- Electric – Kashering a Glass, Corning, Halogen, or Ceran electric smoothtop range for Pesach use is a bit complex. To kasher the burner area, turn on the elements until they glow. The burner area is now considered kosher for Pesach. However, the remaining area that does not get hot is not kashered. The manufacturers do not suggest covering this area as one would a porcelain top, as it may cause the glass to break. Real kosherization can be accomplished by holding a blow torch over the glass until it is hot enough to singe a piece of newspaper on contact with the glass. However, this too may cause the glass to shatter and is not recommended. As the area between the burners cannot practically be kashered, it would be wise to have a trivet on the open glass area to move pots onto. In addition, it would be wise to place a metal disc, approximately 1/8 of an inch thick, on the burner area to raise the Passover pots above the rest of the glass surface. (Caution: This disc should not extend beyond the designated cooking area.) This will help in case the pot boils over, sending a trickle of hot liquid that would serve as a connector from the Passover pot to the non-Passover stovetop. (Note: Cooking efficiency may be compromised when using metal disc.)
- Gas – For gas stovetops with a glass surface, one may kasher the stovetop grates in the oven with a libbun kal (550° F for one hour). In many such models the grates cover the entire top of the stove and there should be no problem adjusting pots on the stovetop. Food which falls through the grates and touches the glass surface should not be used. For those models where the grates do not cover the entire cooktop surface, it would be wise to place a trivet on the open glass area to move pots onto, as no food or pots may come in direct contact with the non-kashered glass surface.
The glass surface (of the electric smoothtop) must be wiped clean and dry between meat and dairy use.
Non-Kosher to Kosher
Kasher burner areas for gas and electric cooktops as stated above in Passover section. The areas in between the burners cannot be kashered. Therefore, they should be kept clean and dry, and food should not be placed directly on these areas.