Last week I took off challah from a shiur dough and it got mixed into the dough again by mistake. I forgot and baked the challah. My husband asked a rav and he said we should put the old baked challah together with new baked challah which has not had challah taken off yet and have in mind to take off challah for both the old and new dough. I read an article that says you have to be matir neder before three men for the old challah that got mixed in. Do I need to do this? I asked another rav who did’nt see how the other rav’s suggestion would help. He holds that the old challahs are b’chezkas “tevel” and should be disposed of or burned. What is the halacha here?
Under such circumstances, the best course of action would be to perform hataras nedarim in front of three ‘dayanim’ (three regular men will do). By doing hataras nedarim, the challos you baked will revert to their initial status of tevel, and you will be able to take challah from them again.
Sources: See Rema, Yoreh De’ah 323:1 (Taz (2) disputes the heiter of hatarah, but Nekudos Hakesef, and a number of authorities mentioned in Pischei Teshuvah (4) defer his objections); concerning the procedure of hataras nedarim, one should ensure that three dayanim come together, and hatarah should be done in front of them. If this is impossible, see Pischei Teshuva, Yoreh De’ah 228:9, who writes that there is room for leniency in being matir the neder even in the absence of the dayanim (by mail, or over the phone).