Posted May 1, 2011
If you spent your childhood locked in a dark room you’d be craving a tan, too. But that’s not the reason Ostrom Mushroom Farms is exposing its fungi to ultraviolet light.
It turns out that a quick run through the fungus version of a tanning salon causes ordinary white button mushrooms to produce vitamin D — just as people do when exposed to sunlight. The nutrient keeps our bones strong and fights disease.
Ostrom’s began producing the product in February. A 3-ounce serving provides the daily recommended allowance for vitamin D (400 IU). Other dietary sources of vitamin D include fish and milk. Currently, the company is offering the product only in its sliced white mushrooms.
Ostrom’s gave a tour of the plant and the vitamin D process to local media in early April. The sprawling facility is across from Nisqually Middle School at Mushroom Corner near Lacey.
The new product is a rare development for the company which sticks to its longtime white and brown mushrooms. Young brown mushrooms are marketed as Crimini while the mature, saucer-sized varieties are called portobellos.
“You can’t have too many diversions” when it comes to growing mushrooms, said company co-owner Bill Street. He bought the mushroom farm from Green Giant in 1964 when it focused on canned mushrooms. Street soon found himself priced out of the market by Asian producers and switched to the fresh mushroom market.
Science has led to improved growing methods, Street said. His farm, which once produced six pounds of mushrooms per square foot annually, now produces 30 pounds in the same space and time. They sell about half to retail outlets and the other half to food service companies.
Sliced mushrooms have been increasing their share of the market and sales of brown mushrooms have been increasing seven to 12 percent annually for the past three years, said Fletcher Street, director of marketing and sales. “Mushrooms are coming in to their own,” she said.
During the tour, the Streets (father and daughter) offered some consumer tips. Criminis are the better buy, they said, being more dense and more flavorful. They cost more to produce but grocery stores sell them for the same price as whites.
Mushrooms, being fungi, are ripe from day one — long before they are harvested. When a mushroom opens its gills it loses moisture (so you pay for less water and more fungus) and the flavor intensifies. However, its shelf life is shorter than an unopened version and must be used sooner. Mushrooms should be stored in a paper bag or other dry environment in the refrigerator. If they should get slimy toss them out.
Plant operations manager Gary Marzetti led the tour through dark and dripping rooms, each growing mushrooms of various sizes and ages. The process — in a nutshell — begins with wheat straw and dried poultry manure that has been composted for 18 days and sterilized at 180 degrees. It’s then mixed with mushroom spore inoculated grain.
The compost looks and almost smells like a rich pipe tobacco when it goes into trays on massive shelving units. After a few days a network of white veins begins to show up in the material — mycelium. Soon, mushrooms, the fruiting bodies of the mycelium, show up. From there on they double in size every 24 hours. The growing process takes four weeks.
For the vitamin D enhanced product Ostrom’s is taking advantage of a natural substance mushrooms produce, ergosterol, that converts light into vitamin D. The mushrooms get exposed by about a dozen pulses of the UV light just before slicing and packaging. The company hopes to offer vitamin D-enhanced portobellos in the future.
Craig Sailor: 253-597-8541 craig.sailor@thenewstribune.com
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Copyright © 2011, The News Tribune, Tacoma, Wash.
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