Soybean hulls have been found to provide a large amount of nitrogen and carbohydrates to gourmet mushroom substrates. It's one of the ingredients in the well tested and much sought after "Masters Mix".
This includes only a 10lb bag of unsterilized soybean hull pellets. Instructions are not included as it is assumed with advanced cultivation techniques that you know what you're doing. Feel free to ask if you have any questions!