Kosher Food In A Non-Kosher Oven
Question: Is it permitted to cook the contents of a covered kosher pot in a non-kosher oven?
Short Answer: One is permitted to cook a covered kosher pot with dry food in a non-kosher oven once in a while, such as when traveling. However, one should not make this a common practice.
I. Covered Pots
The Rama (Yoreh Dei’ah 108:1) rules that a covered pot of dry food may be cooked in a non-kosher oven, even if there is a non-kosher pot currently cooking inside. Because the pots are covered, there will be no steam emanating from the non-kosher pot which could potentially enter the kosher pot. There is also no transfer of non-kosher from one pot to another pot without sauce.
Nevertheless, Rav Moshe Sternbuch shlita (T’shuvos V’Hanhagos 2:380) suggests that one should generally be stringent in such a situation. We are concerned that even though the pot is now covered, you will come to cook an uncovered pot in the oven, which is certainly forbidden. Thus, Rav Sternbuch only permits relying on this leniency “b’akrai” – only once in a while.
Rav Sternbuch adds that even if the pots are doubly wrapped, one should not rely on this leniency.
II. Proof To Be Stringent
Rav Sternbuch supports his strict ruling by noting that the Rama himself limits his leniency to a case where both pots are covered, as opposed to one being covered and one uncovered. If one is covered and one is uncovered, the food may be permitted b’dieved (after you already cooked it), but you should not cook it l’chatchilah. Indeed, Rav Sternbuch notes that the Shach also rules that one should ideally be strict, even if both pots are covered.
III. Practical Ramification
Rav Sternbuch notes that a practical ramification of this question is whether you may eat food heated up in an oven on an airplane or from a hotel. Based on the above, one should ideally not use such a non-kosher oven. This is especially true if the akum puts the food into the oven, as the pot may become uncovered along the way. Even though we don’t “assume” that something asur occurred (“achzukei isur lo machzekinan”), it is prudent to be strict.
Another reason to be strict, suggests Rav Sternbuch, is that there is a chance that there is a “davar charif” – a sharp food – in the uncovered pot, and if so, there is more of a chance that the “smell” (“reicha”) of the non-kosher food will enter the uncovered pot.
IV. The Lenient Case
The only time that Rav Sternbuch permits using this non-kosher oven is when there are no other options and the person is not accustomed to relying on this leniency. Thus, if someone is traveling for only a few days and needs to use a non-kosher oven, he may use the non-kosher oven, provided that his food is completely and tightly wrapped. This is especially true when there is no non-kosher pot in the oven at that time.
Next Week’s Topic: May one use the same gas stove-top grate for both dairy and meat pots?