In a building attached to the back of Ernie’s Pool and Darts on Forest Avenue, three friends are trying to fill a niche that’s been missing in Portland’s local food movement.

Khanh Le was the first of them to notice it.

After moving to Portland for its reputed food scene, he realized restaurant menus and farmers markets rarely carried local mushrooms. A financier by trade, he saw a potential venture.

It turns out he wasn’t the only one with that thought.

Within the past year or two, Le and his crew, a family in Springvale, old high school classmates in Warren and forager friends in New Hampshire have all started indoor mushroom farms after discovering an unfulfilled demand for locally grown specialty varieties that are available year-round.

Last month, a Portland architect received a special exemption from the Westbrook Planning Board to grow culinary mushrooms in a former flea market building at Prides Corner.

Although foragers have long supplied wild Maine mushrooms to Portland restaurants and retailers, the fungi are only available from spring to fall and, even then, are subject to the weather. The fickle fungi also have a short shelf life, so quality is lost when they come from away.

In climate-controlled buildings, mushrooms can grow anywhere all year, though it’s more expensive in colder weather – possibly the reason few in Maine have embarked on it until now.

Candice Heydon is the exception.

“When I started selling shiitake and growing it, people couldn’t pronounce the word,” said Heydon, owner of the Oyster Creek Mushroom Co. in Damariscotta.

That was 25 years ago, when she was clearing land to build a house and found out the University of Maine Cooperative Extension was offering a class on growing Asian mushrooms on oak – the very type of trees she was cutting down.

After taking the class, the longtime waitress and cook decided she was sick of working for other people and would start her own business growing mushrooms.

“I was the only one for a while,” said Heydon, who annually sells about 40,000 pounds of mushrooms, which she grows herself and buys from other farms and foragers.

Will Manahan and Jon Vickerman, a boat-builder and cook who met at Medomak Valley High School in Waldoboro, are among her newest sources.

Last year was the first full year in operation for their Pleasant Mountain Mushroom Farm, which produces between 30 and 50 pounds of Italian oyster mushrooms a week, Manahan said.

That’s enough to supply a couple of farmers markets and a few area eateries, including Rockland’s renowned farm-to-table restaurant, Primo.

“Whatever we grow we have no problem getting rid of,” Manahan said.

They hope to expand beyond his mother’s land in Warren and eventually work on the farm full time.

In Portland, Le and his friend Scott Payson’s Bountiful Mushrooms Farm is already supporting one full-time employee, mushroom-growing guru Devin Stehlin. Le and Payson have kept their day jobs.

Payson said the business has just started breaking even, and the owners expect to start recouping some of their investment later this year.

He said they probably could have gotten the farm up and running for under $100,000 – if they’d known what they were doing. Instead, he said, there’s been “a lot of trial and error.”

The urban farm is now producing 300 to 600 pounds a week of shiitake, oyster and lion’s mane mushrooms, which sell for $8 to $12 per pound. The growing process, in which they mix mushroom spawn in plastic bags of either sawdust or straw and place them in humid tents, takes between two weeks and two months, depending on the variety.

But harvesting happens daily, as does delivery of the mushrooms, which are on menus at 16 local restaurants.

Local 188 in Portland was the company’s first customer. On a Tuesday afternoon last month, Payson brought paper bags filled with more than 6 pounds of mushrooms into the Congress Street restaurant.

Before he could get them to the walk-in refrigerator downstairs, chef and owner Jay Villani grabbed a bag of golden oysters and ripped it open. He would be keeping them in the kitchen with him.

“I’ll use these for the risotto tonight,” he said.

Villani said he had been getting mushrooms from a farm in New Hampshire, until it shut down. He’s been using Bountiful Mushrooms since a sample bag showed up in his restaurant last year.

“It’s just nice to have a constant supply,” he said.

Because the owners of Bountiful Mushrooms Farm brought samples to all their favorite spots, their customer base grew and now ranges from Portland fine-dining mainstay Fore Street to Alewive’s Brook Farm in Cape Elizabeth, which sells the mushrooms at farmers markets.

“When we sell out or don’t have them for a day, people are always looking for them,” said Caitlin Jordan of Alewive’s.

Le said he isn’t concerned about competition from the yet-to-open Westbrook farm, which owner Christopher Campbell declined to discuss.

“We think that there’s plenty of demand in this area,” Le said.

Between the growing appetite for all things local and increasing interest in eating healthy, specialty mushrooms have found “a rapidly growing market,” said John Sharood, chief operating officer of Farming Fungi in Springvale.

Specialty mushroom production neared about 20 million pounds and sales were valued at about $65 million nationwide in 2012-2013, up from 13 million pounds and $34 million a decade earlier, according to the U.S. Department of Agriculture.

A report by the Mushroom Council, a promotional and research board established by Congress, showed that between 2006 and 2012, specialty varieties accounted for an increase in the incidence of mushrooms on restaurant menus in the U.S. While garden-variety white button mushrooms remained in about 80 percent of restaurants, matsutakes, black trumpets, truffles and criminis doubled in popularity.

Sharood said Maine, in particular, has “a large number of highly sophisticated consumers that like organic and specialty foods.”

Farming Fungi, which he started with his son and daughter, is the state’s only certified organic mushroom farm and has grown at least nine different varieties, including pioppino and chicken of the woods.

Sharood wouldn’t reveal the company’s current yield, but said the goal is to soon be producing more than 1,000 pounds a week and serving markets from Montreal to Connecticut.

Under the Mousam Valley Mushrooms brand name, the company is selling to six restaurants and small stores in York County, as well as Hannaford supermarkets in Portland, Scarborough, Kennebunk and soon Sanford.

The Scarborough-based grocery store chain offers a lot of opportunity for expansion. Hannaford’s sources for mushrooms vary from store to store, but most come from Pennsylvania and California – the country’s hotbeds of mushroom farming.

Eric Blom, a spokesman for Hannaford, said the company is constantly trying to increase the number of local vendors it uses and would gladly add more mushroom growers.

“We’re always looking,” he said.

Food sellers aren’t the only potential customers for mushroom farms, according to Eric Milligan, an owner of the New Hampshire Mushroom Co.

The Tamworth, N.H., business, which started growing in late 2012, has begun producing medicinal mushrooms, in addition to the rotation of about 10 culinary varieties it sells to more than 100 restaurants in New Hampshire and Massachusetts, as well as seven wholesalers, including Native Maine Produce.

Milligan started the farm with two fellow foragers who decided to take their hobby and try to turn a profit. They’re almost halfway to their goal of producing 2,000 pounds a week by this summer. Within four years, they plan to expand their weekly output to between 10,000 and 50,000 pounds.

Milligan sees endless uses – and markets – for his mushrooms, from producing biofuels to cleaning up oil spills.

“They are all ways we believe mushrooms can be used to help save the world,” he said.

Leslie Bridgers can be contacted at 791-6364 or at:

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@lesliebridgers