Oyster mushroom cultivation
sort by substrate for ease of use as long as we are only dealing with one species
80 pounds of sawdust, 50/50 oak/alder 1 pound of gypsum water added to 65% wet weight
initial moisture content measured by weighing out a small sample of sawdust, drying it in a microwave oven and then weighing it again and calculating % moisture like so:
Wtotal - Wdry = Wwater (100 / Wtotal) * Wwater = % moisture
cooled to room temperature
treated with 3% hydrogen peroxide (3% of wW)
supplemented with Spawn Mate SEII at 7-32% of dry weight (Wdry / 100) * target% = Wsmii
inoculated with 20 pounds of commercial spawn grown on millet (from Amycel, Inc.), then transferred in 12-13 lbs. portions to XL spawn bags (found on eBay?)
First, make sure that the hydrogen peroxide does not react with enzymes (peroxisomes) in the saw dust, as this will spoil the disinfective properties. This can be done by mixing a bit of the sawdust with hydrogen peroxide. If there is no fizzing, simply add gypsum and boiling water. If it fizzes, the sawdust will need to be boiled for about 30 minutes to cease enzymatic activity before the peroxide can be added. Do not be tempted to add the peroxide to the water before boiling, as the decomposition rate of H2O2 increases massively with temperature.
After cooling the wet sawdust to <50oC / 120oF, the peroxide can be added. Once peroxide has been mixed well into the sawdust/gypsum, the substrate needs to further cool to room temperature, then supplemented with 7-32% per dry weight Spawn Mate SEII. The mixing can be done in the spawn bags or in a large plastic tote, but the final mix is put in the spawn bags, which are further sealed.
Original estimates of colonization rates were about 4 weeks, but these turned out to be overly pessimistic. Our blocks were inoculated on two separate occasions, 21 and 27 July 2011, and the first blocks were fully colonized by July 29th and fruiting heavily by 8 Aug (see photo). Once the blocks are completely colonized (see picture), the fruiting can be initiated either by taking them out of the bags, or by making a bunch of X-slits in the bags spaced about 2" / 10 cm apart and placed in a climate-controlled fruiting chamber. The chamber can be constructed by covering a wire shelf rack with thick plastic, adding a small fan and a humidifier (preferably on a timer so it only runs during day time) - temperatures should be within 15-25oC / 60-75oF, and relative air humidity optimally between 90% and 93%.