Phase I

Phase 1, also known as the fermentation process, is the start of the substrate creation. The goal is to create a selective growth substrate for the mushroom. This means the correct supplements have to be present. It is also important to make sure other, competing organisms do not get the ideal conditions. To get to these supplements, it is important to remove the wax coating that is surrounding the straw.


When all the ingredients are combined and a base is created, the process can start. The base contain a lot of sugars and carbohydrates. A part of this is easily absorbed by a lot of organisms like for example different kinds of mould. The mushroom can live really well from the harder absorbable ones. It is very important to remove these easy absorbable to make the substrate selective. For this the bacteria are needed which are injected into the product with the ingredients. They are going to consume these sugars and carbohydrates. This produces activity. Due to this activity this process takes place at a temperature reach of about 80° Celsius. All produced by the bacteria themselves so no mechanical heating is being used to reach these temperatures. To maintain this absorption the organisms need O². As a result of that, the organism will receive an oxygen flow. Due to the presence of nitrogen and high temperatures ammonia (NH³) is being produced. This ammonia also creates a part of the deterioration of the straw.

In the past this process took place outside. Dikes where created of about 2 meters wide and 2,50 meters high. Inside a cold, a warm and a anaerobe zone was created. Because the bacteria attract O² a natural flow was produced. The so called chimney effect. Because this was very environment contaminating due to the ammonia emission, this entire process was moved indoors. These days this process takes place in completely closed tunnels. These are spaces of about 8 x 8 x 40 meters. The floors are completely fit with air flow systems to provide the bacteria with O². The air that is being produced is being washed with sulphuric acid air washing systems socalled scrubbers. The process water that is produced with this is put back into the phase 1 product. So everything is being recycled.

Due to environment investment these days this process needs high financially investments. This is a negative factor in our competing position. On the other side we have the advantage of running the process in less time, because it is being controlled from start to finish by computers, sensors and vents. This was not possible in the outside air, we are less weather dependent these days. Because of this the quality and continuity has been increased and we are able to create a large quantity of high quality substrate.
At this moment the Netherlands and Belgium are the only countries in the world where the substrate process is being done indoors completely and because of this it is very environmentally friendly. On top of that we liberate society of a waste problem by cleaning up large amounts of horse and broiler manure. Environment and quality walk hand in hand at Walkro!