BH
I heard bidieved if your in situation where you don’t have lechatchila a Kosher oven you can wrap the object in aluminum once and then after 2 times after and after you can eat the food as long as the vapors from outside the wrap from the walls of the oven won’t enter inside the wrap. Where does it talk about this in Shulchan Aruch or Halacha?
I found an article by Star-K and one by OU Ⓤ that talk about this issue.
Star-K states "If one wants to cook in a treif oven, the kosher food should be double wrapped. That is why kosher airline meals heated in treif ovens are double wrapped."
And the OU article gives more detail...
"The Rama rules that food cooked in an oven previously used for non-kosher becomes treif whenever there is zeiah [vapor from the food], even though the two foods were not in the oven at the same time. Thus, it is clear that zeiah circulates and thereby acts as a bridge through which ta’am is transferred from the oven surface to the food."
Later...
"Rav Moshe Feinstein [gives] two important qualifications: Zeiah does not circulate in the oven if
a) the food is covered (see Rama 92:8), or
b) the food is a dry substance."
The OU offers the following:
"What would happen if you are staying in a motel and wish to use the oven to prepare your meals? The oven is dirty and you are not inclined to spend your vacation cleaning the oven. Based on our previous discussion, it follows that one may use a non-kosher oven simply by covering the food. The cover eliminates the circulating zeiah, and therefore the non-kosher oven has no impact on the food. However, because the oven is treif, it is best to use a double wrap to insure against any zeiah leakage."
The links are included so you can follow the sources and read in greater detail. The reader should consult a rabbi before putting this in to effect to ensure the reader follows halacha as there are additional considerations.
https://oukosher.org/publications/is-your-oven-kosher-part-i/
