very sour bread made from not so sour starter
I have been maintaining a whole wheat starter for a few months mostly making variations on Hamelman's Pain Au Levain. While these breads are very nice, they tend to be almost imperceptibly sour. A few days ago I took my trusty starter and went off in a different direction with it. I did an overnight counter ferment with 550 grams total of equal parts white, wheat, and rye flour, 350g water, and 250g starter. The next day the dough was very soupy and not extendable, but I managed a rough boule shape. While the dough expanded a lot in the oven it didn't get taller, so the final bread was a very wide and flat (less than 2 inches tall) pancake. I was ready to toss it based on looks alone, but when I tasted it I was surprised to find it was extremely and very pleasantly sour. The crumb was pretty nice for over 50% whole grain, and the taste was absolutely addictive. I wondered what had got into my starter, so the next day I used the same starter for a Hamelman whole wheat pain au levain. But while I got back reasonably tasty and pretty loaves, it was back to the mildest of sourness again. I'm not quite sure what I did to get such a sour bread, and I would like to do it again with a nicer shaped bread. Was it the overnight counter ferment? Was it the very high percentage of starter? I'm mystified. Any help would be appreciated. -Varda