227. Separating Challah

35:1 Dough from the five species of grain (that is, wheat, rye, barley, oats and spelt) must have a portion called challah separated from it. Before separating challah, we recite the blessing l’hafrish challah, that God commanded us in this matter. One then takes an olive-sized piece of the dough and burns it in fire. The challah is customarily burned in the same oven in which the dough is to be baked.

35:2 In order to require that challah be separated, the dough must contain at least five revi'im of flour, which is the volume of 43.2 eggs. (This is about two and a half pounds of flour, or just over nine cups.)