This morning I got up at 4:30, and decided to go ahead and bake the dough I'd prepared: following the directions for the pain Poil�ne recipe (at the end of this post), I'd let the yeasted sponge rise 24 hours, even though I had my doubts when I found it had started to ferment and had an alcoholic taste. As instructed, I had added the second dose of flour and water to the sponge, let it rise another 24 hours. So this morning it was ready. I added the last dose of flour, kneaded it, let it rise, shaped it into baguettes, let it rise. I slashed them with a razor (not very well; I just can't find anything sharp enough), and baked it. Pretty good. There was a slight alcoholic odor if you sniffed the dough, but it was still pretty good. I might've baked it a tad longer for a properly crispy crust, but some of my eaters don't like too much crispiness.

Update
I guess this is the "Poolish method"

This method was first introduced in France by the bakers of Marie Antoinette of Austria, wife of the king of France, Louis the xvi (both were guillotined during the Revolution of 1794). It mainly consists of fermenting for a period of twelve hours a given amount of flour and a minute quantity of fresh yeast (1gr/kg of flour and even less during the summer) and enough water to make this dough quite liquid and elastic (approx. 1lt/kg of flour). At the moment of kneading, we then add the rest of the flour and a bit of fresh yeast. This long process of fermentation with little yeast added permits the development of great amounts of organic acids which imparts the bread an excellent taste as well as long lasting freshness. This technique can be applied to many cereals but convenes particularly well to white (unbleached) wheat flour, and in the making of the traditional baguette. Needless to say, the baguette has become symbolic to Paris but is in fact of Viennese origin, as well as, croissants, since both have been introduced in France by Austrian bakers.

(courtesy Owl's Bread Bakery). Mon dieu! Baguettes are not French!? This will take me a while to digest. Anyway, next week, guess I'll try using a little less yeast. Also, I think I'll refrigerate the dough at some point:

Bacteria are important flavor builders as well. There are bacteria in the dough from the beginning, but as long as the yeast is very active, it consumes sugars as quickly as they're produced, leaving no food for the bacteria, which also like sugar. But when bakers chill a dough and slow down its rise, the cold dramatically reduces yeast activity. The bacteria, on the other hand, function well even in cold temperatures, so they now have an opportunity to thrive, producing many more marvelously flavorful acids.

(from Shirley O. Corriher at Fine Cooking) Mmm. Bacteria! Also, several other links I want to save. This one is a bread with pre-ferment and a minimum amount of yeast; it uses a little rye flour "because it has bacteria that readily develop for enriched flavor". This is a discussion of pre-ferments, including biga and poolish. And here's another. And with these minute quantities of yeast, I could either just wing it, or get a scale.