Articles

By Rabbi Dovid Cohen, Administrative Rabbinic Coordinator

Q. My designer suggested we get an induction stovetop.  From a kashrus perspective, is that any different than the gas stovetop I currently have?

A. Induction stovetops heat pots without the actual cooktop getting hot.  Rather, when the “coil” is on, it remains cool to the touch, and it can only cook when a pot which is electrically conductive and made of ferromagnetic material touches it.  When that happens, the pot becomes hot, and the food cooks.  Even when the food is cooking, the “coil” is not hot, and the only reason the surface becomes at all hot is that some heat radiates from the pot and food!

This unusual method of cooking poses considerable complications for a kosher home.  From the kosher perspective, it means that each cooktop (or each area on the cooktop) must be designated for meat or dairy use.  In a standard gas or electric stovetop, the letter of the law is that the same burner can be used for both meat and dairy since the hot fire/coil incinerates and kashers the area from any meat or dairy that spills onto it.  But the induction stovetop never becomes hot enough for that, and, therefore, it can only be used for either meat or dairy, but not for both.

A related issue is that there is no realistic way to kasher the induction stovetop if it became non-kosher, or if one wants to use it for Pesach.  It is covered with glass, which means that it cannot be kashered with hag’alah (i.e., pouring boiling water on it).  Libun kal (i.e., heating with a flame) is halachically acceptable for the surface – and is what is used for other glass stovetops – but is not physically possible, since the induction coil does not get hot.  Since the surface cannot be kashered, the only way to use it on Pesach is to put ferromagnetic discs (a.k.a. diffusers) onto the surface.  [The discs are widely available for purchase.]  The discs will serve as a barrier between the surface and the Pesach pots and allow the stovetop to be used for Pesach cooking.

The induction stovetop also poses concerns for Shabbos use, because when the pot is lifted off the surface, this causes the coil to become idle.  This means that food left on the cooktop cannot be removed on Shabbos.  Once again, this issue can be overcome by putting the pots onto ferromagnetic discs before Shabbos.  Wherever a disc is located, the coil will remain on regardless of whether a pot is present, and, therefore, the pot can be removed from the disc on Shabbos.

Lastly, an induction stovetop complicates the ability to create bishul Yisroel when one has non-Jewish help in the house.  On a standard stovetop, the Jew can light the fire in the morning, and any cooking done on that fire will be considered bishul Yisroel.  However, as we have seen, if there is no pot on the induction stovetop, turning on the coil has no noticeable effect.  Therefore, unless one places ferromagnetic discs on the stovetop (which will keep the coil “on”), the Jew will have to put the pot onto the fire each time someone wants to cook on that surface.

This article first appeared in the Let’s Talk Kashrus column, Yated Ne’eman, March 15, 2024.