Mushroom Cultivation (With Simple Diagram)

In this article we will discuss about mushroom cultivation

Mushroom Cultivation

Mushrooms are the fruiting body of edible fungi, commonly belonging to Basidiomycotina and rarely to Ascomycotina.
The mushrooms is rich in proteins, fibres, vitamins and minerals.
In the early years of mushroom culture in the Netherlands, compost was scooped into the mushroom trays and then inoculated with spores. A nine week wait followed, until the mycelium spawned sufficiently, flushing started and the grown mushrooms could be harvested by hand.
The mushroom cultivation process hasn’t changed that much, but the way the successive steps are performed differ immensely.
Mushroom cultivation can be divided into five phases: Composting, Spawning, Casing, Pinning and Harvesting

Phase 1: Composting

The growing cycle of mushroom cultivation starts with compost.
Compost preparation starts with horse manure, get it from large horse breeding companies.
Straw, gypsum, chicken manure and water are added to the horse manure.
Commonly 100 kg of dung is mixed with 33 kg of straw.
Gypsum is added @ 25 kg/tonne (1,000 kg) dung.
The straw improves the structure, gypsum ensures the proper acidity and the two manures are the nutrients.
The compost is produced in tunnels in order to prevent the smell.
Air purification with ammonia wash prevents gas emissions from manure.
It is kept at about 50^oC for one week.

Phase 2: Spawning

Fresh compost is pasteurized in a tunnel at 57-60°C to kill bacteria.
The compost is mixed with spawn (mycelium) that produces mushrooms.
Compost is moved to another tunnel for mycelium to spread.
Mycelium fully permeates the compost in two weeks, making it ready for growers.
Spawn production is a sophisticated process managed by dedicated companies:
Grain is sterilized to prevent infection.
Spores are inoculated into the grain.
Grain is incubated for two weeks at 25°C, then transferred to refrigerator at 2°C to harden it.
The spawn gets a shelf life of 6 months without the mycelium losing its vitality

Phase 3: Casing

The matured compost is spread onto long stainless steel boxes, the mushroom beds.
The beds are inside special dark rooms called cells.
The temperature in the cells is kept warm, at about 23 degrees Celsius.
A layer of peat casing material is added on top of the compost to keep the compost moist.
Over a period of six days, 20 to 25 litres of water is sprinkled on each cell because more moisture is needed.
After this, the fungus has two days to grow through the covering layer of casing soil.

Phase 4: Pinning

Mushrooms grow naturally in autumn but can be cultivated year-round by simulating autumn conditions.
Temperature in the cell is gradually lowered from 23°C to 17°C over four days.
The temperature drop signals the mycelium to start sprouting mushrooms, similar to nature’s process.
Once mycelium fully grows, it begins forming small buds called pins, which develop into mushrooms.
Air temperature and humidity affect mushroom growth:
- Low temperature and humidity: More buds, smaller mushrooms.
- High temperature and humidity: Fewer buds, larger mushrooms.

Phase 5: Harvesting

The temperature is kept steady at 18 degrees Celsius. Mushrooms grow best at this temperature.
Mushrooms will grow 3 cm (1 inch) in a week, In week 3 the first flush is harvested.
The selling fresh mushrooms are still harvested by hand.
Hand-picking ensures mushrooms are removed undamaged.
On average, a picker can harvest between 18 and 30 kilos of mushrooms an hour
Nine days after the first flush, the second flush will be harvested.
The second flush often consists of larger, but fewer mushrooms than the first flush.

Discolouration, weight, and flavourloss are the main problems of harvesting stage of mushrooms.
The following methods are used to Preservation of Mushrooms.
- Canning: Mushrooms are washed, blanched in hot water and citric acid (3-5 minutes)
- Drying: Preservation by reducing the moisture Content.
- Freezing: Subjecting to low temperature (-60°C)
- Chemical Preservation : such as SO₂, sorbic acid, sodium benzoate, ascorbic acid, acetic acid, citric acid.
- Pickling: with salt, oil, spices and vinegar
- Steeping preservation: With salt solution