May 2018 | view this story as a .pdf

Indoor mushroom cultivation is thriving in Maine. We follow three companies through the process.

By Claire Z. Cramer

If you like mushrooms–and who doesn’t?–you’ve probably noticed oysters, maitakes, shiitakes, and other exotic varieties receiving star treatment in Portland’s restaurants. That these are Maine mushrooms, both cultivated and foraged, adds to their local and often organic pedigree. You may find them sautéed, roasted, or starring on designer pizzas. At the charming new Elda in Biddeford, diners are presented at the start of the meal with warm, fragrant cups of clear mushroom broth infused with a sprig of thyme and a twist of lemon.

At Tipo, the casual Italian café on Ocean Street, an assortment of North Spore mushrooms comes in a sauce that works as an appetizer or a light lunch. Chef Michael Smith “makes the sauce from mushroom stock, marsala, and just a dash of sherry vinegar,” says the waiter as he sets down the shallow pottery bowl. A tangle of tender mushrooms in its rich, dark sauce is heaped on a crisp, creamy-centered square of fried polenta and garnished with dabs of white-truffled egg yolk. It’s the earthy, exotic essence of mushroom mystery.

This inspires a trip to the North Spore stand at Portland’s Saturday farmers’ market. Vivian Ewing walks me through the varieties she’s offering today. “Shiitakes and oysters are the most popular. These chestnuts are prized for their color.” They’re slim-stemmed, with rich russet caps. “And we call these lion’s manes, but they go by other names, too, like hedgehog and bear’s tooth.” Aptly, they’re big, white, and ruffly.

“I cook them all pretty much the same.” She smiles. “Just saute them in butter with garlic.”

North Spore’s wares include products made from medicinal mushrooms. There are tins of dried chaga, which resembles smashed fragments of dusty bricks, for simmering into tea. There are eye-dropper bottles of mushroom tinctures, which can be taken as a few drops on the tongue or in herb tea. Most fascinating is a plastic bag about the size of a shoebox, which appears to be stuffed with soil. Out of a hole in the bag, a fist-sized cluster of shiitakes is growing.

“That’s an indoor growing kit,” she says. “You can order a variety you like and grow it right in your kitchen.”

To The Source

“We work with mushroom farmers all over the country,” says Matt McInnis of North Spore Mushrooms. He’s a co-owner, along with Eliah Thanhauser and Jon Carver, of the four-year-old company based in the Dana Warp Mill in Westbrook.

The three met as undergraduates at the College of the Atlantic in Bar Harbor. “COA is small enough that everyone pretty much knows everyone else,” McInnis says. “The three of us were fairly biology-focused. I got into mushrooms through restaurants–I cooked all through school at the Burning Tree restaurant in Mount Desert. But we all liked to forage for mushrooms in the woods downeast.”

“We’ve got basically two tracks to our business,” he says. “We do spawn, which we sell to other [commercial mushroom] farms. And we also sell mushrooms.”

North Spore mushrooms can be found in restaurants, the Portland Food Co-op, and other retail outlets. “We put out an availability report to restaurants every week, and we have a delivery van.” They also have a thriving mail-order business for indoor and outdoor growing kits, medicinal products, dried mushrooms, and books.

North Spore’s spawning lab is the key to its success. “We had a leg-up because Jon has a graduate degree in mycology. We make master spawn from cells in petri dishes. We have a ‘cell bank’ of familiar and unusual mushroom varieties. I believe we’re the largest specialty spawn producer catering to small growers and home cultivators in the east.”

The Block Farm

Mark Robinson of Cap ’n’ Stem in Gardiner explains his company’s place in the mycological food chain. They buy spawn mixed with grain from North Spore. “First we incubate the mycelium–the part of a mushroom that’s underground–in a temperature-controlled room.”

This incubation room is “four or five thousand square feet. We’ve got about 12,000 total square feet here,” says Robinson. “We’re in an old wool mill that later became a shoe factory. Now it’s home to an commercial bakery and us.” If nothing else, commercial mushroom cultivation seems to rival craft brewing for creative re-use of Maine’s once-abandoned industrial spaces.

Cap ’n’ Stem produces the colonized substrate bricks of  “a mixture of red oak sawdust with different ratios of carbon and nitrogen,” depending on the variety of mushroom. It’s from these bricks that edible, organic mushrooms will grow.

Eliah Tannhauser at North Spore explains, “If this was tomato farming, we’d say we sell tomato seeds. Cap ’n’ Stem would sell the tomato seedlings.”

The substrate medium–grain and sawdust–is sourced from companies in Northern New England. “Our red oak sawdust [is byproduct] from a company operating in Skowhegan and New Hampshire,” says Robinson. Nothing goes to waste. “Once it’s used in our process it can’t be reused in the same way, but we can sell the spent substrate to farmers as a soil amendment that’s high in nitrogen.” After harvesting mushrooms from their bags of substrate, home growers can shake the spent medium right into the compost heap.

Robinson sums up Cap ’n’ Stem. “We’re primarily business-to-business, selling substrate to commercial mushroom farms all over the country.” The company also does retail online sales of shiitake, oyster, and lion’s mane blocks for home growers.

READY TO SHIP

“We have a unique situation with mushroom farming in Maine,” says Aron Gonsalves of Mousam Valley Mushrooms in Springvale. His wife, Emily Sharood, and her family started the company in 2012. “We have strong relationships with the other farmers. North Shore in Westbrook makes the spawn. Cap ’n’ Stem makes the [bricks] and sells them to us, and we fruit them out.”

Or, to complete the tomato analogy, Mousam Valley sells tomatoes.

“We’re shipping about 5,000 pounds of mushrooms a week,” says Gonsalves, “And we expect it’ll be up to 10,000 pounds or more by the end of this year” as the company implements some new production innovations.

Mousam Valley presently employs 15 people and has a fleet of delivery vehicles. “Our biggest business is with grocery stores, from Rosemont Markets to Hannaford.”