Preparation of Grain Spawn

The optimum moisture content for grain in the production of spawn is between 49-54%, The following formulas are based on cereal rye grain, Secale cereale, which usually has a moisture content of 11%. Some variation should be expected depending on the brand, kernel size, geographical origin and the way the grain has been stored. 

Most commercial spawn makers cap their spawn bottles with synthetic filter discs which allow air penetration and gaseous exchange but not the free passage of contaminating spores. Home cultivators, on the other hand, have used inverted mason lids which imperfectly seal and allow some 

To produce grain spawn of 48-52% moisture use the formulas outlined below and autoclave in a pressure cooker for 1 hour at 15-1 8 psi. Note that considerable variation exists between measuring cups, differing as much as 10% in their volumes. Check the measuring cup with a graduated cylinder. Once standardized, fashion a grain scoop and a water scoop from a plastic container to the proportions specified below. 

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