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As the holiday of Shavuos approaches, balabustas are faced with quite a challenge: plan, cook, and serve a delicious milchig meal amidst the regular schedule of fleishig seudas.  Her family members and guests have anticipated this milchig meal since the end of last year’s Shavuos milchig meal, so she has quite a monumental task ahead of her.

Where did the custom of serving a milchig meal originate? Usually, our Yomim Tovim are marked by an endless string of fleishig meals, since eating “basar v’dagim” is the traditional way to celebrate a seudas mitzvah or a seudas Yom Tov.  Amongst many different reasons for making a milchig meal on Shavuos, there are two reasons that stand out.  The first is that the Jews did not have time to kasher their keilim for fleishigs after receiving the mitzvos of kashrus, including shechita and bedika of meats, at Matan Torah.  Another reason for the custom of serving a milchig meal is to show that we are already keeping the mitzvah of basar v’chalav by having a milchig meal and then a fleishig meal.

Many Jewish families do not have the luxury of a large, designer kitchen with two complete sets of appliances, especially a full-size milchig oven.  So how can the balabusta create the much-loved milchig meal for her family and guests without a full-size milchig oven?

It is brought down from the Magen Avrohom, amongst others, not to kasher from milchigs to fleishigs (and vice versa) unless special conditions are met.  This prohibition is out of concern that a person might forget what the current status of the equipment is and accidentally commit the issur of basar v’chalav.   Some notable exceptions are: changing from fleishig to milchig for Shavuos and changing from chometz to Pesach.

An oven must be kashered between fleishigs and milchigs because of zeya – steam condensate – that rises and stays on the top layer of the oven.  The mixing of vapors may render the oven and keilim non-kosher.  In general, there are many levels of kashering an oven.  The most stringent level of kashering is kashering from non-kosher to kosher.  In such a case, the oven must be carefully and thoroughly cleaned, left idle for 24 hours and kashered with a complete self-clean cycle (approximately 950° F).  This method seems to be the standard protocol accepted by most poskim.*  Ovens without self-clean cycles must be torched and sometimes filled with hot coals.  A lesser level of kashering involves kashering between two different kosher statuses.  The most stringent of these levels is kashering from fleishigs to milchigs and vice versa.  The oven must always be thoroughly cleaned, but given that we are going from kosher fleishigs to kosher milchigs, many opinions maintain that a self-cleaning cycle is not necessary.  Leaving the oven idle for 24 hours and burnt out on the highest temperature (approximately 500° F) for one hour is generally accepted as sufficient.  If you prefer not to kasher your oven for Shavuos, it is sufficient to double-wrap the food you are baking with silver foil and place silver foil under the pan to catch any overflow.  The easiest level is kashering from fleishigs or milchigs to pareve.  Many poskim are lenient in this case and do not even require waiting 24 hours before kashering.

*This article is not intended to be a P’sak Halacha. Please consult with your local Orthodox Rav for halachic guidance.