I know multiple people that use a single microwave for both Milchigs and Fleishigs. They use covers like in the picture below on top of the food. The explanation I have heard is that since the issue with microwaves is steam, these covers prevent the "treif" steam that gathers on the roof of the microwave from falling down onto the food. Does anyone know of a Halachic source for this?

Thank you

enter image description here

1 Answer 1


One of the best sources seems to be from the Shulchan Aruch. The Shulchan Aruch in Yoreh De'ah 92 writes as follow:

A pan of milk, placed in an oven, underneath a pot of meat - the steam rises, enters into the pot, and renders it forbidden. Rema: If there was actual milk in the pan, then we require sixty times its volume in the meat. All of this is when the pan is open, and the steam rises up from the food itself, to the pan that is above it, and also if the two are so close to each other that the steam that rises is so how that it would make your hand retreat rapidly. If not, then everything is permissible. Therefore, we hang meat (slabs) over dairy pots, and we don't worry about the steam that rises. And if something is covered, then everything is permissible, since it is like two pots that touch each other, which do not make each other forbidden, and all the more so with mere steam. But ideally (lechatchila) one should be strict on all this. (emphasis mine)

The Rosh in Teshuvos HaRosh maintains that steams that comes from something unkosher, remains unkosher. The Aruch HaShulchan on the other hand is more lenient.

Rav Dovid Brofsky cites the Aruch HaShulchan in chapter 108 and quotes:

The Arukh Ha-shulchan (108) writes that the Rema was concerned with thick steam. However, our ovens, which are generally large and ventilated, do not produce such steam and therefore the zei'a should not pose a problem.

Although the Aruch HaShulchan sees no problems with modern-day ovens, Rav Moshe Feinstein clearly does. His view is (Igrot Moshe YD 1:40):

he insists that one should not use the same oven for UNCOVERED dairy and meat foods. If one chooses to cook meat uncovered in the oven, then dairy food must be cooked COVERED in the oven, and vice versa. The cover prevents the food from emitting steam, which prevents the extraction of taste from the oven walls and its subsequent return to the food.

  • 1
    Interesting... In this case the covers have openings on the side. Which seems to be a bit different than absolutely covers. Thank you! Feb 9, 2023 at 18:06
  • @AlexKrupka my pleasure. Please let me know if you need anything else. If you find this to be a a sufficient answer, you can click the check-mark, or if you want to see if there are others with possible answers, you can wait.
    – Shmuel
    Feb 9, 2023 at 20:06
  • It's a machlokes what the Rema means that we should be initially strict with this
    – robev
    Feb 9, 2023 at 21:50
  • Sorry, follow up question. Do we assume that microwaves are the same as ovens? Aren't microwave more likely to steam (that's how their kashered) Feb 9, 2023 at 21:51
  • In fact the article you quote from Rav Dovid Brofsky explicitly excludes microwaves from the discussion Feb 9, 2023 at 22:08

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .