From the outside the Moreau Street warehouse, located in the heart of the Mercier-Hochelaga-Maisonneuve borough, looks pretty commonplace.

A passerby wouldn't immediately expect to open the door and find an urban farm complete with six greenhouses where oyster mushrooms are growing in stacks of white columns.

mushroom grow

The mushrooms grow in 1,200 containers, located in six greenhouses. (Radio-Canada)

But that's exactly what you'll see when you enter the Blanc de Gris warehouse, where they use old coffee grounds and other restaurant waste to produce urban-grown mushrooms.

Friends Dominique Lynch-Gauthier and Lysiane Roy-Maheu founded the company over a year ago and haven't looked back.

Lynch-Gauthier hadn't always planned on cultivating mushrooms for a living, but said she has no regrets.

"Never in life I would have imagined that... But I'm happy," she said.

The mushrooms grow in 1,200 containers, and Lynch-Gauthier said they harvest about 200 kilograms a week.

Dominique Lynch-Gauthier and Lysiane Roy-Maheu

Friends Dominique Lynch-Gauthier and Lysiane Roy-Maheu founded the company over a year ago. (Radio-Canada)

"I find it beautiful," she said of a freshly picked mushroom.

The conditions in the greenhouse must be just right to harvest the best quality mushroom, so temperature and humidity are carefully controlled.

Embracing the 'circular economy'

Roy-Maheu, who is more focused on the sales and marketing side of the company, said she was attracted by the environmental aspect of the project.

"It's really the concept of the circular economy, so taking leftovers that are destined for the garbage and using it to make food," she explained.

Roy-Maheu said that Blanc de Gris buy old coffee grounds from several restaurants and also collects brewery grains, a by-product from the brewing of beer, from a bar in the area.

When she delivers an order of mushrooms to the restaurant Au Petit Extra in the Ville-Marie borough, she doesn't leave empty-handed.

"They keep the coffee grounds and when I come to deliver the mushrooms, I leave with the coffee grounds. It is a nice exchange."

Au Petit Extra

Some thirty restaurateurs buy mushrooms from the company, including Au Petit Extra in Ville-Marie. (Radio-Canada)

As for the kilogram of mushrooms delivered, that'll end up on customers' plates.

"We tasted the mushrooms, and found them to be exceptional," said chef Julien Laporte.

"It's far removed from the oyster mushroom you can buy in a grocery store. It's a mushroom that's more crunchy, with a nutty taste."

The company currently supplies mushrooms to about thirty restaurateurs in the city, and the co-founders hope to increase their clientele going forward.

With files from Radio-Canada's Olivier Bachand