King Arthur Sourdough recipe
I am contemplating making the King Arthur recipe, Merlin's Magic Sourdough. Here is the link to the recipe. http://www.kingarthurflour.com/recipes/merlins-magic-sourdough-bread-recipe 
My question is this... The recipe calls for 1 cup of starter AND 2 teaspoons instant yeast. The sponge calls for 3 cups of the flour. KA wants you to let the sponge rest for up to 24 hours. That is an awful lot of yeast to rest for that long of a period unrefrigerated. Would I refrigerate the sponge after a couple of hours? Then the recipe says to let the dough rise up to 12 hours for maximum flavor. Again, would that be refrigerated? I can't imagine the pile of dough you would have on the counter after 12 hours with all of that yeast going to town. Plus, if not refrigerated, wouldn't the yeast eat all of the sugar?