I don't know if this is the right place, but I just baked my first loaf with a new levain. I made it according to Dan Lepard's instructions in "The Handmade Loaf". It looks exactly like the pictures in his book, and did rise. However, my bread did not. Well, it rose a little bit over four hours (not doubled in height, that's for sure, but I put it in because I needed to go to bed!) and it rose and spread out a bit more in the oven. Certainly those babies are active. But perhaps not active enough?