Halacha Yomis - Kashering Quartz OU Kosher Halacha Yomis This column is dedicated in memory of: Rav Chaim Yisroel ben Reb Dov HaLevy Belsky, zt'l Senior OU Kosher Halachic Consultant (1987-2016)

Q. Can I kasher my quartz (stone aggregate) countertops for Pesach? A. Engineered quartz countertops, such as Caesarstone or Silestone, are made from a combination of stone, synthetic resins and pigments. Shulchan Aruch (Orach Chaim 451:8) writes that stone can be kashered. But there are differences of opinion regarding whether one may kasher synthetic materials for Pesach. Rav Belsky, zt”l said that even those that have the minhag not to kasher synthetic materials, as per the psak of Rav Moshe Feinstein zt”l, can still be lenient and kasher these counters. This is because these counters are primarily made of stone and the resin is only a small amount used to bind the stones together. Achronim debate whether we can define a material based on the majority of it components (See Minchas Yitzchak 4:114:4), which in this case is stone. Since not kashering synthetic materials is itself a chumra (stringency), Rav Belsky, zt“l said that one may rely on the poskim that view this material to be like regular stone. However, on a practical level, it is difficult to properly clean and kasher a countertop. Rav Belsky, zt”l would recommend that instead of kashering, countertops should be covered for Pesach.