Rotterzwam

RotterZwam is a sustainable company based in Rotterdam that specializes in growing edible mushrooms, particularly oyster mushrooms, using coffee grounds as a substrate. Founded by Siemen Cox and Mark Slegers, the company operates out of the old Tropicana swimming pool, where they repurpose coffee waste that would typically be discarded or incinerated. RotterZwam not only produces high-quality mushrooms but also a range of delicious vegan snacks, such as crispy oyster mushroom bitterballen, croquettes, and sausage rolls, all made with at least 30% oyster mushrooms. The company is committed to sustainability and the circular economy, actively collecting coffee grounds from a network of local processors to minimize waste and CO2 emissions. They offer a grow kit that allows customers to cultivate their own mushrooms at home using their coffee grounds, fostering a hands-on approach to sustainability. Additionally, RotterZwam conducts workshops to educate the public about fungi, waste management, and how to create mushroom substrate. They emphasize the importance of reusing shipping packaging, offering a deposit return for packaging handed back. RotterZwam also provides a promotional discount for companies participating in their coffee grounds collection program, aimed at increasing their outreach and impact.