Interview: farming oyster mushrooms on coffee


When you collect all the fresh coffee grounds at Zernike Campus in Groningen, you could easily establish fourteen containers in which a huge oyster mushroom production can take place. Oyster mushrooms were first massively used in World War I in Germany as a subsistence measure. Nowadays, they are grown all over the world for consumption. Also in Giethoorn, a town in the north of the province of Overijssel and known as ‘Venice of the Netherlands’, these mushrooms are grown by a company called Westerzwam. Westerzwam grows their fungi in a special way, namely by using coffee grounds from restaurants nearby. Applying this method, Westerzwam creates a circular economy on a local scale and it provides a short chain solution for circular food production. We visited Westerzwam to discover the how and why of this business.

Doing is the new thinking

Together with Eva Flendrie and Wiebe Lamsma, Gossen Rijkeboer runs Westerzwam. In Rotterdam they came into contact with the first Dutch company that grows oyster mushrooms. All three wanted to bring this concept to the North of the Netherlands. The owners of Westerzwam are trying to show the people this concept of reusing products by opening their market garden in Giethoorn. The reasons of opening in Giethoorn are the nearby restaurants, that use coffee in big amounts per day, and the great quantity of restaurants in the area.

In the backyard of one of the restaurants, Westerzwam has two containers in which the oyster mushrooms are grown. These two containers mimic a different season of a year. Naturally, oyster mushrooms grow in the ground or in the bark of a tree. This type of climate you can find in the first container, where it is humid and dark. When the seeds are ready to produce the oyster mushrooms, the bags are moved to the second container. This container represents summer: there is light and warmth. The mushrooms can be harvested twice per plastic bag. Finally, the mushrooms are brought to the restaurant owners in a cargo bike while they collect new coffee grounds.

This whole process of production is based on the slogan ‘doing is the new thinking’. Westerzwam is not afraid to try, to fall and to try again. The process of making plans and change them over and over again is an important characteristic of this company, according to Gossen. Westerzwam produces its products as natural as possible, therefore flexibility is a must. In different restaurants and at local markets you can find their product. The mushrooms can be used in various dishes: as a main course, on a pancake, as a vegetarian bitterbal, as vegetarian shoarma and so on. Moreover, the remaining of the production can be used to make packaging material. In the end, Westerzwam is still experimenting with the possibilities of using oyster mushrooms.

Figure 1: Interviewee Gossen Rijkenboer (Author, 2018)

Circular economy

The aim of Westerzwam is to tell the story of the circular economy and its benefits. A circular economy is based on the principle of the optimal use and reuse of material in the production chain. For the Netherlands this can create new jobs, less import and less pollution.

To become a part of the circular economy, there has to be a drastic change in the system. A main key point is to think differently about a process or product. Such a new kind of thinking, has been implemented by Westerzwam. The most important characteristic is chain collaboration. Westerzwam needs cooperation with other growers, with the suppliers of the coffee grounds and with the buyers of the mushrooms. Even farmers are part of this chain collaboration. After the oyster production, the remaining of the coffee grounds will be brought to farmers. The farmers use the remaining as fertilizer on the meadows. In the end, there is almost no waste.

However, there is a paradox in circular economies. The paradox is between inventing your own business model and teaching others about your vision. Take for example Westerzwam. They are committed to teach the concept of producing oyster mushrooms to interested people. They offer guided tours, workshops, a grow kit for households and a training at schools. They even deliver complete mobile container nurseries. In addition, a nursery will start soon at AOC Terra in Meppel, a practical school that works according to the concept of ‘learning of the region’. However, the consequence is that you have to be innovative and be able to change to stay progressive, because others know detailed information about your business model

We have to go forward

The given paradox is not a point of concern according to Rossen. On the contrary, he has concerns about the cities in the North of the Netherlands, because more and more young people go to the bigger cities. As a consequence, the small cities become empty. According to him, the circular economy can offer a solution to this problem. By investing their time and energy in the circular economy on local scale, they hope the amount of movers to the bigger cities will decrease and become as much part of the city as they used to be. Production and sales are locally facilitated which will create jobs. If the idea of having bicycle highways between cities in the northern of the Netherlands will be substantiated, a quick deliverance on local scale will become more easy. By taking a step back, the circular economy will be stimulated. Finally, we will go forward.

This article was published in the Northern Netherlands edition, May 2018.

Top photo: by Author, 2018.


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