Production Mushrooms at Small Fungus Farm

10/19/2013 7:00 AM
By Philip Gruber Staff Writer

OLEY, Pa. — Most people would not be happy if a fungus took over their basement and garage. They certainly would not set up two buildings to nurture it along. But that’s what Joe and Angela Evans did when they started Oley Valley Mushroom Farm.

The couple started out as hobby mushroom growers who also foraged for edible mushrooms in the woods.

After meeting a Washington state mushroom grower at a Penn State conference, they used a plane ticket to anywhere, a wedding gift from neighbors, to go to his farm and learn the basics of mushroom production.

In 1999, Angela Evans suggested they become full-time mushroom growers. Joe Evans had suffered a back injury at his construction job and needed to switch to a different field.

“It was a little stressful” to start the business because money was tight after leaving construction, Joe Evans said. Shiitake mushrooms took more than a year to master, but in time the Evanses got production humming along.

Growing mushrooms is different from other types of agriculture. It starts with mixing the materials the mushrooms will grow in.

“Preparing the substrate takes us hours,” Joe Evans said.

The components of the substrate depend on the type of mushroom. Oak sawdust from a local sawmill is an important ingredient for shiitakes, but various amendments and the moisture content have to be right too. Oyster mushrooms use straw and alfalfa additives.

The Evanses bag the material in special vented plastic bags and steam the substrate for two days to pasteurize it. The steaming happens in a converted milk tank that came from a nearby farmer who got out of dairy.

They seal the bags and inoculate them with purchased spores in a HEPA-filtered flow hood. The filters keep airborne mold spores from getting into the bags. Mold spreads faster than mycelium, the hairy growths of a fungus, and chokes off the mushrooms if it contaminates the bags.

The bags then go to the spawn room in the Evanses’ basement, where the mushroom spores spread throughout the substrate. When the mushrooms “popcorn,” or show tiny bumps, they are ready to go to the grow houses.

The shiitake and crimini grow house is a modified shed, while the other varieties are in a high-tunnel frame with insulated walls and a roof with a translucent center. The buildings have electric, heat and a misting system.

The Evanses start bags every week so that they can have new mushrooms every week during the growing season.

They pick every day, sometimes twice a day during warm months, and usually let each bag go through two fruitings. A mushroom bag can produce five or six fruitings, but the later production is less efficient.

“It’s like most dairies don’t have 30-year-old cows,” Angela Evans said.

Each fruiting takes about five to eight days, but it depends on the temperature.

“They went like gangbusters with the heat” in August, Angela Evans said.

After the mushrooms are picked, they go into the cool storage room. The Evanses try to sell all their produce within a week of picking. Oysters have the shortest shelf life, but shiitakes can go a little more than a week.

Most items only take three days from picking to selling. In busy times, the Evanses may pick before heading to the farmers market later in the day.

“We don’t have the controls the big growers have,” Angela Evans said.

While industrial-scale growers have air conditioning and dozens of workers, Oley Valley has only four employees and is more dependent on outdoor temperatures.

“You can’t let them get overheated. That’s really important,” Joe Evans said.

Keeping the grow room clean is also important, but it is challenging when trying to follow organic guidelines. Oley Valley is not certified organic but uses organic practices.

The main growing season runs from September to mid-May. The oysters start a little earlier, in August. The Evanses cut back to two farmers markets in June.

They do very little with mushrooms in the summer because the mushrooms grow too fast and then have longer gaps in production. Pests and diseases are also worse in the heat. To add variety, they grow berries for the summer markets.

“Our customers understand” the reasons for not having mushrooms in the summer, Angela Evans said.

During the growing season, Oley Valley currently produces about 100 pounds of shiitake mushrooms, 70 pounds of royal trumpets and 50 pounds of oyster mushrooms in a week.

The Evanses are planning to double their production when their niece, Ashley Dietrich, joins them full time. Dietrich’s husband, Tom, will also help part time.

There is enough space in the grow houses to increase the production, but the spawning phase will move out of the Evanses’ basement to the farm the Dietrichs bought four miles away.

Spawning takes up the most space because it is the longest part of the process. Most varieties take four to six weeks from start to finish, with all but a week or two of that time being the spawning phase. Shiitakes hog the most space because they take 16 to 20 weeks from inoculation to harvest.

The expansion should push the yearly production from 4,000 pounds to 8,000 pounds.

The Evanses recently began growing crimini mushrooms and will soon start portobellos. The two mushrooms are the same species but are grown in different ways. The Evanses buy compost for the criminis from Hy-Tech Mushroom Compost in West Grove because zoning laws do not allow them to compost on their property.

Fluffy-looking pompom mushrooms will also be part of their selection this year.

Oley Valley is a very small mushroom grower, especially compared with Kennett Square producers — one of those produces 11 million pounds annually, Joe Evans said — so Oley Valley’s marketing is much different from the large producers’ as well.

The Evanses primarily sell through five farmers markets: Downingtown, Malvern, Phoenixville, West Chester Growers Market and The Artisan Exchange in West Chester.

“If people like mushrooms, they seek me out. They come in the rain,” Angela Evans said.

Oley Valley also supplies CSAs and a few restaurants. When the Evanses started the business, they sold mostly to chefs, whose requests helped shape the selection of mushrooms they grow.

The Evanses hope to increase restaurant and CSA sales in the coming year as they ramp up production.

Even when chefs use a different vendor during the summer, they start using the Evanses’ produce when they start growing again in the fall, Joe Evans said.

Oley Valley mushrooms have also been featured in special events at the James Beard House in New York City, Eckerton Hill Farm in Lenhartsville and SouthWark restaurant in Philadelphia.

One of the most common questions farmers market customers ask is “What do I do with them?” Joe Evans said.

“A lot of people weren’t really raised eating mushrooms except for maybe mushroom soup,” Angela Evans said.

Most consumers are not exactly afraid of eating mushrooms, but eating a fungus can be a mental hurdle.

“They think it’s weird,” she said.

The Evanses often use taste tests to encourage customers to try the specialty varieties like pompoms. Once customers try an unfamiliar kind, they often purchase that kind.

People especially want recipes and ways to cook with mushrooms. Joe and Angela Evans help with that now, but they expect Ashley Dietrich, their niece, will have a bigger role in that part of the business when she joins them full time.

Ashley Dietrich likes to cook and is good at writing down what she made, which will help customers. She will also be doing more with online marketing. “I think she will be good for our farm,” Angela Evans said.

Mushrooms are nutritious and have minerals that vegetables do not, Angela Evans said. Their high protein levels make them good meat alternatives for vegetarians, and mushrooms are recommended in cancer diets.

Each type of mushroom has different nutritional properties, so it is also best to eat a variety rather than just one kind.

Shiitakes, portobellos and royal trumpets are “as different as broccoli and carrots and string beans are different,” Angela Evans said.

Despite their small production, the Evanses have enjoyed considerable recognition at the Pennsylvania Farm Show, where most of their competitors produce mushrooms in far larger quantities than they do.

Oley Valley entered five categories this year and earned four first places and a third place.

They have generally placed third overall because they have not entered every category. Next year, they plan to add criminis and portobellos to their entries, which could help their overall placing.

“We’re like flies and elephants,” Angela Evans said, comparing her farm to the mammoth mushroom producers.

While Oley Valley’s smaller size puts supermarket shelves out of reach, the smaller scale makes it easier to control the mushrooms and the growing environment, Joe Evans said.


Has the Food and Drug Administration done enough to revise its produce safety rule?

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