I am still getting my feet wet with sourdough and have been perusing through many recipes. I have made a few loaves in which I incorporate the starter into the final dough right off the bat and let that ferment for 12-24 hours. I have also found recipes that use a seperate levain rise. What is the purpose of this levain and how does it differ than adding the starter straight to the loaf? What are your opinions on levain vs. non levain as it seems to add another step and another 12 long, ticking hours until I get my delicious bread.