Shulchan Arukh, Orach Chayim 506/שולחן ערוך·אורח חיים תק״ו

1Laws of kneading on Yom Tov. Containing 9 paragraphs:One may not measure flour on Yom Tov in order to knead, but rather should take an estimated amount. Rema: And it is permitted to take flour from the container even though one makes a pit in the flour [Ran, first chapter of Beitzah and chapter Kirah].

2One may not sift flour, even with a variation [from the usual method]. However, if it was sifted yesterday and a pebble or wood chip fell into it and one wishes to sift it a second time, it is permitted even without variation. Rema: And there are those who say that it is permitted to remove the pebble or wood chip by hand (Rashba). But there are those who are strict and forbid it [Maggid chapter 3]. And if nothing fell into it but one wishes to sift it a second time in order that the bread be nice, a slight variation is required, such as [sifting] on top of a table. Rema: And similarly it is permitted to do it through a non-Jew, even the initial sifting, if he varies it slightly [Beit Yosef].

3One who kneaded dough on Yom Tov may separate challah from it and bring it to the kohen [it is permitted even if he separated it the day before]. But dough that was kneaded before Yom Tov—it is forbidden to separate challah from it on Yom Tov. Rema: Rather, he should eat and leave over a bit, and tomorrow separate challah from what was left over. And it is permitted to bake the bread by means of eating from it and separating challah afterwards [Beit Yosef]. And if he wishes, he can knead another dough on Yom Tov and combine them together, and separate from that dough also for what he kneaded before Yom Tov [Hagahot Maimoniot chapter 3, Mordechai chapter Elu Overin, and Beit Yosef in the name of Tosafot, first chapter of Beitzah].

4One who separates challah on Yom Tov and it is impure he should not bake it nor burn it, for we do not burn sacred items on Yom Tov. Rather, he should set it aside until evening and burn it.

5It is permitted to make large loaves on Yom Tov, and we are not concerned that through this one will come to bake more than what is needed.

6"If one had flour or dough in partnership with a non-Jew, it is forbidden to bake it on Yom Tov; rather, he should divide it and bake his own [portion]."

7If a person has much fine bread, he may not bake other bread unless he has household members whom he regularly feeds coarse bread. But if he has much coarse bread, he may bake fine bread.

8It is forbidden to make leaven on Yom Tov except with an alteration, because it was possible to make it while it was still day [before Yom Tov].

9Even if the animal was slaughtered on the eve of Yom Tov, it is permitted to separate the gifts on Yom Tov.