clean an oven of residue: A meat [or dairy] oven must be cleaned of residue prior to baking bread inside of it, as explained above. The only way a proper cleaning can be accomplished is through performing Libun [even Kal] inside of the oven. [This can be accomplished by turning the oven on to a hot temperature and having it burn out any leftover residue.] It does not suffice to merely clean the oven with a sponge and water, without also turning it on and burning any leftover residue that is inside.
No meat residue in oven: If there is no residue of meat/dairy in the oven, and one preheats the oven to burn any meat/dairy residue that it may contain, then one may bake the Challahs in the oven even if it was previously used to bake meat/dairy. In such a case the Challahs remain Pareve. Some Poskim rule that this applies even if the oven is Ben Yomo of meat/dairy use at the time of the baking. However, other Poskim rule that one may never bake bread in a meat or milk oven which is Ben Yomo and if one did so, then one may not eat the food together with the opposite food but may eat it before or afterwards. Practically, one is to be stringent like this approach if possible and wait 24 hours from meat use prior to baking bread, however, in a time of need one may suffice with turning on the oven for 15 minutes and “Koshering” its walls from its Ben Yomo use, and then bake Pareve Challahs in the meat oven.
3. Background-Full Halachic Analysis on Baking bread and meat or cheese simultaneously in the same oven:
Introduction: There are three Halachic issues involved in baking bread with meat or milk in the same oven. The first and main issue is the suspicion of spillage and contact. If the meat or milk spills and contacts the bread the bread becomes meaty or dairy and is forbidden to be eaten with the opposite food. This gives this bread the same status of bread that was kneaded with milk or meat, which is forbidden to be eaten with exception to circumstances explained above. Another Halachic issue involved in baking the two together, irrelevant of the concept of spillage, is the concept of smell. Initially we rule that the smell of a food penetrates taste into another food. Thus, if bread received the smell of meat or cheese we rule it may not initially be eaten with the opposite food. Another issue is the issue of Zeiah [vapor]. The vapor of a food is considered like the food itself. Hence, if the vapor of meat or cheese enters the bread this gives this bread the same status of bread that was kneaded with milk or meat, which is forbidden to be eaten with exception to circumstances explained above. The issue is especially relevant when cooking in modern day ovens in which the ceiling of the oven receives all the vapor of the foods.
Uncovered: It is forbidden to bake bread at the same time that that one is baking [uncovered] meat or cheese [unless one of the above-mentioned conditions of shape or amount are fulfilled]. [It is initially forbidden to do so even if the oven is wide and flat and even if the meat/cheese and bread are not on the same surface. This prohibition applies to both modern and medieval ovens.]
If the meat or milk or bread is covered: If the meat or cheese is covered [and the oven is clean of any meat or dairy residue and is not Ben Yomo, and there is no suspicion that the meat or cheese will overflow onto the bread] then it is permitted [even Lechatchilah] to bake bread together with the meat or dairy food, and the bread is considered Pareve and may be eaten with the opposite food. [If, however, only the bread was covered, then although in medieval ovens it would be allowed to bake it simultaneously with uncovered meat/cheese, in modern ovens this would need to be avoided due to the issue of Zeiah. Likewise, even if the meat or cheese is covered, if the oven contains residue of meat or cheese, it is forbidden, due to the smell and vapor of that residue. Residue of an oven can only be cleaned through preheating the oven for some time and burning any residue substance, as explained in the next Halacha.]
B. Bedieved if baked together uncovered:
If one baked uncovered bread and meat or milk simultaneously under the same roofing then it is forbidden to eat the bread together with the opposite food, [due to the vapor of meat or milk that it has received]. [Accordingly, if the bread does not have a specific shape and is enough to last for more than one day, then even the bread itself is forbidden. Thus, being that modern ovens today have an issue of vapor, it is forbidden to bake bread at the same time as uncovered meat or dairy, and if one does so it follows the same laws as bread that was kneaded with meat/milk, in which case the bread is forbidden unless it contains a special shape or small amount.]
Summary and Final Ruling:
One may not bake bread with a meat or dairy food simultaneously in the same oven unless one of the following conditions are fulfilled:
1. The bread will only last for one day and one does not plan to eat it with the opposite food. Thus, if one bakes it with dairy, he does not plan to eat the bread with meat.
2. The bread has a specific shape which reminds one of its dairy or meat status.
3. The meat or cheese is covered, and the oven is clean [and not Ben Yomo]. In such a case, the bread remains Pareve and it is permitted to eat the bread with either meat or dairy.
Bedieved if one did not fulfill the above conditions: If one did not fulfill the above conditions and baked bread simultaneously with cheese/meat then the bread is forbidden to be eaten at all.
 See “A Semicha Aid for the Laws of Basar Bechalav” Chapter 97
 See Shach 108:11 or “A Semicha Aid for Learning the Laws of Taaruvos” chapter 108 Halacha 2I and 3A; Chochmas Adam 62:6; Kreisy 108:12; Kaf Hachaim 108:33; Igros Moshe 1:40; See Darkei Halacha p. 242; Mahrsham 3:208; Minchas Yitzchak 5:20; Kinyan Torah 1:24
Opinions that are lenient: See Peri Chadash 108:10 who argues on the entire ruling of the Shach ibid which prohibits the bread; See the following Poskim who are lenient in certain cases even if the bread was actually kneaded with milk or meat: Kreisy Upleisy 97:1 in name of his grandfather; Daas Eish 12 and Chamudei Daniel brought in Darkei Teshuvah 97:21Hakashrus 10 footnote 33 in name of Rav Moshe Halbershtam; Kreisy Upleisy 97:1 in name of his grandfather.
 Michaber 97:1 and 3
 Minchas Yaakov 60:1; Kaf Hachaim 97:18; This is referring to the bread baking of previous times in which the oven was often fueled with fat of the tail of an animal, and the bread would then be placed directly on the oven wall for baking. The same would apply today if one placed the pan on top of meat gravy and the like
 Michaber 97:2
 Kinyan Torah 1:24
 Taz 97:4; Peri Chadash 97:4; Chavas Daas 97:9; Aruch Hashulchan 97:12; Kaf Hachaim 97:34]
The reason: As the fat does not clean off well and requires the oven to be lit in order to burn the fat. [Poskim ibid]
 See Igros Moshe 1:40; Pischeiy Halacha p. 27; 157; Hakashrus 1:40; Kinyan Torah 1:24; Minchas Yitzchak 5:20 or “A Semicha Aid for Learning the Laws of Taaruvos” chapter 108 Halacha 2I and 3A
 Kinyan Torah ibid writes that one is to simply turn the oven on for some time prior to baking the Pareve food and this will verify that any leftover food in the oven has become destroyed.
 See Igros Moshe 1:40; Pischeiy Halacha p. 27; 157; Hakashrus 1:40
 Igros Moshe 1:40; All Poskim who rule Nat Bar Nat is even initially permitted
 The reason: As Challahs are dry and hence do not release vapor. [Igros Moshe ibid] This also follows those Poskim who rule that dry foods do not release a problematic vapor: Toras Chatas 35:6 [See Minchas Yaakov ibid]; Masas Moshe 4:30; P”M O.C. Hanhagos Horaos Issur Viheter Seder Sheiyni 37, brought in Pischeiy Teshuvah 92:6 that only liquids release vapor; Beis Meir 461; Poskim in Darkei Teshuvah 92:164; Igros Moshe 1:40 unless one sees that it released vapor; See Tzemach Tzedek ibid who brings the P”M but then negates his conclusion as being not substantive; See Admur 451:42 regarding a Chararah who states the pot requires Libun because it touches it most of the time, and does not mention the aspect of Zeiah [brought in Tur and Bach ibid], however seemingly, this is simply because Admur is explaining why it needs Libun, and not simply Hagala due to the vapor; Likewise, see Admur 447:9 who permits
 See Pischeiy Halacha p. 27; 157; Hakashrus 1:40; This follows the ruling of those Poskim who rule that Nat Bar Nat is initially forbidden. [See Rama 95:2; Chapter 4 Halacha 1];
Other opinions-Sephardic custom: According to the Sephardic custom, and the Poskim who rule that Nat Bar Nat is initially permitted, the bread remains Pareve even if the oven is Ben Yomo. [See Michaber 95:1]
 The reason: As according to most Poskim, even dry foods release vapor. [See Tur 451:15 regarding Charara “And it releases vapor”; Bach 451:13; M”A 451:30; Yad Yehuda 92 Aruch 53; Masas Binyamin 42:58; Chacham Tzvi 20; P”M 451 A.A. 30; Rivash 295; Tzemach Tzedek O.C. 43; Shoel Umeishiv Chamisha 4; Beis Shlomo Y.D. 1:162 and 164; Maharsham; Daas Sofer; Levushei Mordechai; Poskim in Darkei Teshuvah 92:164; Rav Elyashiv in Beis Yitzchak; See Peri Haretz Y.D. 2:14]
 It does not initially suffice to Kosher the oven before the 24 hours have passed through turning it on, as most modern oven walls are covered with enamel and require Libun Chamur. [See Admur 494:1 [and 461:1; 451:7 regarding Chametz] that an earthenware oven requires Libun Gamur to be Koshered from meat to milk and our oven interiors are plated with enamel which some Poskim rule have the same status as earthenware [Tuv Taam Vadaas Kama 183] However, if one has a self-cleaning oven, then it suffices for one to perform a self-cleaning cycle to clear it of its Ben Yomo status and bake Pareve bread.
 As some Poskim [See Piskeiy Teshuvos 451:49] rule that even enamel is Kosherable with Libun Kal, unlike earthenware, and here regarding Nat Bar Nat one may be lenient like their opinion.
 Michaber/Rama 97:1
The reason: If the meat/cheese and bread are sitting on the same surface, then it is forbidden to do so due to worry that perhaps the meat or cheese will spill over into the bread and make the bread meaty or dairy. [Rama 97:1] Furthermore, even if they are not on the same surface it is forbidden because the smell of the meat is initially considered to be meaty or cheesy and thus penetrates the bread. [Michaber 97:3; 108:1; Chavas Daas 97 Biurim 5; Aruch Hashulchan 97:11] Furthermore, in today’s ovens it is also forbidden due to the vapor released from the meat or milk. [See Rama 108:1]
 Shach 97:2; Peri Chadash 97:3; Lechem Hapanim 97:3; Beis Lechem yehuda 97:4; Kaf Hachaim 97:26
The reason: As we nevertheless suspect that the cheese or meat fat may drip onto the bread. [Poskim ibid]
 This is initially forbidden due to Reicha. [See Michaber 97:3; 108:1; Chavas Daas 97 Biurim 5; Aruch Hashulchan 97:11]
 Michaber 97:3
 See next Halacha!
 As otherwise it make no difference that the foods are covered as hot liquid penetrates fully into a food. Thus the entire idea of being covered mentioned in 97:3 is only with regards to avoiding the issue of smell “Reicha Milsa Hi” while regarding the issue of spillage it serves no benefit.
 Hakashrus Chapter 10
 Rama 108:1; See “A Semicha Aid for Learning the Laws of Taaruvos” Chapter 108 Halacha 2I and 3A for a full analysis of this subject!
The law by medieval ovens: If the bread was baked in a medieval oven [as opposed to modern ovens which pose an issue of Zeiah/vapor, and prohibits the bread completely unless it fulfills one of the conditions brought above.] then the bread is only permitted if a) The bread and meat/dairy were baked in pans. Or 2) The bread and meat/dairy were baked without pans, directly on the oven surface, although the surface was flat, or the bread was higher on the slant than the meat/cheese, and one did not notice any spillage. [See Rama 97:1; Shach 97:2]
 Shach 108:11; Chochmas Adam 62:6; Kreisy 108:12; Kaf Hachaim 108:33
Other Opinions: The Peri Chadash 108:10 argues on the Shach and rules the bread is permitted Bedieved even if it does not have a shape and is a large amount. The above Poskim negate his opinion; See the following Poskim who are lenient in certain cases even if the bread was actually kneaded with milk or meat: Kreisy Upleisy 97:1 in name of his grandfather; Daas Eish 12 and Chamudei Daniel brought in Darkei Teshuvah 97:21; Hakashrus 10 footnote 33 in name of Rav Moshe Halbershtam; Kreisy Upleisy 97:1 in name of his grandfather.
 See Chapter 4 Halacha 6 for the full details on the vapor issue with modern ovens today; Igros Moshe 1:40; See Darkei Halacha p. 242; Maharsham 3:208; Minchas Yitzchak 5:20; Kinyan Torah 1:24