Alternative Spawn Media

Some mushroom species do not grow well on grain and are better suited to alternative spawn media. Other mushrooms are grown on substrates incompatible with grain spawn. For example sawdust and bran are the preferred spawn materials for the cultivations of wood inhabitors such as Lentinus edodes and Flammulina velutipes. Another spawn media has a perlite bran base. Perlite is vitreous rock, heated to 1000°F. and exploded like popcorn. The thin flakes of bran are readily sterilized while the perlife gives the medium its structure. The recipes are  

Soak the sawdust in water for a least twenty four hours, allow to drain and then thoroughly mix in the bran. If the mixture has the proper moisture content, a firm squeeze results in a few drops between the fingers. Fill the material firmly to the neck of the spawn container (wide mouth). Japanese spawn makers bore a Vi inch diameter hole down the center of the media into which they later insert their inoculum. Sterilize for 60-90 minutes at 1 5 psi. Once cooled, inoculate from agar media, liguid emulsion, or grain. A fully grown bottle of sawdust bran spawn can also be used for further inoculations. 

120 milliliters water 40 grams perlite 50 grams wheat bran 6 grams gypsum (calcium sulfate) 

5 grams calcium carbonate Screen the perlite To remove the fine powder and particulates. Fill the container (small mouth) with the dry ingredients and mix well. Add the water and continue mixing until the ingredients are thoroughly moistened. Sterilize for one hour at 15 psi. Inoculate from agar media or liquid emulsion. 

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Four other methods of preservation include the immersion of slants into liquid nitrogen (an expensive procedure) the inoculation of washed sterilized horse manure/straw compost that is then kept at 36-38 ° F. (See Chapter V on compost preparation) the inoculation of sawdust/bran media for wood decomposers (see section in Chapter III on alternative spawn media) or saving spores aceptically under refrigerated conditions—perhaps the simplest method for home cultivators. 

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