I'm a new baker working on the Tartine basic loaf. I was going to bake yesterday, so followed the instructions "the night before you plan to mix the dough...". The next morning, about ten hours after feeding the starter, the leaven sank when I put it in a bowl of water. The kitchen temperature was about 72F. I let it stand another couple hours; same result. I let it stand another couple hours; same result. I let it stand another couple hours; same result. You get the idea... I re-fed last night, with the same results this morning.
I'm using my breadmaker to make a multi grain bread. It was looking great, having risen almost to the top of the bread pan. Then, it started to sag. At first, the middle collapsed a little, then, the sides almost caught up. The situation is not terrible as the bread will be finished shortly and it still rose enough, however, it was around an inch taller.
What caused the drop? Itmust be too much, or too little of some ingredient.