Pasta Madre

What do you mean by "exhausted pasta madre"? You use the pasta madre to make the dough, and you keep some of the fresh dough as the next pasta madre. How is it exhausted?

Jeremy

I know this is a somewhat old thread, but I have been wondering about the three refreshments at 4-hour intervals before making panettone with pasta madre. I know that the refreshment ratios should be 1 part seed, 1 part flour, and 0.5 part water (provided that the desired hydration is 50%). But the way it is usually done produces a lot of discard during these three refreshments. I am wondering if one could start with a very small amount of seed at the first refreshment and that way avoid any discard. Let's say I need 100g pasta madre for a panettone recipe. I could start with 7g seed, 7g flour and 3.5g water for the first stage, that is 17.5g lievito. Then four hours later add 17.5g flour and 8.7g water, that is about 43.7g refreshed lievito. Then for the final stage I add 43.7g flour and 21.8g water, which results in about 110g active pasta madre, ready for panettone, of which I take the needed 100g for the recipe, and save the remaining 10g to keep the starter going. This way, there is no discard at all. Yet most recipes include a lot of discard during this process, and I am wondering if there is a reason for that.