They can be. We need organic carbon, so distillers grain would work. Sourcing carbon is the easy part. The key component of what we do is the nutrient from carcasses. They are one of the only untapped sources of organic N that is widely available and low cost (at the moment). Fish and chicken are both great sources – we like chickens in particular because of the N in their feathers and we have literally tons of it available around here year-around.

Just about any type of organic carbon works, but some are obviously better than others. For example, horse manure bedding is already recognized as a great substrate for growing mushrooms and is a great carbon ingredient. We use pine bark here because we use it in our potting media mixes as well.

The only drawback to distillers grain is the initial moisture content. It takes a lot of energy to dehydrate it so we can use it as an ingredient in our process.