Previously, we learned how to use hagala to kasher a kitchen utensil, even for a large utensil that is too big to immerse. What are the rules and guidelines to follow when doing hagala?
- The same hagala procedure can be followed whether the utensil needs to be koshered due to an accidental mixture of milk and meat, treif (non-kosher) or issur (forbidden foods), or chametz (leavened bread product) prior to Pesach (Passover).
- The custom is not to kosher dairy kitchen vessels for meat use or vice versa, in order to avoid confusion. However, one may kasher a vessel (kli) to render it pareve. For example, one may change a meat knife into a pareve knife and use it to cut food that will be used with dairy.
- Any material that will be able to withstand the heat of the hagala procedure, may be kashered using hagala.
- If the kli cannot withstand these processes — perhaps it is made of plastic and would melt, or perhaps it is glass and would break — it cannot be kashered by hagala and may not be kasherable at all. Consult with your rabbi in such a case.
- No kli made from earthenware (cheres) can be kashered. Earthenware includes what we commonly call "China" or "Stoneware." It certainly includes anything made of pottery or clay.
- Plastic may be kashered by hagala according to some poskim (arbiteurs of Jewish Law) if it can withstand the temperatures involved. Others disagree. If a kli has plastic handles that cannot withstand hagala, the handles must be removed. If they can withstand the heat of hagala, the kli may be kashered in a case where the primary use of the kli is the main part of it and not the handles. This is commonly the case with a metal knife with plastic handles or a metal pot with plastic handles. Many modern pots have plastic handles that can tolerate hagala and need not be removed. Such pots can be kashered with their handles still attached provided that there are no cracks or spaces between the pot and the handle. Food could be stuck inside such a crack and it must be removed before kashering.
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