I love making challah for shabbat and it’s very special when I make enough to separate challah with a bracha, but I’ve run into complications. My recipe calls for 3 kilos of flour, which is a bit more than I need. Since I’m usually making challah for somone else and I’m not there every week, I usually make up dough with 3 kilos of flour and bake only as much as they need for shabbat (about 2/3) then i freeze the rest of the dough to be baked the next week. I heard that there is a problem with taking challah if the dough is not all baked the same day. the amount I want to bake usually falls into the take-challah-without-a-bracha range. What should I do? And what if I want to freeze a whole batch (already formed into challahs) and bake it another day?

According to the Shulchan Aruch the obligation of taking Challa begins once the batter has been made. Taking Challa once things have been baked is only if one did not take Challa earlier. (שולחן ערוך יורה דעה סימן שכז סעיף ב,ז )