Introducing our 10 x 1kg MasterMix sterilized fruiting substrate, specifically designed for use with spawn. This unique product consists of 50% oak hardwood and 50% soya bean hull, with an additional 20g of gypsum for added nutrition. Simply add your preferred spawn and seal it back up for optimal growth. This substrate is perfect for faster-growing mushrooms such as oyster and lion's mane. Trust us, your mushrooms will thank you for this nutrient-rich substrate.