Hello everyone. I'm new to the site and very grateful for all of the insight I've gleaned from reading your posts. I'm new to baking and have learned a lot from all of you already.

I'm searching for a recipe for a fruit and nut yeast bread. I've been making a loaf using a straight dough method, but find it to be much too dense when I try to use whole wheat flour. I'd like to use a poolish or biga to see if I can get a more open crumb.

Does anyone have such a recipe? Can I convert the one I already use somehow? It calls for a cup of buttermilk. Wouldn't the buttermilk go bad if I left it out to ferment overnight?

Thanks for any help you can offer -- and for the help you've already given!