1,027. Kneading Dough on Yom Tov

Shvisas Yom Tov 3:8

One is permitted to knead a large dough on yom tov. If one kneaded dough on the day before yom tov, he may not separate challah* from it on yom tov; if he kneaded it on yom tov, he may separate challah and give it to a kohein. If the dough is ritually unclean, or if the challah is rendered unclean, the challah may not be baked. This is because we are only permitted to bake on yom tov in order to eat and this challah must be burned. The impure challah may not be burned on yom tov because if sanctified portions are rendered unclean, we do not burn them on yom tov. This is because burning sanctified portions that become unclean is a positive commandment as per Leviticus 7:19, “you shall burn it with fire” but not performing acts of labor on yom tov other than in the course of food preparation is both a positive commandment and a negative commandment. Fulfilling a positive commandment does not supersede fulfilling a positive commandment and a negative commandment combined.

Shvisas Yom Tov 3:9

Ritually unclean challah is left until after yom tov and then burned. On Passover, when leaving the challah unburned will cause it to rise, one may not separate challah from the dough. In such a case, one should bake the whole impure dough and separate the challah afterwards.

*Challah is a portion of the dough that is given to a kohein. The bread we eat on Shabbos is colloquially referred to as challah but it’s really “bread from which challah has been taken.”