Mushroom growing venture is percolating in Raglan

A start-up business in Raglan is taking used coffee grounds and turning them into mushrooms.

Called Champignons (French for mushrooms), the venture is the brainchild of Niels Kolmer and Vanessa Macdonald, who have combined their passion for food and circular economies to grow flamingo mushrooms for high-end restaurants and individuals looking for a healthy diet.

The business partners, both originally from France, are hoping to ebb the flow of ever-increasing coffee grounds ending up in landfills by using this café waste to grow the brightly-coloured fungi native to the tropics and Indonesia.

Niels and Vanessa shared their favourite way to eat the mushrooms and treated the Chronicle to a tasting during the interview – fried in olive oil until caramelised with the addition of garlic, salt and pepper to taste, the flamingo mushrooms were full of flavour with a great texture.

Niels, a materials science engineer, has been testing the mushrooms in different growing conditions under his house in Raglan West and is determined to grow ‘clean’ produce.

“Edible mushrooms are intrinsically healthy and have incredible medicinal properties. But people need to know that when grown on a polluted material they act as sponges soaking up toxic metals in high amounts. And unfortunately it’s almost impossible to know on what soil the mushroom you are eating has been grown. We wish to change that.”

Pasteurised by the hot water during the coffee-making process, Vanessa, a former veterinarian, says the coffee grounds are the ideal material for growing the flamingos and, contrary to popular belief, are not great for putting straight onto the garden.

“Where coffee is grown you won’t see other plants growing because it is the caffeine’s role to suppress the germination of other seeds.”

The pair have been in discussion with Xtreme Zero Waste about the venture and say what they are doing fits nicely with XZW philosophy. The by-product of the sustainable mushroom farm – mycelium-colonised coffee grounds – could feed XZW composting operation in the near future.

From repurposing the coffee grounds as growing material for the mushrooms to opting for reusable plastic growing tubs, Niels and Vanessa say their business model is all about creating a circular economy with a tasty and healthy morsel as an end product.

Keeping it as sustainable and local as possible, they source their mushroom mycelium from Lennart Prinz of Prinz Mushrooms and once the venture is in full swing, they hope to recycle up to half of the coffee grounds in Raglan, with the support from cafés and restaurants.

They know there is the demand for the flamingos, having already talked to restauranteurs in Cambridge and Hamilton and are now looking for a site with access to power and water in Raglan to locate four 20ft containers needed to increase production.

They would love to hear from locals who might have land on which they could set up the business.

For more information about Champignons contact Niels at

Janine Jackson