new to sourdough - great starter, great sponge, bread won't rise
I've been making yeast bread successfully for many years, but I just started experimenting with sourdough. I made a starter from KA bread flour and water and it's really active. Rises like mad. I've tried several sourdough bread recipies, but I can't get the dough to rise. The sponge rises great, and I'm kneading enough (I think - windowpane test is good). The dough, once kneaded, feels great. Then it just doesn't rise. Even more than 12 hours later. It's summer here and the kitchen is warm but not hot. Help?