Minimum amount of yeast
I would like to ask what is the minimum amount of yeast (commercial) to use in a recipe that would not negatively affect the results.
I have read that yeast can reproduce but in fact it has not enough time to do so during dough fermentation. It just eats (and therefore produces gaz and increase volume, I guess).
Of course lean dough needs less than fat- and/or sugar-rich dough. And less yeast needs more fermentation time. Are there other factors that should be taken into consideration (whole wheat, rye, multigrain...)? And is there a general rule of thumb what would the minimum for different types of bread be? The avarage seems to be 10g fresh yeast (1tsp instant) for 500-600g flour. Can this be reduced?
For example I do not understand why in ABED by Peter Reinhart there are 4g instant yeast for 560-680g flour in one case (eg p. 72/73 - 50% and 100% Whole Grain Rustic Bread) and then 10-15g instant yeast for app the same quantity of flour in other breads (eg p. 83 Every Day 100% WW Sandwich, p. 102 Many-Seed, p. 113 Wild Rice and Onion), when there is not a difference between fat and sugar content. Would it be possible to reduce the yeast amount in all recipes?
Thanks for help