Mi Yodeya is a question and answer site for those who base their lives on Jewish law and tradition and anyone interested in learning more. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

A friend told me that his family will kasher his microwave in general (ie if non-kosher food was heated up in it) but will not kasher it for Pesach, letting it lie dormant instead. Does anyone have a souce for such a distinction? (Let's also assume the tray can be covered, so the issue is only with the microwave itself.)

I know people are generally overly machmir when it comes to chametz. I'm looking for a source for this particular distinction.

share|improve this question
up vote 3 down vote accepted

You wanted to know, why some people might be machmir on this:

From InstituteforDayanim.com

Kashering a microwave for Pesach is impossible since only metal or wood can be kashered for Pesach. Although one can kasher plastic the rest of the year, one should not do so for Pesach. The inside of a microwave is generally not metal and is thus not kasherable.

It goes on to give a method to test if the microwave has absorbed any ta'am (even lifgam), and if it hasn't, it says it may be used. However, this that it can't be kashered, and that the only way to use it is if you're sure it hasn't absorbed anything, may be why some are machmir.

From teach613.org

Although many people will not kasher a microwave for Pesach because it has plastic components and because it is hard to clean properly, if you choose to kasher it the process is as follows. ...

(Plastic can not be kashered for Pesach.)

share|improve this answer
Intersting. I wonder why they limit it to metal and wood? I know the Rama is machmir by glass, but that doesn't necasarily set the general rule. – Double AA Mar 15 '12 at 3:15
@DoubleAA At the bottom of this Star-K article it gives a list of materials that can't be kashered for Pesach. Among them, porcelain, stoneware, and plastic. – HodofHod Mar 15 '12 at 3:22
Hmmm...You've presented particularly perplexing passover pottery precepts! I will have to look into this further. Thanks! – Double AA Mar 15 '12 at 3:26
@DoubleAA The second link I just edited in says that you can kasher stone for Pesach. Either way, this is certainly a good reason for some to be nervous about using microwaves. – HodofHod Mar 15 '12 at 3:30
First link is dead. – Double AA Apr 11 at 3:24

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.