Mile High Fungi Spawns a Growing Mushroom Business

So many shiitake mushrooms.EXPAND
So many shiitake mushrooms.
Linnea Covington
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Running a mushroom farm isn't too different from owning a fruit or vegetable farm, according to Liz and Michael Nail of Mile High Fungi, on the outskirts of Littleton.

"It's a lifestyle choice, and we can handle the time commitment and long summer hours if we take a break in the winter," says Liz, adding that they don't grow the mushrooms in the colder months so that they can both get some rest and not have to worry about making deliveries in snowy weather. And while Mile High Fungi is much smaller in physical size than a conventional farm, it's just as busy during peak growing season.

Liz Nail processes shiitakes at her mushroom farm, Mile High Fungi.EXPAND
Liz Nail processes shiitakes at her mushroom farm, Mile High Fungi.
Linnea Covington

Every day of the week, the Nails get up before dawn to harvest mushrooms and complete the morning chores at their farmhouse: feeding animals, milking goats and getting ready for the day. Their goal is to get it all done before the arrival of the 9 a.m. crew, a hodgepodge of temporary employees who help on the farm and work on the farmhouse itself, which has been a spectacular project since the couple moved onto the property four years ago.

When the Nails bought the land, there were no buildings, so the barn (where the mushrooms are grown), the house and the goat and donkey pens had to be built. First came the barn, decorated inside with pine boards and string lights so that it feels almost like a cozy hipster hideaway. But then you see the rows and rows of beautiful mushrooms in blocks of soil, promising flavorful additions to the table down the line.

The official Mile High Fungi barn.EXPAND
The official Mile High Fungi barn.
Linnea Covington

There are three doors leading to the mushroom fruiting rooms, dubbed Larry, Pearly and Moe. Inside each, floor-to-ceiling shelves contain bags filled with what looks like brown dirt. It's actually a special mixture of hay, sawdust, wood chips and other organic material called substrate. The Nails mulch together their own substrate and stuff it into Unicorn Bags, a brand of breathable plastic sacks many professional mushroom farmers use these days.

The bagged substrate goes into an autoclave for sterilizing with low heat and steam, much like a giant pressure cooker. The chamber, which Liz designed and built, has colorful wood panels artfully placed around a large, vault-like dial that seals the bags inside.

Once sterile, each bag of substrate goes into the lab, where the Nails don hair nets and face masks while  inoculating the substrate with the appropriate mushroom spawn, be that golden oyster, black pearl, shiitake, trumpet, chestnut, lion's mane, blue oyster, phoenix oyster or maitake. Most of the mushroom spawn comes from outside suppliers, though the Nails have been experimenting with methods for using their own mushrooms to start new growth.

Lion's mane mushrooms pop up in the farm's fruiting room.EXPAND
Lion's mane mushrooms pop up in the farm's fruiting room.
Linnea Covington

"There's not a lot new in the mushroom world; they are generally the same tried and true staples, since there are only so many you can grow," Liz notes, though she says she's excited to see how the new black pearl mushrooms come out.

The blocks of inoculated substrate go upstairs to sit on shelves, where the first stage of growth begins. At this point the mushroom bags still look like dirt in plastic wrap, but as the spawn begins to grow, the appearance becomes whitish, like moldy sawdust. Once their appearance becomes cloudy and "dusty," it's time to move the substrate into a fruiting room.

Trumpet mushrooms growing from their bags at Mile High Fungi.EXPAND
Trumpet mushrooms growing from their bags at Mile High Fungi.
Linnea Covington

Here the temperature and humidity are kept consistent, making the perfect environment for fungi to grow. The bags get cut with an X across the top, and then the Nails just have to monitor the bags and wait. Some mushrooms, like the oysters, grow fast and are ready to harvest within a week. Others, such as the chestnut, can take double that time. But regardless of the variety, there's always enough growing that the Nails have to harvest every day, getting about a pound of edible mushrooms from each five-pound block of substrate.

"What the mushrooms grow on is entirely organic, and one day we might even pull the trigger and get certified as organic," says Liz. But for now, she adds, the process to become an organic farm is too much to add to their already busy schedule.

For the past six year, the Nails have been growing mushrooms, but that wasn't the original plan. The couple met at Evergreen State College in Olympia, Washington. After school, Liz, who grew up in Morrison, had wanted to come back home to Colorado.

Mile High Fungi is a common farmers' market stop for chefs.EXPAND
Mile High Fungi is a common farmers' market stop for chefs.
Linnea Covington

"One day I woke up and said, 'Why don't we sell mushrooms?'" she recalls. The couple had been learning about sustainable agriculture in school, she continues, adding, "At the time, there wasn't anybody doing mushrooms in Denver, and locally it was just Hazel Dell [in Fort Collins]."

Michael, who's from Maryland, liked the idea, so the couple moved to Denver and officially started Mile High Fungi in 2014. Their first farm was located in a shipping container in their back yard near West 20th Avenue and Federal Boulevard, where they were living at the time. It was small compared to the current setup, but at that time, Mile High Fungi was a word-of-mouth, low-key business. It wasn't until 2015 that the company really started taking off, selling to restaurants across the metro area, adding to CSA boxes and peddling mushrooms at farmers' markets.

Now the operation produces about 750 pounds of mushrooms a week, even after COVID-19 and the restaurant shutdown put a damper on business.

The Nails wear masks in the fruiting room at Mile High Fungi.EXPAND
The Nails wear masks in the fruiting room at Mile High Fungi.
Linnea Covington

To counteract the sudden lost contracts Mile High Fungi had with restaurants and the abundance of mushrooms ready for harvest for those restaurants, the Nails rallied and started up their word-of-mouth business again. This time they drove all around the city delivering pounds of plump shiitakes, meaty trumpets and nutty chestnuts to fans. The Nails also got their mushrooms into more CSA boxes, one business that has expanded as grocery shoppers have sought out no-contact solutions.

Beautiful chestnut mushrooms from Mile High Fungi.EXPAND
Beautiful chestnut mushrooms from Mile High Fungi.
Linnea Covington

Delivering the mushrooms themselves was tiring, says Liz, so they stopped that service once the markets opened up at the end of May and beginning of June. Now they peddle their crop of fungi at farmers' markets, including Highlands Square, Union Station and Pearl Street. Mile High Fungi can also be found in CSAs from the Denver Botanic Gardens' Chatfield Farm, Go Farm, Sprout City Farm and ACRES at Warren Tech. While selling the mushrooms in bulk compared to marketing them to restaurants makes more money for the farm, Liz says she misses seeing what amazing things chefs are doing with their products.

So for now, it's up to home cooks to showcase the mushrooms with their creative culinary skills. After all, the possibilities on the dinner plate are seemingly endless. From fried to grilled to roasted, in tacos and pastas or  on flatbreads and pizzas, you can be your own chef with Mile High Fungi's delicious, versatile and fun products.

Cleaning up shiitakes for customers.EXPAND
Cleaning up shiitakes for customers.
Linnea Covington

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