Mushroom composting and cultivation

Mushrooms grow on compost. The compost is prepared by specialized companies. The time from the mixing of the raw materials until the delivery of the compost to the production farms takes four to six weeks. The exact time is dependent on the raw materials and the system used by the compost company.

Once the compost has been applied in production farm, it takes about 16 to 20 days before they can start harvesting mushrooms. Harvest occurs from two to three weeks. After that, it is no longer profitable to harvest further.

The composting schedule

The cultivation schedule

1. Filling of the cell

After 14-18 days the compost is transported to the farm . At the farm the cultivation cell is filled with compost, using a special filling machine. A cultivation cell is a temperature-controlled area with racks. During the filling process, the compost is layered about 20 cm thick, covered with a layer of 5 cm topsoil. This layer is pulled into the racks of the cultivation cell. Topsoil consists of a mixture of peat, that has been mixed by specialized companies. At those farms where phase III remains in house, the compost stays in the cell, but after 14 – 18 days, a layer of topsoil is added to the compost.

2. Mycelium growth in topsoil

After the filling of the cell, the mycelium starts to grow from the compost into the topsoil. This process takes 4-7 days. During the mycelium growth in the topsoil, water is added to the topsoil. By watering during the mycelium growth phase, the mycelium cannot grow to the surface of the topsoil.

3. Regeneration growth

After the mycelium growth in the topsoil, the regeneration growth starts. This phase lasts from 1 – 2 days. During the regeneration growth, no watering occurs and a warm, moist environment is created (comparable to summer weather). Because of this climate the mycelium grows to the surface of the topsoil.

4. Ventilation

After the mycelium has grown to the surface, the grower starts with ventilation which creates autumn-like conditions. Because of the colder air and the lower CO2, the fluffy mycelium starts to contract. Once the mycelium has contracted, after about 5 – 6 days from the ventilation, little buds start to form. These buds (about the size of pinheads) are the mushroom’s primordia. This period is referred to as the budding period. After this period, the Relative Humidity (RH)of the cell is slowly lowered , until the buds start to grow into mushrooms. From bud to harvestable mushroom takes about 5 – 7 days.

5. Harvesting phase

The harvesting of mushrooms occurs in ‘runs ’.

  • The first run is picked during the first 4 – 5 days and yields 16 – 20 kg/m2.
  • The second run starts after about 5-7 days and yields a little less; about 9-11 kg/m2.

The total yield is about 26 to 32 kg/m2.

During the harvest, the mushrooms are sorted and weighted into the correct packaging. This is done to minimize the handling of the product to prevent damage to the mushrooms.

6. Sterilizing by steam
of the cultivation cell

At the end of the cultivation process, the cultivation area and the no longer fertile compost are heated thoroughly. This happens by using steam, to kill all diseases and pests. After the sterilizing, the compost is removed from the cell, then the cell is cleaned thoroughly and a new cultivation cycle can get started.

7. Rapid cooling of mushrooms

After the harvest, the mushrooms are taken to a rapid-cooling area where they will be cooled within 45 minutes from +/-13 degrees C to +/-3 degrees C. This benefits the quality of the mushrooms, they can be wrapped immediately after cooling. If the mushrooms are wrapped at a warmer temperature, it can cause condensation on the inside of the cover or the plastic foil

8. The packaging

During the packaging process, the small boxes are placed on the conveyor of the packaging line. Each box is checked by a checking scale for the correct weight. If it is found to be correct, the box continues to the packaging machine. During this process the boxes are checked visually and then a lid or foil is placed on the box, complete with a label with all the necessary information.

9. Transportation

The packaged mushrooms are ready in a cooling area to be transported to e.g. distribution centres, transhipments, markets or directly to the shops. Geurts Champignons Milheeze delivers nationally and internationally. Our transports also cross the borders!

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