What is the best kind of brown rice flour to grow mushrooms?

The best kind of brown rice flour for growing mushrooms is typically organic, whole grain brown rice flour. This type retains more nutrients and has a better texture for mycelium growth compared to processed varieties. It should also be finely milled to ensure an even substrate that promotes healthy colonization by the mushroom spores. Avoid any flour with additives or preservatives, as these can inhibit mushroom growth.