by Kristen M. Castrataro
Growing in a damp forest understory, emerging from the sides of stately trees, or showing up in brilliant colors on the side of a walking trail, mushrooms are a miracle. Their colors, shapes and sizes are almost as limitless as their flavors. Golden Oysters brighten the palate, tasting as sunny as they look. Blue Oysters are subtle and mild, a mushroom for people who think they dislike mushrooms. For the best in these, and so much more, the RI Mushroom Company in South Kingstown, RI is the place to go.
The RI Mushroom Co. makes its home in a warehouse on a nondescript suburban side street. Inside the warehouse sits an office, a laboratory, three 16×50 ft. greenhouses, a walk-in cooler, and a packing area. The real standouts, however, are the three men behind RI Mushroom Co.: Bob DiPietro, Mike Hallock and Todd Leftwich.
Bob DiPietro’s history with mushrooms began in the kitchen. For 30 years he worked in the restaurant business. He never considered growing mushrooms until he hired someone to do work on his home. After work one day, Bob invited the man to dinner and learned he had farmed mushrooms in Oregon. Bob was fascinated by the process and decided he might want to try it himself.
Bob and a partner started at a local farm, where an 8×8 ft. room became the first home of RI Mushroom Co. A short time later Bob’s partner had to abandon the project, so Bob started looking for a new partner. At a farmers market, he met Mike Hallock.
Mike is a Berkeley-trained guitarist who turned to farming after working for Sony Music. It was at various farms that he learned about growing mushrooms and entertained an interest in starting his own business.
The timing could hardly have been better. Bob had a pilot program going and was looking for a partner; Mike wanted a farm. They joined forces and in January of 2013 they incorporated. They started selling in April. Their basement lab was a good place to begin, but it had its challenges. Their first summer was a Rhode Island scorcher, and one morning they walked in to a scene “like someone took a yellow paint bomb and exploded it in the room.” The Golden Oyster Mushrooms had proliferated overnight beyond anyone’s expectations.
Bob and Mike overcame many challenges, and within six months they had outgrown their incubator space. They moved to the current location and put up their first interior greenhouse, continuing to learn by trial and error. One lesson learned involved the sometimes-complex relationship between different mushroom varieties.
They were growing Golden Oyster and Blue Oyster Mushrooms in the same house. The Golden Oysters were thriving, but the Blue Oysters were standing still. They realized the difficulty lay in the orientation of the mushrooms within the house. The Blues were closest to the HVAC intake, meaning the air circulated across the Golden Oysters before reaching the Blues. Golden Oysters are vigorous sporulators (as demonstrated by their explosion in the Sweet Berry Lab). When exposed to the Golden spores, the Blue Oysters, rather than trying to outcompete the Goldens, refused to sprout and waited for a more favorable environment with less competition. By switching the location of the varieties, both thrived. They are now able to grow them in separate houses to eliminate the issue altogether.
In 2014 they received a grant under Rhode Island’s Local Agriculture and Seafood Act (LASA), which enabled them to put up two additional greenhouses, triple their production, and land accounts with a few large distributors.
A year and a half ago, RI Mushroom merged with Nantucket Mushroom Company and added their third partner, Todd Leftwich. Todd is a self-taught mycologist who founded Nantucket Mushroom Company in 2007. His specialty is selectively breeding. At this time, the team is in the test phase of a breeding program for local wine caps. Although they do not expect a large harvest with this crop, they hope to eventually develop a high-yield strain.
The breeding process begins in a state-of-the-art lab with a laminar flow hood. When operating, the unit creates a sterile workplace that ensures the farmers are reproducing only the organisms they want to reproduce.
The spawn is placed in perforated grow bags with a medium appropriate to the particular variety and stored in the spawn room. They remain there until the mycelium runs through the bags and the mushrooms “pin,” or emerge from the holes in the grow bags.
At this point, the bags are moved to the grow room. The environment is critical in growing mushrooms. The DNA of each particular type of mushroom is identical, but the final product varies greatly in size, appearance and flavor depending upon its location in the house, growing medium and the climate.
The importance of environment was demonstrated recently with a batch of shimeji (beech) mushrooms. The mushrooms were not growing as expected, so Bob and Mike set them in the back of the house and ignored them. When they finally re-discovered them in the bag, they had grown incredibly large and deformed from the high CO2 levels. Interestingly, the flavor was delicious, and the chefs loved them. It may have turned out to be a fortuitous “mistake” . . . if it can be duplicated.
Not every oversight turns out so propitiously, so controlling the climate is one of the reasons Bob and Mike chose to place their greenhouses inside the warehouse. The conditions in the warehouse remain relatively stable as opposed to those in the outside environment.
The fungi reproduce very quickly—the entire process from spawn to fruiting can take as little as six weeks. The mushrooms are in the grow room a matter of days before they are ready for harvest, and they are harvested twice a day.
They also source exotic mushrooms from Italy, France, Bulgaria and many other locales. Because many of those producers are not organic, the cooler is divided into an organic and non-organic side. For their certification, meticulous record keeping is a must.
Whether organic or non-organic, domestic or imported, RI Mushroom Company’s mushrooms enjoy a high turnover rate. Homegrown mushrooms are in consumers’ hands within two to three days of harvest versus up to a week for those in most grocery stores.
RI Mushroom Co. sells directly to restaurants, CSA’s and farmers’ markets. They also enjoy the support of their fellow business owners. They obtain spent brewer’s yeast from the microbrewery next door and sawdust from a local woodworker.
Exemplifying that cooperative spirit, RI Mushroom Co. has a culture of giving back. Their used bags get sent to a start-up composting facility. They are also helping out a local student with his school project by growing a batch of mushrooms that will glow in the dark. They are starting spawn for a project in a forest in South County, RI. They even recycle 50 percent of their own growing media.
With the incredible success they have attained in such a short period of time, I asked Bob what his goals were for the future. “To sell more mushrooms,” he replied. One area they are exploring is value-added products. They have already collaborated with a variety of local businesses and individuals on test batches of several products; they now need to pursue funding for the next stages. With their track record, I would expect to see a line of RI Mushroom Co. products on shelves soon.
RI Mushroom Co.: “Growers and purveyors of exotic mushrooms”
by Kristen M. Castrataro