The success of the Zwamburg oyster mushrooms

Making food from waste. It sounds like impossible work, but Rob Hermans of Zwamburg is extremely successful in this mission. As a finalist of the Limburg Entrepreneur of the Year, he explains how to sustainably grow oyster mushrooms for his own products and the best restaurant kitchens.

Coffee grounds

It starts with coffee grounds from local restaurants, caterers and other companies in Limburg. This fresh coffee grounds is a residual product, but of great value to Zwamburg. In a shed in Schimmert, Rob Hermans injects fungal threads into the pressed coffee grounds, after which a plant develops, eventually growing into a ripe oyster mushroom.

CO2 neutral growing

Using the coffee grounds is a sustainable choice, but Zwamburg goes further. The cultivation is done as CO2 neutral as possible by using heat pump technology, solar panels and LED light.

In addition, the cultivation has been designed in such a way that it is possible to make the cultivation more sustainable.

In addition, the spent coffee grounds are not simply thrown away either. When the nutrient medium is worked out, it is taken to Attero, which turns it into compost. The 'waste' thus gets a new purpose, as a boost for the garden.

Steels

Then it doesn't stop there. While the stalks of oyster mushrooms are often seen as cutting waste, Rob Hermans looked for local partners to find a useful purpose for them too. Zwamburg's stalks are now processed into other foods. "In grill sausages or in a mushroom/beef burger, a meat-mushroom burger. They are made into bitterballs and croquettes. And pastas. Pasta Pura puts them in ravioli. Furthermore, there's cannelloni. Instead of a combination of ham and asparagus, now asparagus and oyster mushroom," says Hermans.

Continue or stop

Although Zwamburg's story sounds like one big success story, it didn't come naturally. After three years of not earning anything, Rob Hermans was faced last year with the question of whether to continue or quit. He chose the former, despite the high price. Even with the help of volunteers and interns, he still puts up to sixty hours a week into the business. And he has had to invest, for example in a new nursery. In the summer of 2018, a new, larger and more sustainable nursery was built next to the Schimmert water tower. On peak days he harvests 80 to 100 kilograms of sustainably produced oyster mushroom here.

Swam cart

Zwamburg now focuses mainly on growing oyster mushrooms for its own developed products such as the Zwambal, Zwamkroket, Oyster mushroom ravioli, BBQ sausage and Oyster mushroom Spelt-Pasta. These products have been created through collaborations with local partners. Some of these products are sold from the Zwamkar, a food truck with which Zwamburg appears at various local festivals.

Sustainable business