On Soy Hulls, Oak Supplements, and the Choice to Maximize Yields
Soy hulls and oak supplements boost mushroom yields, but focus on the basics first.
I jumped into talking about soy hull pellets before explaining what they're used for.
Most functional mushrooms grow on hardwoods like oak, alder, poplar, or cottonwood. While mushrooms thrive on oak, the mycelium blossoms with easy access to nitrogen. Nitrogen-rich materials such as soy hull pellets, wheat bran, or beet pulp can provide this boost.
When mixed with oak, these materials create an ideal growing environment for mushrooms, leading to faster growth and increased production. We call these nitrogen-adding materials "oak supplements."
Research suggests that mushrooms grown on supplemented substrate “increased more than 30% the yield in oyster mushroom, P. ostreatus, in comparison to non-supplemented substrates.”
Among the various options, brans and soy hull pellets appear to have the most favorable nutrient compositions for oak-loving mycelium. While other supplements can be effective, they generally don't measure up to these two primary types.
Experiments with beet pulp showed longer colonization times—a week or more—before the mycelium fruited. When it did fruit, it produced about 30% less than soy hulls and bran. For hobbyists, this shouldn't be a significant issue. As long as they're okay with slightly lower yields using the same materials (such as grow bags and oak pellets), beet pulp can still be a viable option.
I want to maximize yield from the same amount of pellets. This reduces plastic and oak waste per pound of mushrooms produced. Therefore, I care a lot about choosing the right supplement.
When starting out with mushroom cultivation, focus on using the correct substrate (pine/hardwood/coir) and the most affordable supplement available in your area. Prioritize mastering the basic growing process before worrying about maximizing yields.
Your wallet will thank you, and you’ll be set up for even more success when switching to new supplements—or you might be completely happy with the yields of the original, cheaper supplement.