1) Preparing the substrate.
The substrate is the food of the mushrooms. Cultivated mushrooms generally include bed or compost mushrooms (Champignons de Paris, pieds-bleu, Coprin Chevelu, etc.) and wood-eating mushrooms which decompose wood and, more generally, lino-cellulosic materials (Oyster mushrooms, shiitake mushrooms, Eryngiis). , ...).
Oyster mushrooms, for example, can be grown on cereal straw, or on wood (logs, shavings, sawdust).
Thesubstrate preparation includes possible grinding, mixing with different materials, humidification, and then generally pasteurization/sterilization. This makes it possible to eliminate some of the microorganisms naturally present in the substrate which would compete with the chosen mushrooms.
pasteurization is generally done with heat by soaking in water at 75° for 1 hour for example, or by steam. It can also be done by soaking for 12 hours in a bath of cold water and slaked lime. The sudden modification of the PH(10-12) will eliminate some of the competitors and create a more favorable environment for the development of oyster mushroom mycelium.
2) Inoculation.
Inoculation, or larding… Slightly barbaric terms which simply mean the sowing of the substrate . The seeds or the mushroom spawn ” generally consists of grains or sawdust colonized by mycelium.
The production of the spawn is the most delicate step in the production of mushrooms because it requires very high conditions of cleanliness and sterility. The white is therefore generally produced in laboratories which sell and offer different varieties.
Each grower has their own sowing technique. The more semen you put, at least there is a risk of contamination. But by using fewer seeds, you can make more substrate and harvest more mushrooms.
The more a substrate is adapted to the mushroom and well pasteurized, the less mycelium it will be necessary to add. On the contrary, a substrate that is little or not pasteurized considerably increases the risk of contamination. That is to say to see the appearance of other micro-organisms (bacteria, mold) and therefore the seeding rate will be higher.
Theseeding rate is the ratio between the weight of wet mycelium used and the wet substrate. So we have a seeding rate ranging from 1-2% in laboratory conditions to a rate of 20% for outdoor cultivation for example.
3) Incubation
This is the stage where the mycelium colonizes the substrate. It passes from grains distributed in the substrate to straw or sawdust. To do this, it will produce a multitude of enzymes specific to each variety and each substrate.
At this stage, its metabolism will release heat and produce CO2. The higher the seeding rate, the faster the colonization will be and the risk of contamination will be reduced. Indoors, the optimal incubation temperature is between 20 and 25°. In nature, it may be cooler, and the incubation period will then be prolonged.
Example: indoors at 22°C, oyster mushroom mycelium colonizes a straw substrate in +-2 weeks and a sawdust substrate in +-3 weeks.
4) Fruiting
Most mycelia produce their fruits (“mushrooms”) following stress which can have different origins: drop in temperature in the fall, physical stress when a branch falls to the ground or the ground is trampled, attacks by bacteria or other organisms, complete colonization of the substrate, competition with other microorganisms, variations in light, variation in oxygen levels, etc.
Oyster mushrooms, for example, fruit automatically as soon as they have finished colonizing their substrate, while morels generally need particular stress to trigger fruiting and the appearance of their coveted fruits.
Fruiting requires a very high humidity rate so that the mushrooms can develop properly.
5) The harvest
After the effort, comfort. The number of harvests on a substrate depends on the variety, the substrate and also the producer who decides whether or not to keep the substrate longer.
The productivity decreases with each harvest and therefore generally producers make 2 to 3 harvests on a substrate, but we have already produced up to 8 harvests on a sawdust substrate. drink.
The quantity also varies depending on the variety, the substrate and the producer, but it is estimated that oyster mushrooms generally yield between 15 and 25% of fresh mushrooms per compared to the moist starting substrate, over 2-3 harvests.