There are mushrooms growing in Rob Gianadda’s basement, but he’s not calling a plumber. Instead, the Elmwood Village man is calling top Buffalo chefs.

Those are gourmet oyster mushrooms he’s got down there, some as big as dinner plates. Gianadda’s Flat # 12 Mushrooms company sprouted into existence six months ago, as he joined a small crew of artisanal producers providing carefully grown ingredients to Buffalo restaurants that are willing to deal with a tiny supplier for picked-that-day freshness.

Bistro Europa, Kaydara Noodle Bar, Rue Franklin, Vera Pizzeria and Black Rock Kitchen and Bar are all Flat # 12 customers. “You pay the same price for them as for farmed mushrooms, but I really like their quality,” said Karl Wyant, Vera’ chef.

Wooly bearded and tattooed, Gianadda lives off Elmwood Avenue with his wife, Kari, and 5-year old daughter, Clementine. He began growing mushrooms as a hobby in 5-gallon buckets of spent coffee grounds from Spot Coffee.

The family enjoys do-it-yourself projects and started out buying growing kits, walking a few blocks to Spot for the buckets and then adding the mushroom spores to the coffee. Three weeks after their first try, three mushrooms appeared, Gianadda recalled. “My daughter thought it was really cool.”

These days Gianadda uses straw, called “chaff” in mycological lingo, as a growing medium. He inoculates it with oyster mushroom spores and keeps everything moist with controlled amounts of water.

Oyster mushrooms can be found growing on fallen logs in the forest, and they have been cultivated by humans for centuries. Bigger than typical fungi at the grocery store, Gianadda’s are carefully harvested to retain the whole stalk. The entire mushroom can be used to make soup stocks, he said.

The flavor is more intense, “more natural” than commercially farmed mushrooms, Gianadda said. Delivered right after harvesting, his mushrooms don’t endure days or weeks in shipping containers like supermarket specimens can.

Gianadda likes to smoke them for a short time – or even cook them with water and a tiny squirt of liquid smoke – to bring out their earthiness.

Flat #12 doesn’t produce enough mushrooms to sell directly to the general public yet, but lucky diners can sample Gianadda’s mushrooms at one of a growing number of Buffalo restaurants. That’s partly because Gianadda is an unabashed foodie who loves all things pork and dines out regularly. He also has an apparent knack for making culinary connections in town. When he and Steve Gedra of Bistro Europa started chatting one night, Gianadda mentioned his basement’s dark secret.

Gedra offered to buy every mushroom he had, and since then the business has been growing like, well, mushrooms: slowly, steadily.

After Gedra’s nudge, Gianadda started growing more fungi for restaurants. Rue Franklin and Europa often pickle their mushrooms; Gianadda said his mushrooms are excellent candidates for pickling and will take on flavors of bacon fat, flavored oils or broth. “Once you get to the cooked point, it releases it back to the dish,” he said.

Kaydara, located on Main Street in downtown Buffalo, is Gianadda’s biggest customer. Chef 2/2 (“Tutu”) Inthalasy buys 12-15 pounds of mushrooms every week for his broths, side dishes and stir-fries. On May 21, the restaurant threw an eight-course, all-mushroom dinner that featured Flat #12. It sold out quickly, and Gianadda had a blast.

At Vera, Wyant serves them in a risotto with pecorino, prosciutto and asparagus and on a pizza with gruyere, smoked ham and garlic oil. He plans to incorporate more into his summer menu and daily specials.

Oyster mushrooms are great for sautéing and roasting, and their flavor is sweet and mild, Gianadda and Wyant agreed.

The mushrooms can turn out different colors depending on the temperature at which they are grown. In cooler weather they are gray and blue, but will turn a golden yellow, or even pink, if the temperature goes up to 80 degrees, Gianadda said.

JJ Richert of Torches and Smoke on the Water is the next chef in line for Flat #12 – once Gianadda can figure out how to ramp up production.

“It’s becoming harder to do,” he said. Space, not time, is the problem. “At first my goal was semi-hippie: Get a carbon-neutral growing area and use all-local shipping. I’m using a sonic mist fogger to create a mist in the grow room, which can run forever on little electricity.”

As his fungi farm grows, he is also scouting a larger facility. “I was drawn to urban farming, and Buffalo has vast amounts of warehouse space.” He said he was lucky that his basement, which was built in 1910, had the right dampness to grow oyster mushrooms.

The low energy footprint also appealed to Gianadda. Along with the mister and a large steamer that pasteurizes the straw, he uses the humidity and natural air flow downstairs to regulate temperature, which the mushrooms appreciate. He’s looking into using solar power to run the water and other controls.

“I like that I can make something out of nothing,” he said.

Inoculation of the mushroom spores takes 10 days, then another 10 to 14 days in a “fruiting chamber” until the baby mushrooms appear. Gianadda supplements the chaff and straw with construction waste from a local recycling company that grinds gypsum and hardwood. The gypsum stabilizes the chaff’s pH, which helps the mushrooms thrive.

He’s also starting to use hardwood sawdust to grow other mushroom varieties, like enoki, king trumpets and mushrooms with medicinal properties. “I’m interested in trying the Japanese reishi, which can be dried and ground for tea or medicinal caplets … you name it, I’ll give it a try,” he said.

“It would be great if I could get to the point where I could sell a really great product, and keep it urban and local.”

According to Steve Gedra, Gianadda’s nearly there. “Robbie is a great regular and his fungus is bomb. I’ve been using him for a few months now,” he said.

Gianadda plans to perfect his technique for another year, set up a seasonal schedule and poll his customer base to determine what kinds of mushrooms are in demand.

“It’s special when you can get something in season,” he said. “It’s nice when you don’t get everything you want all the time.”