How much commercial yeast to add to the final dough when using pre-ferments?
Hi to everybody,
I was wondering...
How much commercial yeast (if any) do I need to add to the final dough when using pre-ferments?
Let´s say I want to bake a recipe that calls for a poolish or a biga.
The questions are:
1. Do I also need to add commercial yeast to the final dough? (notice that I´m talking about adding commercial yeast to the final dough, not the poolish or biga themselves, which they already have a tiny bit of commercial yeast)
2. Will the dough leaven properly just by the action of the poolish or the biga? (maybe it´s not neccesary to add additional commercial yeast to the final dough?)
3. If it´s not necessary to add commercial yeast to the final dough when using a poolish or a biga, What would happen if I actually add more commercial yeast to the final dough?
4. Is there any ratio I should use when trying to calculate the amount of commercial yeast to add to the final dough? (assuming of course, that I´m also adding a poolish or a biga to the final dough)
Let´s take the following example:
My final dough (without using pre-ferments):
flour = 165 g
water = 105 g
commercial yeast = 10 g
My poolish:
flour = 15 g
water = 15 g
commercial yeat = 0,01 g
My final dough (using the poolish):
flour = 150 g + 15 g = 165 g
water = 90 g + 15 g = 105 g
commercial yeast = X + 0,01 g = Y
What should be the value of X?
In other words, how much commercial yeast should I add (if any) to the final dough? (in addition to the 0,01 g of commercial yeast that it´s already contained inside the poolish)
I hope someone can enlighten me about this issue.
Thanks in advanced!