Rereading the posts it seems to me there is a basic confusion here between a "pre-ferment" vs "sponge" vs "long-term starter"
While all of the above have yeast which provides the "rising" power they are fundamentally different.
It seems to me that cook789 is fundamentally interested in reserving risen dough from from prior bread making and using it as the sole (or primary) leavening agent in subsequent bread making. To the best of my knowledge, this is commonly used by professional French bakers for baguettes. Baguettes are basically made from yeast, wheat flour and salt - no oil/butter/fat and no sweetener - so the basic recipe contains within it the optimal ingredients for providing a leaven (with the exception of salt, which retarts yeast growth).
cook789 is adding a twist since s/he wants to add the reserved dough to a sponge (which is essentially a batter-like substance) rather than the "straight dough" method, where the "pre-ferment" is added (after a resting period) directly to all the other ingredients. Essentially, cook789 appears primarily interested in "recycling" risen but uncooked dough as the leavening agent.
cook789 - if you're still reading this thread, then I would like to make a few points
> as you have already learned, many (if not most) recipes for a (non-sweet) yeast-rising bread call for too much yeast. Most commerical recipe writers assume that bakers have little time to spare and want bread ready to bake within a (relatively short) time period. Many are also addressing an inexperienced audience so calling for "too much" yeast in part compensates for the beginner's inability to know when the bread is properly kneaded.
> if you're interested in "recycling" dough from one baking to another, then chose a recipe that has little or no fat/sweetener or or reserve your "pre-ferment" before adding fat/sweetener/non-wheat flours to the dough that's actually going to be baked.
> when using your reserved "pre-ferment" as levening, be patient. Only repeition and experience will let you judge the timing of the rise. If the dough has an unpleasant smell (it's hard to come up with meaningful adjectives here, but "alcoholic", "sour" or "too yeasty" come to mind) then you've got a failure and no choice but to throw it out. Dough starting with a small amount of yeast can take a long time to rise. If the ambient temperature is in the low 70F (or lower) as long as you monitor the dough, you can end up with a quite respectable loaf (just don't expect an additional "loft" during the actual baking)