No, unfortunately grow bags are single use products.

We at Salai are working together with Sakato Sangyo to create the first biodegradable grow bag for the mushroom industry, but this is a difficult project because we are searching for the right balance. Bags need to be biodegradable, but they can’t start biodegrading during incubation! There are also engineering challenges to make a biodegradable bag capable of handling sterilization temperatures, and so there is not yet a biodegradable bag on the market.

Depending on the scale and availability of local sawdust, it could still be cheaper for major operations to produce their own shiitake logs in the long-term. However, Chinese shiitake logs are cheap for a few reasons.

1. They use a mixture of fermented grasses and stems, rather than a 100% wood substrate.
2. Labor is inexpensive in China and the production scales are huge.
3. There are substantial subsidies to the mushroom industry in China.

Bulk sterilization has some advantages, namely slightly fewer labor expenditures and slightly faster turnover. However, there are also demerits to the process. For one, bulk sterilization does not have the fine-toothed control and precision of the Japanese system. For another, large-scale failures of an entire batch are unheard of in the Japanese system but can happen readily in the bulk sterilization system if any parameters are off. In some regions, putting sterilized substrate and spawn into the unsterilized grow bags leads to extremely high contamination rates as well. The equipment and engineering challenges for bulk sterilization are very high, and quite a large economy of scale, equivalent to four or five big mushroom farms, is needed to run a profitable bulk sterilization system, which is why we don’t recommend it for even large farms.

No. No farm in Japan shakes bags.

Japanese farms are extremely productive using top-spawning. Shaking the bags, aside from the unpleasant labor involved, is unnecessary for mushroom farming. At most it will slightly decrease incubation time. However shaking bags, especially with rough sawdust, often causes pinhole formation and this leads to increased levels of contamination and failed blocks. In addition, Japanese machines are designed to press and form substrate into uniform square blocks or rounded cylinders. Shaking the bags ruins this and causes inconsistent and malformed substrate, which makes them harder to handle and creates less consistency on the shelves. This includes having consistent numbers of blocks on each shelf a consistent distance away from one another. Shaking bags can also have unintended impacts on yield, premature pinning, or lead to excessive small pinnings.

There are many options. Lion’s mane mushrooms grow well on previously used hardwood mushroom compost. The spent mushroom compost from exotic mushrooms using sawdust is a good soil amendment that adds structure, aeration, beneficial probiotics, and nutrients to soil. Research has found spent mushroom compost from exotic mushroom farming also improves the water retention of soil and can possibly increase efficiency of chemical fertilizers. We recommend working out arrangements with local farms and plant nurseries. Another option, as taken by some farms in Japan, is to dry and then pelletize spent blocks and use them as fuel for the autoclave’s broiler.

Yes, in order to get the most use, all equipment from ribbon mixers to bagging machines and inoculation machines, should be thoroughly cleaned after usage. In general, a clean farm is also important for employee morale, health and safety issues, and better for the mushrooms themselves. Periodic deep cleans are also important, but reasonable daily cleaning procedures are key.

This depends on what kind of mushroom you are growing. Some varieties can only grow on hardwood sawdust, others can only grow on softwood sawdust, and some will grow on almost anything. As a general rule, we recommend sourcing what is locally available. The cost of shipping sawdust sourced from one particular tree is rarely worth the small increase in bioefficiency.

No, tests have shown that even when you increase the concentrations of calcium in substrate, the concentration of calcium in the mycelium and fruiting bodies changes very little. Growers add small amounts (1~5 kg per 1000 kg, wet weight, of substrate) calcium compounds as a pH regulator, especially for varieties that have long incubations and during hot, humid months when it can be difficult to regulate the fermentation of stored sawdust or other substrates on a farm.

This also varies between mushrooms, but Japanese research indicates that common commercial varieties such as shiitake, maitake, nameko, enoki, and shimeji benefit from light LED light exposure. The amount, time period, and wavelength of LED light for best results varies by mushroom species, as does the effect, which can range from a mixture of increased yields, shortened incubation times, and higher individual weights.