For me, this loaf was the major stumbling block in the book, the one loaf I doubted I would be able to complete when I began the project. Spent grain bread uses the "spent" or leftover grain from brewing. After the wort has been strained off the grains, the wort is used to create beer. The grains are discarded. While making bread is an ideal use for these spent grains, I was at a loss of how to come by this ingredient. Reinhart suggests exchanging bread for spent grains with a brewer, but I'm afraid I don't know any brewers. So, when I originally came to this recipe, I skipped over it. As I neared the end of the book last summer, I knew it was time to get back to this bread.
Ultimately, my solution was to create my own spent grains.I began by sprouting wheat. After a few day, I toasted the wheat and made my own wort. But unlike the traditional beer maker, I discard the wort and kept the grains. These were dried, coarsely ground, and then incorporated into the bread.
Frankly, I didn't have high expectations for the loaf. I was doing this more from a compulsive drive to complete the book. In fact, I found this to be one of the best breads in the book. While it was way too much work the way I did it, I would certainly make the bread again if I had a reliable source of spent grains.