Is There A Minhag (Custom) Not To Eat The End Slices Of Bread?
Written by Rabbis Eli Gersten, Yaakov Luban and Moshe Zywica of the Orthodox Union
Rav Yaakov Kamenetsky, zt”l, said that he did not know of any source for this minhag. This was also reportedly the response of Rav Chaim Kanievsky, shlit”a. However, the Minchat Yitzchak (9:8) writes that he personally was careful not to eat the ends of a loaf of bread, because it is said to cause one to forget their Torah learning. Although he too does not give any source for this minhag, he supports the minhag. He quotes a Yerushalmi (Terumot 8:3) which says that when it comes to matters of sakana (danger), one must be concerned for what people say, even if it appears to be without merit. He suggests that forgetting Torah knowledge might be comparable to a sakana.
Some have suggested that the source for this minhag is the Gemara in Horayot (13b) which lists 10 things that can cause one to forget their learning. One of them is eating a loaf of bread that is not fully baked. It could be that in some communities the loaves were crammed into an oven and this led to the ends not being fully baked. However, today the ends of the challah are often the crustiest part of the bread, and therefore this concern no longer applies.