You are looking at different thing there. A poolish/biga or sponge are all known as pre-ferments. They are used to develop flavor in the finished product. A sourdough on the other hand is a type of product (characterized by flavor) and it requires management of a sourdough starter which is a whole different animal, as is the flavor. A simple way to make a sponge dough pizza crust is to use 60% of the flour in the sponge portion, mix this with all of the yeast and half of the weight of the flour as water. Mix this together for about 5-minutes at low or medium speed. Be sure to adjust the water temperature to give you a mixed sponge temperature of 75 to 80F (this means that you will probably need to use 70F water). Transfer themixed sponge to a suitably sized container and allow it to ferment for 3 to 5-hours (be consistent with the time), then transfer it back to the mixer and add the remainder of the flour, the salt, sugar (if used), fat and water (ice cold). Mix the dough just until it comes smooth, the temperature should be between 80 and 85F. Then take it directly to the bench for scaling and balling, place into dough boxes, wipe with salad oil, cross stack in the cooler for 2.5-hours, then down stack for the night. On the following day, remove about a 3-hour quantity of dough from the cooler and allow it to te3mper AT room temperature for roughly 90-minutes, then begin using the dough. The dough will remain good to use for up to 3-hours after you begin opening it up into dough skins. Dough that has been left in the cooler will remain good for up to 3-days.
Tom Lehmann/The Dough Doctor
