Blog

rotterzwam is certified B Corp

Going through a certification process can help us make our society more sustainable and professionalize our businesses. We found common ground with our philosophy in ISO and organic certification, ...

Recipe: oyster mushroom burger with tarragon mayonnaise

When we think of a good alternative to a hamburger, we immediately think of the vegetarian version made with oyster mushrooms. They're quick to make and, in our opinion, just as delicious. You sea...

Increased cost of coffee grounds collection? Not at Rotterzwam

The cost of collecting waste [and thus coffee grounds] is rising annually, and by ever-increasing leaps and bounds. This cost increase is also known as inflation, and is largely due to the monetar...

8 Reasons to Distinguish Coffee Grounds From Rot Fungus

Earth Overshoot Day tells us that raw materials are running out, and we're seeing global CO2 emissions rise. It's therefore bizarre that after coffee grounds are collected, the material still re...

rotterzwam supplies mushroom growing units to the Clique

Based on the lessons learned over the past few years at our Rotterdam nursery, we've further developed our mobile mushroom cultivation unit. This has resulted in a climate wall suitable for mushroo...

Recipe: warm salad with oyster mushrooms, green asparagus, chicory and blue cheese

Salads, a summer dish? Not necessarily! In winter, you can easily make a warm salad with seasonal ingredients. This salad is a firm favorite and can be served as a main course with some bread, or a...

Sustainable and circular Christmas package

The Rotterzwam Christmas gift set is a simple yet fun Christmas gift set with a strong focus on Dutch products. It includes many artisanal products such as coffee soap, dried mushrooms, oyster mush...

Residual flows on the soil: the next steps

In recent years, we've collected containers full of waste streams, overcome legal hurdles, measured impact, conducted research, and shared results. The conclusion seems clear: organic waste stream...

Coffee grounds against soil impoverishment

The Dutch drink approximately 40 million cups of coffee a day. This represents only 0.2% of the coffee bean. The rest remains as coffee grounds. Approximately 500,000 kg of coffee grounds and 33 t...

Residual flows on the soil: the impact

Using organic waste streams as soil improvers sounds like a sustainable idea, but what exactly is the impact of this plan? To find out, Ecochain compared several scenarios based on the environmenta...

Recipe: oyster mushroom tempura

Want to surprise your guests with a delicious vegetarian snack? Then this oyster mushroom tempura is a must-try. It's often found in Japanese cuisine in various variations. You don't need a deep fr...

Residual flows on the soil: the research results

This blog series is about our "Back to the Soil" project, in which we investigate whether several organic waste streams can be used as soil improvers in arable farming and how this can be legally m...

Finally, system change regarding waste legislation

Monday, June 21, 2021, was the day. Through BlueCity, the municipality of Rotterdam, in collaboration with DCMR Environmental Protection Agency Rijnmond, opened a Circular Counter where entrepreneu...

rotterzwam is given the status of continued use for collecting coffee grounds

On September 22, 2020, we submitted a request to the DCMR to consider coffee grounds as continued use in the application as a substrate for oyster mushroom cultivation by Rotterzwam. Currently...

The biggest vegan burger

As part of the week without meat, rotterzwam helped create the largest vegan hamburger. Naturally, it was made with oyster mushrooms. A week and a half ago, Zapp Your Planet contacted us and asked ...