Look at how much it grew overnight! And yes, that's a nice crusty crust on the top. If you look back at yesterday's picture, I think you'll notice how much it's risen, and how much more dry it looks today. And it certainly had developed an interesting smell. I'll leave it alone through tonight, which will make for a total of about 60 hours, and then I'll peel off the crust in the morning, feed it, and let it ferment for another couple of days. This is getting so exciting!