Why does my leaven sink?
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 baked last week, and failed to test the leaven this way. The resultant loaves were very tasty, but very dense and very sour; probably because I let the bulk fermentation go on so long in an attempt to get some volume increase, which was ultimately minimal.
Any ideas?