Cheres - Glassware

QUESTION: Is glass classified as a type of cheres which cannot be kashered?

ANSWER: Shulchan Aruch (OC 451:26) writes that even if glass was used with hot chametz, it does not require kashering because glass does not absorb. This is based on a statement in Avos D’Rabbi Nosson (41:6) that states that glass does not absorb. This is the minhag of many Sefardim. However, Rema writes that the minhag in Ashkenaz was not to permit year-round glass for Pesach even if it was kashered. This is because glass is made from sand, and sand is similar to clay (earthenware). The Magen Avrohom (451:49) explains that the ruling of Rema is only a chumra (extra stringency), and bidi’eved (after the fact) if accidentally year-round glass was kashered and used on Pesach, the food may be eaten. However, one may not continue to use the glass utensils, and they should be put away until after Pesach. Although the minhag of Ashkenazim is not to kasher glass for Pesach with hagalah, the Kitzur Shulchan Aruch (116:13) writes that glass may be kashered with libun kal. Libun kal can be affected by placing the glass items in an oven set at 550F for one hour.

In the next Halacha we will discuss the question of kashering glass for use other than Pesach.

____________________________________________________

The Gerald & Karin Feldhamer OU Kosher Halacha Yomis is dedicated to the memory of Rav Yisroel Belsky, zt"l, who served as halachic consultant for OU Kosher for more than 28 years; many of the responses in Halacha Yomis are based on the rulings of Rabbi Belsky. Subscribe to the Halacha Yomis daily email here.