Mushrooms grow from beer waste in the cellars of Brussels

In Belgium, a country where beer is the culinary king, its brewing also creates magic for mushrooms.

In the cellars of the famed Abattoir meat market in Brussels' Anderlecht neighborhood, Quentin Declerck and his partners have come up with a business idea for the times: Growing exotic mushroom varieties using the spent grains from organic breweries.

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Different varieties of mushrooms grow in various substrates at Le Champignon de Bruxelles urban farm in the cellars of Cureghem in Brussels, Wednesday, Feb. 5, 2020. When the founding members of the company first tried to grow their Shiitake, Maitake and Nameko mushroom varieties using coffee grounds as a substrate, they realized the fungi much preferred organic beer waste. (AP PhotoVirginia Mayo)

In Belgium, a country where beer is the culinary king, its brewing also creates magic for mushrooms.

When they started “Le Champignon de Bruxelles" in 2014, founding members Hadrien Velge and Sevan Holemans first tried to grow their Shiitake, Maitake and Nameko varieties using coffee grounds as a substrate. They soon realized that mushrooms prefer beer.

Quentin Declerck, from Le Champignon de Bruxelles, holds a variety of mushroom growing in a substrate at the company's urban farm in the cellars of Cureghem in Brussels, Wednesday, Feb. 5, 2020. When the founding members of the company first tried to grow their Shiitake, Maitake and Nameko mushroom varieties using coffee grounds as a substrate, they realized the fungi much preferred organic beer waste. (AP PhotoVirginia Mayo)

“There's definitely an advantage to trying to find new things to do with the spent grain because, you know, it's going back into the environment,” said Colleen Rakowski, a brewer at Cantillon.

A Maitake mushroom is highlighted inside a plastic bag as it begins to grow in the cellars of Cureghem in Brussels, Wednesday, Feb. 5, 2020. With a mild ambient temperature never going below 11 degrees Celsius, the cellars host a 3,000 square meters underground urban farm, where Le Champignon de Bruxelles grow exotic mushroom varieties using a local brewery's spent grains. (AP PhotoVirginia Mayo)

Velge says he is not obsessed with the whole organic idea, but the label is a powerful marketing tool for the five tons of mushrooms that they produce every month.

Hadrien Velge, a founding member of Le Champignon de Bruxelles, speaks with a journalist at the company's urban farm in the cellars of Cureghem in Brussels, Wednesday, Feb. 5, 2020. When the founding members of the company first tried to grow their Shiitake, Maitake and Nameko mushroom varieties using coffee grounds as a substrate, they realized the fungi much preferred organic beer waste. (AP PhotoVirginia Mayo)

“I tend to work my oyster mushrooms with thyme microgreens, they work well together," he said.

Quentin Declerck, from Le Champignon de Bruxelles, holds millet which will be mixed with beer waste to make a substrate for growing mushrooms in the cellars of Cureghem in Brussels, Wednesday, Feb. 5, 2020. With a mild ambient temperature never going below 11 degrees Celsius, the cellars host a 3,000 square meters underground urban farm, where the company grows exotic mushroom varieties using brewery's spent grains. (AP PhotoVirginia Mayo)

Different varieties of mushrooms grow in various substrates at Le Champignon de Bruxelles urban farm in the cellars of Cureghem in Brussels, Wednesday, Feb. 5, 2020. When the founding members of the company first tried to grow their Shiitake, Maitake and Nameko mushroom varieties using coffee grounds as a substrate, they realized the fungi much preferred organic beer waste. (AP PhotoVirginia Mayo)

Quentin Declerck, from Le Champignon de Bruxelles, holds a variety of microgreens growing at the company's urban farm in the cellars of Cureghem, Brussels, Wednesday, Feb. 5, 2020. With a mild ambient temperature never going below 11 degrees Celsius, the cellars host a 3,000 square meters underground urban farm, where the company grow exotic fungi varieties and microgreens. (AP PhotoVirginia Mayo)

Quentin Declerck, from Le Champignon de Bruxelles, holds a petri dish with a mushroom culture in the cellars of Cureghem in Brussels, Wednesday, Feb. 5, 2020. With a mild ambient temperature never going below 11 degrees Celsius, the cellars host a 3,000 square meters underground urban farm, where Le Champignon de Bruxelles grow exotic mushroom varieties using a local brewery's spent grains. (AP PhotoVirginia Mayo)

A Cantillon Lambic Gueuze is poured into a glass in Antwerp, Belgium, Saturday, Feb. 15, 2020. The Cantillon Brewery, where Lambic, Gueuze and Kriek have been made since 1900, produces organic beer six months a year. The Le Champignon de Bruxelles makes use of the waste from brewing the beer to make a substrate to grow mushrooms. (AP PhotoVirginia Mayo)

Chef Benjamin Gaugue, creates a dish combining different varieties of mushrooms and microgreens from Le Champignon de Bruxelles at his restaurant, De Bruxelles et D'ailleurs, in Brussels, Friday, Feb. 14, 2020. Gaugue is not only seduced by the savory greens, he also sees the ecological side of a project which implements a form of circular economy in an urban context. (AP PhotoVirginia Mayo)

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In Belgium, a country where beer is the culinary king, its brewing also creates magic for mushrooms.

When they started “Le Champignon de Bruxelles" in 2014, founding members Hadrien Velge and Sevan Holemans first tried to grow their Shiitake, Maitake and Nameko varieties using coffee grounds as a substrate. They soon realized that mushrooms prefer beer.

“There's definitely an advantage to trying to find new things to do with the spent grain because, you know, it's going back into the environment,” said Colleen Rakowski, a brewer at Cantillon.

Velge says he is not obsessed with the whole organic idea, but the label is a powerful marketing tool for the five tons of mushrooms that they produce every month.

“I tend to work my oyster mushrooms with thyme microgreens, they work well together," he said.

Quentin Declerck, from Le Champignon de Bruxelles, holds millet which will be mixed with beer waste to make a substrate for growing mushrooms in the cellars of Cureghem in Brussels, Wednesday, Feb. 5, 2020. With a mild ambient temperature never going below 11 degrees Celsius, the cellars host a 3,000 square meters underground urban farm, where the company grows exotic mushroom varieties using brewery's spent grains. (AP PhotoVirginia Mayo)

Different varieties of mushrooms grow in various substrates at Le Champignon de Bruxelles urban farm in the cellars of Cureghem in Brussels, Wednesday, Feb. 5, 2020. When the founding members of the company first tried to grow their Shiitake, Maitake and Nameko mushroom varieties using coffee grounds as a substrate, they realized the fungi much preferred organic beer waste. (AP PhotoVirginia Mayo)

Quentin Declerck, from Le Champignon de Bruxelles, holds a variety of microgreens growing at the company's urban farm in the cellars of Cureghem, Brussels, Wednesday, Feb. 5, 2020. With a mild ambient temperature never going below 11 degrees Celsius, the cellars host a 3,000 square meters underground urban farm, where the company grow exotic fungi varieties and microgreens. (AP PhotoVirginia Mayo)

Quentin Declerck, from Le Champignon de Bruxelles, holds a petri dish with a mushroom culture in the cellars of Cureghem in Brussels, Wednesday, Feb. 5, 2020. With a mild ambient temperature never going below 11 degrees Celsius, the cellars host a 3,000 square meters underground urban farm, where Le Champignon de Bruxelles grow exotic mushroom varieties using a local brewery's spent grains. (AP PhotoVirginia Mayo)

A Cantillon Lambic Gueuze is poured into a glass in Antwerp, Belgium, Saturday, Feb. 15, 2020. The Cantillon Brewery, where Lambic, Gueuze and Kriek have been made since 1900, produces organic beer six months a year. The Le Champignon de Bruxelles makes use of the waste from brewing the beer to make a substrate to grow mushrooms. (AP PhotoVirginia Mayo)

Chef Benjamin Gaugue, creates a dish combining different varieties of mushrooms and microgreens from Le Champignon de Bruxelles at his restaurant, De Bruxelles et D'ailleurs, in Brussels, Friday, Feb. 14, 2020. Gaugue is not only seduced by the savory greens, he also sees the ecological side of a project which implements a form of circular economy in an urban context. (AP PhotoVirginia Mayo)

With their ambient temperature never going below 11 degrees Celsius (52 Fahrenheit), the cellars are ideal to host a 3,000-square-meter (32,000-square-foot) underground urban farm, where Declerck and his associates produce organic mushrooms.

When they started “Le Champignon de Bruxelles" in 2014, founding members Hadrien Velge and Sevan Holemans first tried to grow their Shiitake, Maitake and Nameko varieties using coffee grounds as a substrate. They soon realized that mushrooms prefer beer.

“It did not work out well with coffee. So we teamed up with the Cantillon brewery down the road," Declerck said. “In cities, the beer waste would normally be thrown away."

The Brasserie Cantillon, where traditional Belgian beers Lambic, Gueuze and Kriek have been brewed since 1900, produces organic beer six months of the year.

“There's definitely an advantage to trying to find new things to do with the spent grain because, you know, it's going back into the environment,” said Colleen Rakowski, a brewer at Cantillon.

“It's important to definitely re-use it as much as we can because it is organic material.”

When beer waste is not available locally, the cooperative relies on the waste produced by other organic breweries outside of Brussels.

Velge says he is not obsessed with the whole organic idea, but the label is a powerful marketing tool for the five tons of mushrooms that they produce every month.

“What really interests me is to produce locally in the city, and to exploit resources that are not used," he said.

Benjamin Gaugué, a cook who honed his skills at the prestigious Georges Blanc restaurant in France and went on to work with rising star David Toutain, is a fan. At “De Bruxelles et D'ailleurs," he cooks with the mushrooms.

“I tend to work my oyster mushrooms with thyme microgreens, they work well together," he said.

Gaugué also appreciates the ecological side of the project, which implements a form of circular economy in a urban context. Once the mushroom harvest is done, the substrates can be used yet again, as fodder or organic fertilizer that Le Champignon gives for free to local farmers.

“They sell good products and promote sustainability," Gaugué said.