Here the recipe I've been using. I adapted it from a pizza dough recipe I found on epicurious that I liked. The recipe below will make two large loaves. This dough freezes well, so I always bake half and freeze half for later. I bake this on a pizza stone, using a pizza peel to transfer to and from oven.
Sponge (Day One)
1 cup flour
1 cup warm water
1 teaspoon yeast
2 teaspoons sugar or honey
Add yeast and sugar to warm water and allow to dissolve. Add yeast and water to flour, whisk to mix, and let it sit for a day (or two).
The next day, add the following to sponge:
2 cups spent grain
1 cup water
5+ cups flour
It will be a little wet, so you can dust more flour into it as you're kneading. I do the kneading in the kitchen aid mixer with the dough hook. (The wetter the dough, the more the bread will rise in the oven, but it has to be workable and not goopy. Add flour until you've achieved a good consistency.) Return to bowl, coat lightly with olive oil, cover, and allow to rise in refrigerator for 6 hours.
Remove from refrigerator and dump the dough onto a floured work surface. Knead briefly, then cut into two pieces. (This is where I freeze the second half). I like to shake some salt onto the cutting board to knead into the dough. Spread some flour onto a pizza peel, place dough on the peel and shape it into a loaf. Allow to rise at room temp for 1 - 1.5 hours.
Preheat oven to 550F. Just before baking, slash the top of the dough with a knife. Slide dough into oven. At this point, I squirt water into the oven to create humidity, but you can also put a pan of water into the oven. Lower oven temp to 450F and bake for 30 minutes, or until inside of loaf is 200F.
I really hope this recipe works for you! I make it all the time. Having the dough in the freezer is a real time saver.
As an aside, I recently brewed the Bourbon Vanilla Imperial Porter, and that grain has been my favorite so far for baking.
I'll attach a pic of my latest loaf.