1. Prepare a clean workspace
Before opening or handling anything, wash your hands thoroughly and clean the work surface. A still, clean room is best. Wipe the injection port (the grey rubber bit in the lid) on the rye jar with the included alcohol swab. The cleaner you are at this stage, the lower your contamination risk later on. General extension guidance for liquid culture inoculation also recommends minimising exposure, disinfecting the injection port, and keeping everything as clean as possible during inoculation.
2. Inoculate the rye grain jar
Attach the sterile needle to the liquid culture syringe and inject the liquid culture through the self-healing injection port in the lid. Before doing this, make sure the injection port has been wiped with the alcohol swab and take care not to touch the needle, as this can introduce contamination into the jar. Be careful when handling the needle, as it is sharp. Once you have injected the culture, remove the needle carefully and place the protective cap back on straight away. After inoculation, leave the jar sealed and set it aside to colonise.
3. Incubate the grain
Keep the inoculated jar in a clean place out of direct sunlight at roughly room temperature. Over the next couple of weeks, the grain should gradually turn white as healthy mycelium spreads. The Mushroom Lab says to wait for full colonisation before moving on, and general home-growing guidance says the grain should look white and stringy as it develops. If the jar reaches roughly 30–40% colonisation, you can carefully break and redistribute the grain once by shaking to help it finish faster, but this step is optional.
4. Know what healthy growth looks like
Healthy growth is bright white. Small yellowish droplets can sometimes be normal metabolites, but strong sour smells or obvious green, black, or other unusual colours are bad signs and usually mean contamination. If contamination appears, the safest option is to dispose of the jar rather than try to save it.
5. Transfer the colonised grain to the Master’s Mix bag
Only do this once the rye grain jar is fully colonised. Prepare a clean workspace first. A homemade still air box is a good idea, as it helps reduce the chance of contamination while everything is open.
Use clean scissors to cut the top of the Master’s Mix bag, keeping the opening as small as possible. Keep the bag open for as little time as you can. Open the grain jar and use a clean knife or fork, wiped first with antibacterial cleaner or another suitable disinfectant, to break up the colonised grain.
Pour the grain into the bag, then tape the top shut straight away. Once sealed, mix the grain through the substrate by gently breaking and shaking the bag by hand from the outside. Then keep the bag in a warm, clean place while it fully colonises.
6. Let the substrate fully colonise
After mixing, keep the bag in a clean area at steady room temperature and let the mycelium run through the Master’s Mix. Do not cut the bag early. Wait until the block is fully white and colonised before introducing fruiting conditions. The Mushroom Lab’s own workflow says the substrate should be completely colonised before fruiting begins.
7. Start fruiting
Once the bag is fully colonised, cut slits into the bag to allow mushrooms to form from the openings. Fruiting is triggered by more fresh air, high humidity, and some ambient light. At this stage, allow fresh air exchange, humidity, and light misting. Fully colonised blocks fruit well when airflow is increased and ambient light is introduced, but direct sunlight should be avoided because it can dry the block out.
8. Humidity and misting
Keep the fruiting environment humid, but do not soak the block. A light mist to the inside of the fruiting area or around the bag is better than drenching the mushrooms themselves. Oyster-type mushrooms do best with high humidity and increased air circulation during fruiting. For Lion’s Mane, high humidity is important, but water trapped in the spines can distort the fruit, so avoid spraying it heavily directly.
9. Harvest
Pins should begin forming once fruiting conditions are right, and they will expand quickly. For oyster-type mushrooms, harvest just before the caps flatten out too far or start curling upward, as this is usually the best stage for texture and quality. Cut or twist them off cleanly at the base using a clean blade or scissors. With good conditions, a second flush often appears after the first harvest.
10. Species notes
This kit works especially well with oysters and Lion’s Mane, which makes them the best choices for most beginners. Some options are more intermediate and are generally less forgiving. Lion’s Mane is slightly less of a starter species than oysters because fruit quality is more sensitive to watering, while reishi shape is strongly affected by oxygen levels.