Kashering Stoves & Ovens
Very high heat for these cooking appliances
Kashering--making something kosher--can be difficult, and--because of the liberal use of boiling water, highly heated appliances, and blowtorches--dangerous. In addition to offering advice, many rabbis would be happy come over and assist you in kashering your kitchen. Reprinted with permission from How to Keep Kosher (HarperCollins).
There are many kinds of cooktops, from standard gas and electric to futuristic radiant heat with a glass-ceramic surface. Gas cooktops generally consist of the pilot burner, a hinged cooktop, metal plates around each burner, and grates, or “spiders,” that rest on those grates. Electric cook-tops are similar, but without the grating, as pots and pans rest directly on the heating coil.
Let the cooktop rest, unused, for 24 hours. Remove all the burner grates and plates and wash thoroughly. Scorn the stovetop. If possible, lift the stovetop and clean underneath. I’ve been amazed at the amount of food that seems to escape into the seamy underside of my gas stovetop. Make sure to clean temperature setting dials as well. Once all the separate parts are cleaned, reassemble your stovetop.
Once the cooktop is cleaned thoroughly and reassembled, turn each burner on high. Check with your rabbi as to the amount of time the burner should remain on. One Orthodox rabbi I spoke with said 15 minutes was sufficient--you want those iron grates or the electric coils to get red hot. According to Conservative tradition, the burners should remain on for 45 minutes. Some Orthodox rabbis say the gas cooktop iron grates may be kashered when you kasher your oven . You can put them in the oven during the self-cleaning process, although you may want to check with the manufacturer that this won’t cause damage.
In order to ensure that the area immediately surrounding the burners is adequately heated and kashered, one Orthodox rabbi I spoke with recommends placing a blech on top of the heating burners. A blech is a metal tin, shaped like an inverted cookie pan [or just a flat sheet of metal], which you place on top of the burners to dissipate the heat if you leave the stove on during Shabbat. When you see the blech glowing faintly red (most visible with the lights turned off), the burners are kashered (and so is the blech). Alternately, cover the burner areas with heavy-duty aluminum foil or a double layer of regular foil.
Keeping Stoves Kosher
As with sinks, two cooktops are ideal in a kosher kitchen, but not necessary The standard cooktop design is to have two columns of two burners, with a space just under a foot wide between the columns. Food does splatter when being cooked, and the space between burners gets quite warm--past the yad soledet bo point [meaning "when the hand shrinks back from it" because of the heat--the point at which Jewish law considers a liquid hot]--so this area is considered treif [unkosher], as probably both dairy and meat foods have splattered on it. If you are cooking and some hot meat falls into that space, you would need to discard the meat. (However, if the space was cold and the meat was cold, you could still use the meat.)