While maintaining my wild yeast ferment, I played with the sponge method, using rye which took well to the yeasts and sugars, I actually listened to the bowl and heard crackling pops of the yeasts fermenting! I split the sponge into two different doughs, one with wheat, whole and white and the other with spelt. I would of baked after making the doughs, and fermenting them, but I had to retard both about ten hours. Once I arrived home I found the wheat full of activity. The spelt a bit more firm, probably from the whole grain spelt that I'd milled. Still the final product, sweet flavors and different crumbs, but both delicious!