→Amount of Dough Necessary
# According to Sephardim, one should take off Challah with a Bracha when making a dough with 3.44 pounds (1560 grams) or more of flour and it is a pious practice to remove Challah without a Bracha when making a dough with 2.65 pounds (1200 grams) or more of flour.<Ref>Yalkut Yosef YD 324:6</ref> However, some say that one should only remove Challah with a Bracha for dough that is 5.29 pounds (2400 grams) and without a Bracha for dough that is 3.67 pounds (1666 grams).<ref>Rav Modechai Eliyahu (comments on Kitzur Shulchan Aruch 35:2</ref>
# It is forbidden to intentionally make less than the shiur challah, the minimum amount of dough which would obligate one to separate Challah.<Ref>Rambam Bikkurim 6:15, Shulchan Aruch Y.D. 324:14, Yalkut Yosef YD 324:7. Shulchan Aruch Y.D. 324:14 writes that it is forbidden to make Challah less than the requisite amount to remove Challah in order to absolve oneself of the Mitzvah. The Gra 324:23 points out that this is based on Yerushalmi Challah 3:1 and Pesachim 48b.</ref> The poskim explain that this only applies if one wants to bake a large amount and is intentionally baking it in two parts separately in order to exempt oneself from the mitzvah of Challah, however, there's nothing wrong with baking a small amount if that's all one wants to bake now.<ref> Shach 324:25 and Taz 324:17 write that someone who only has a small piece of dough is nonetheless allowed to bake it and doesn't have to worry about this prohibition since one's intention isn't absolve oneself from the mitzvah. Aruch Hashulchan 324:41 explains further that the entire prohibition is only for someone who wants to bake a shiur challah and intentionally absolves himself from the mitzvah by baking it in halves. Mishna Halachot 8:228 and 19:112 echoes this sentiment explicitly that there's nothing wrong at all with someone who only wants to bake a small amount less than the shiur Challah.</ref>
# If someone bakes Challah in order to separate them into separate loaves there is a dispute if one is obligated to take off Challah. The minhag is certainly to take off Challah.<ref>The Yerushalmi Challah 1:5 cites Rabbi Yochanan who establishes that a woman who bakes Challah in order to separate it to other people in quantities less than the shiur Challah is not obligated to remove Challah. Rambam Bikkurim 6:19 codifies this. Although Raavad disagrees, Shulchan Aruch Y.D. 326:2 accepts the Rambam. Tosfot Brachot 37b s.v. lechem quotes Rabbenu Yechiel's doubt whether there is an obligation of Challah for a woman who makes one dough that is then cut into small pieces to make noodles. Pitchei Teshuva 326:2 writes that the Bach, Perisha, and Levush hold that a woman making Challah to separate it into loaves is obligated to take off Challah. She's only exempt if she gives it other people. With this they defend the minhag of women to take off Challah even though they separate it into loaves before baking. However, the Bet Efraim YD 69 disagrees based on Tosfot above. Instead he distinguishes between someone who makes loaves that are meant to remain separate in which case they are exempt and loaves which are baked together which would be obligated in Challah. Yalkut Yosef (Otzer Dinim Lisha p. 551) writes that we can rely on the minhag and remove Challah even though the dough is separated into loaves.</ref> Similarly, some say that a person who kneads the shiur Challah and then splits it up in two parts both of which are less than the shiur Challah, and freezes one of the parts for later that there is am obligation to take Challah.<ref>Mayan Omer v. 5 p. 116 5:1 cites Rav Ovadia Yosef that a woman who makes a dough with a shiur Challah and then separates that dough into parts that have less than a shiur Challah to be bake at separate times that she is still obligated in Challah.</ref>
# If one makes less than the amount required in Challah in separate loaves, but then puts them back into the same vessel, the vessel combines these pieces to make a Shi'ur of Challah.<ref> Mishna Challah 2:4, Kitzur Shulchan Aruch 35:3; See Pesachim 46a-b </ref>.