But I am wondering if I could do all the steps for the dough one weekend. Then freeze it and thaw it the weekend after for final rising and baking? Would that work? Do I need to up the yeast amount?
Somewhere in the Bread Bible (probably in the first section on basics), it says that freezing will kill about 25% of the yeast. So if you’re going to freeze, you may want to increase the yeast accordingly, or else allow for a very slow rise. I would probably allow for a longer rise, as this bread is already very yeasty in flavor, brioche has a relatively high proportion of yeast.
You could also try (I haven’t done this but Roland Mesnier makes his brioche this way) mixing the dough by the straight method (skip the sponge) on Sat night early in the evening, let it rise only to 1.5x, then put it into the fridge to finish rising and begin chilling (make sure it’s covered tightly in the fridge, in case it rises out of the container). Later in the evening give it two business letter turns, then put it into the fridge overnight.
Shape and final proof next morning, but it will take a long time if you don’t do anything to raise the temp of the proofing environment. The theory says that if it takes 2 hours at 80F, it will take double that amount of time at 65F.
Please report back on your results, especially if you try freezing- I’m curious to see what happens