By: The OU Kosher Halacha Yomis Team
I Forgot To Separate Challah Before Shabbos From The Bread That I Baked. What Should I Do? Am I Permitted To Separate Challah On Shabbos?
Shulchan Aruch (OC 339:4) writes that one is not permitted to separate Terumos and Ma’aseros (various tithes) on Shabbos. Included in this prohibition is separating challah. Mishnah Berurah (261:4) explains that Chazal forbade separating tithes on Shabbos and Yom Tov since this “fixes” the foods and makes them usable. “Fixing” food is forbidden on Shabbos and Yom Tov, since it resembles the melacha of tikun maneh (the activity of fixing utensils). However, outside of Israel, one may eat bread before challah is separated, provided that challah will be separated later. Therefore, if on Shabbos one realizes that they did not separate challah, they should make sure to leave over a slice of bread, so they can separate challah after Shabbos.