One of these loaves came out looking good, with nice color, sheen, and nice blistering. The other looks like it has a smallpox infection. I would love to know what causes those nasty-looking popped white blisters on the second loaf. I don't want to tell you too much about the recipes used because I'd like to avoid biasing anyone's opinion straight away. But if someone could tell me at a glance what is causing the ugly blistering, I'd sure appreciate it. Both breads are sourdoughs and both contain relatively high proportions of levain (about 25% of total flour weight). Both were baked under identical conditions in the same Dutch oven with the lid on for the first half of the bake, then removed to allow browning. Any ideas?