Preinoculated logs are available from some commercial producers and a few mail order companies. Prices range from $18.00 to $45.00 for a log 4 to 6 inches in diameter and 18 to 24 inches long. The logs are ready to fruit and even come with directions and a soaking container. You will be able to fruit these logs every 10 to 12 weeks for about 2 to 3 years.
For the less patient gardener, sawdust block kits cost $15.00 to $30.00 each and must be ordered from a shiitake spawn vendor (Figure 12). They are made from hardwood sawdust, grains, and other additives necessary for mycelia growth.
| Figure 12. The white sawdust block (right) is about 2 months from fruiting, while the brown block (left) can now be removed from the bag and fruited. | |
The ingredients are placed in a heat resistant bag and are then autoclaved (which is similar to pressure cooking). After the ingredients cool, shiitake spawn is added to the bag mixture and the bag is sealed. Each bag has a small breathing patch for air exchange. As mycelia grow, the sawdust mixture turns white. When the entire mixture is coated white, this is called a "white block." A white block is not ready to fruit.
During the next 2 months, the white block will gradually turn into a "brown block." The brown coating is a hardened shell that helps prevent moisture loss and contamination. When the block is completely brown, you can remove it from the bag and it will usually fruit without soaking. In most cases, you can buy the blocks at either stage.
After the block is removed from the plastic bag, keep it in a humid location, where it is exposed to outdoor or fluorescent light. Fruiting should begin within a few days. After all of the mushrooms are harvested, the block will enter a resting state. Sawdust blocks will need some daily misting or a humid environment. You will be able to fruit them again in 3 to 4 weeks by soaking for 12 to 24 hours. Blocks will rarely fruit more than five times.
Often, blocks become contaminated and can only be fruited a few times. You can harvest up to 1 to 2 pounds of shiitake mushrooms from each block. The first two harvests will produce more mushrooms than later harvests (Figure 13).
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Figure 13. You can harvest several pounds of shiitake mushrooms from a sawdust block. |