Mushrooming Together

Sawdust to 'Shrooms
Written by Jasen

Shiitake block production starts with the hauling of about 800 lb. of slightly aged (about 6 months) oak sawdust into our building from large covered piles outside. The sawdust is then hand shoveled onto a shaker table to sift out all foreign objects and large pieces of wood. I can honestly say I have lifted, by shovel, 50 tons of sawdust a year for 6 years and counting.

Our state-of-the-art shaker table.

These pieces of wood have been removed from the sawdust. They will later be used as mulch in the garden as a base for Wine Cap Stropharia and in various other places around the farm.

Once the substrate is sifted to the desired size it is loaded into garbage barrels and weighed to 300 lb., which is a full blender load. It is then lifted into a blending paddle autoclave to rehydrate and sterilize the sawdust. After one hour of cooking the sawdust is ready to be cooled, inoculated and bagged into 5 lb. blocks. Each blender load produces around 60 blocks. At two loads a day, that's about 31,000 blocks a year...all by hand. 

Once the blocks are inoculated, weighed and sealed they are rolled, on carts, into the incubating room where they will age for about four months. During the incubation period, the blocks go through a decomposition process. They go from brown sawdust to white as the  mycelium takes over, breaking down the wood. The mycelium ages and the blocks return to a dark brown color. At this stage any fluctuation in their environment stimulates them to fruit. Either a large temperature change or physical movement brings on this force, so climate control is very important.

Pictured here are the stages of sawdust into a fruiting block. Clockwise: starting with the loose sawdust, a one day old block in bag, one week old, 2 months old, 4 months old, and finally a fruiting block.

The blocks are then removed from their bags and placed on racks in the fruiting room, where the temperature is slightly cooler and the humidity is around 90%. In one week's time, the blocks form pins, and within 10 days the crop is usually picked. Once the blocks cease to fruit they go into large compost piles to break down further and, eventually, are reused in the garden.

These Shiitakes have waited over four months to grace us with their presence. They stand proud in front of the sawdust pile where it all began.