Questions about how much vermiculite to order? Check out the substrate calculator here.
(Note: vermiculite is very lightweight, making it more difficult to precisely measure by weight. We sell by volume to ensure you are getting a consistent amount each time. The substrate calculator on our website also uses these same measurements.)
Vermiculite is a core ingredient in bulk substrate for the cultivation of many mushrooms, holding the perfect amount of moisture the mycelium needs as it colonizes and fruits inside your fruiting chamber.
What is vermiculite and where does it come from?
Vermiculite is a member of the phyllosilicate group of minerals, resembling mica in appearance. Comprised mainly of silica oxide, aluminum oxide and magnesium oxide, with trace amounts of many other minerals. It is found in various parts of the world, but currently the major mines are located in South Africa, China, Brazil, Zimbabwe, and the United States. Raw mined vermiculite is heated, causing it expand to many times its original volume, a property known as exfoliation.