I have read some people say that some professional pizza makers use yesterday's pizza dough to make the current day's dough (so that whatever special yeast exists in yesterday's dough is carried forward to the current day's batch). How is that done specifically? Do I just take a small lump of yesterday's dough and mix it into the current day's ingredients and be sure not to add any yeast to the mix? Or does it involve something more complicated? Anyone know any rough ratios to use (e.g. how much of yesterday's dough to use compared to volume of ingredients for the current day's dough)?
Or is it that we need to use some kind of "yeast extraction" method for yesterday's dough in order to isolate the yeast for use with the current day's dough?
I am asking this because I have read stories of how some pizzerias use dough whose yeast has been derived from the first batch of dough they created when they opened for business many years ago (and they just kept the yeast alive by doing things like I am asking about above). But, I can't find any specific steps that detail how in fact this is done.
Any advice, links, etc. would be greatly appreciated.