Can One Oven Be Used for Meat and Dairy?
Question
Hi, I just moved into a rented flat, and there’s only one oven. I know it’s kosher, but I’m wondering, do I need to use it solely for meat or dairy use, or is there a way to use it for both? Please note that I don’t have the budget right now to buy a second oven.
Answer
Thank you for your question.
Ideally (lechatchilah), one should have a separate oven for meat and dairy, as well as separate racks and trays.
However, if a person only has one oven and wants to use it for both dairy and meat, then in such a circumstance one may do so as follows:
One should wait 24 hours from the last use, thoroughly clean the oven from any residue that may have remained, place the racks or oven dish inside, and then heat the oven at its maximum temperature for one hour.
One may ask, how can this be permitted, when there is a Halacha brought in the Mishnah Berurah, Siman 451, Se’if Katan 19, which states as follows:
משנה ברורה על שולחן ערוך אורח חיים הלכות פסח סימן תנא
וסכינים הבלועים מבשר לחלב די בהגעלה אך העולם נהגו איסור בזה
And knives that have absorbed [flavor] from meat into dairy (or vice versa), it is sufficient to kasher them through hagalah (boiling). However, the common custom is to prohibit this.
We see from the above Mishnah Berurah that the custom is not to kasher cutlery that was used for meat in order to use it for dairy. The reason for this is that since a person is accustomed to using it for meat, they might accidentally continue doing so out of habit even after kashering.
Therefore, one could ask, how can it be permissible to kasher an oven from meat to dairy or vice versa, isn’t this against this halacha?
Hagaon Harav Fried, shlit”a, explains that there are three reasons why, in this case, it would be permitted.
Based on the Magen Avraham:
מגן אברהם על שולחן ערוך אורח חיים הלכות יום טוב סימן תקט
ומכאן משמע שמותר בחול להגעיל כלי חלב לאכול בו בשר או איפכא והעולם נוהגין איסו' בדבר ומ"כ בשם הגאון מהור"ר בנימין מפוזנא ששמע ממהר"מ יפה הטעם למנהג שאם יעשה כן לעולם לא יהי' לו רק כלי א' ויגעילנו כל פעם שישתמש בו וזה אסור דלמא אתי למטעי כדאי' בחולין דף ט' ע"ב והא דשרינן הכא י"ל כיון שלעול' אין משתמשין בו אלא ע"י ליבון ליכא למיגזר כנ"ל:
From here it seems that on a weekday, it is permitted to kasher a dairy utensil in order to use it for meat, or vice versa. However, the common custom is to prohibit this. And I have found, in the name of Harav Binyamin of Pozna, that he heard from the MaHaRaM a reason for the custom, namely, that if one does this, he will end up having only one utensil and will kasher it each time he wants to use it, which is forbidden, lest he come to make a mistake, as explained in Chullin 9b.
And regarding the permissibility in our case (on Yom Tov), it can be explained that since in practice people only use it with libun not just hagala/boiling, there is no need to make a decree, as explained above.
We see that the main concern is specifically with performing hagalah, but if one does libun, it would be permitted. Therefore, the same applies to your oven, since heating it at maximum temperature for an hour is considered like libun, it would be permitted.
Utensils not an oven
Since the custom specifically applies to utensils like cutlery, an oven is not included in this prohibition, as it is a fixed structure.
The Opinion of the Pri Megadim:
The Pri Megadim (Orach Chaim 451:30 and 452:13) writes that if one has no other option, it is permitted to kasher from dairy to meat or vice versa.
To summarize: although, in general, we do not kasher utensils from dairy to meat use, kashering an oven is permitted, especially in your case, where this is your only option, for the reasons mentioned above.
Wishing you much success!
Source
Mishnah Berurah – 451:19
Magen Avraham – Orach Chaim 506
Pri Megadim – Orach Chaim 451:30; 452:13
Talmud Chullin – 9b
HaGaon Harav Amram Fried, shlit”a – Pesakim Ve’Hearot page 87
