Calcium Carbonate
When preparing a casing layer it’s important to add to correct buffers to maintain a healthy pH level. For example, unlike hydrated lime, Agaricus mushrooms should not contain gypsum, as it drives the pH down in interaction with metabolites of the mycelium. This will lower the ultimate yield of mushrooms. Calcium Carbonate is the preferred source of calcium in the casing, as it buffers the pH upward.