Inoculating Mushroom Grains with Liquid Culture

Inoculating sterilized grain with mushroom liquid culture is a fundamental process in mushroom cultivation that facilitates the growth of mycelium, the vegetative part of fungi, which ultimately leads to mushroom production. The first step involves preparing your sterilized grain, often referred to as grain spawn, which typically consists of grains such as rye, wheat, or millet. These grains should be soaked and then sterilized in a pressure cooker to eliminate any potential contaminants that could hinder mycelial growth. Once the grains have cooled to a suitable temperature, it's essential to ensure a sterile environment for the inoculation process to avoid introducing unwanted microorganisms. At this stage, you can introduce the mushroom liquid culture, which contains viable mycelium suspended in a nutrient-rich broth. Using a sterile syringe, draw up the liquid culture and inject it into the grain spawn bag or jar. The injection point should be done in a way that minimizes exposure to air which could introduce contaminants. We recommend using a laminar flow hood or a sterilized glove. Once you have inoculated the grains, they should be kept in a warm, dark environment for optimal colonization—preferably 75-80 degrees. Over the next few weeks, the mycelium will begin to colonize the grains, turning them white as it grows. Monitoring for any signs of contamination during this period is critical, as it can compromise the entire batch. Once the grains are fully colonized, they can be used as spawn to inoculate larger substrate blocks, leading to successful mushroom cultivation. Proper handling throughout the process enhances the chances of a bountiful “fruiting mushroom block”. Check out the detailed video above!