a newbie question: for sourdoughs, we do (at least) a bulk fermentation followed by shaping and proofing. what is the purpose of the proofing period? is it to
1) allow bubbles to get larger (for a more aerated dough going into the oven)
2) increase the yeast population (for more oven spring when the dough finally gets in the oven)
3) some other reason?
i know it is probably some combination of the 2 (or 3). is there a good, detailed writeup detailing directional relationships between bulk fermentation time/temp and proofing time/temp? i am looking less for precise tables and more for the thinking behind these two phases of the dough preparation process.