– Grains (wheat, rye, millet etc)which are to be used for spawn production should be cleaned and sorted for broken and misshaped grains.

– The grains should not be very old, broken, insecticide or fungicide treated or insect damaged.

– The grain is boiled with an equal volume of water till the water dries out.

– The grain should become soft but it should not get split or allow the starch to ooze out. If there is excess water, should be drained off.

–  The grain should be spread on the plastic sheet and left for some time then mixed thoroughly with CaCo3 @ 8% by the grain weight and Gypsum 2% to prevent clumping.

–  CaC03 helps to maintain the pH of the spawn and also helps in absorbing excess moisture.

– The mixture is then filled in bottle or plastic bags ,plugged tightly and sterilized for two consecutive days at 15 p.s.i for half an hour.

– After 2 days of sterilization the bottles are inoculated with the pure culture of mushroom and incubated at 25 ± 1 °C for 3 weeks.

– By this time, the grains become covered with white mycelium.