KENNETT SQUARE, Pa. -- The Brandywine Valley near Philadelphia is horse country, with dozens of riding stables, breeding farms and training facilities. But in this bucolic hamlet in the heart of Chester County, it's mushrooms that rein -- make that reign -- supreme.
And we're not just talking the familiar white button mushrooms, Agaricus bisporus -- though with 60 local Agaricus growers each year producing 340 million pounds of buttons, that's certainly worth noting. Less than a mile from town, Phillips Mushroom Farm distributes some 35 million pounds of specialty mushrooms annually. Those are the funny-looking ones with the hard-to-pronounce names: shiitake, crimini, maitake, enoki.
Ever want to try growing your own at home? The Mushroom Cap in Kennett Square (1-610-444-8484; themushroomcap.com) carries kits from local farmers ($29.95 for white or portobello) while California-based Mushroom Adventures (1-530-741-2437; www.mushroomadventures.com) sells six different kits, including blue oyster and crimini, ranging in price from $33 to $39.
-- Gretchen McKay
With so many fields this time of year full of corn stalks, corn might seem to be Pennsylvania's signature crop. Yet mushrooms actually are a bigger business. The state this year accounted for 63 percent of the 793 million pounds of white and brown Agaricus mushrooms grown annually in the United States, according to federal statistics released Friday, contributing more than $453 million to the economy. So many edible fungi are cultivated here, in fact, that it helps make hay grown by local farmers -- used as a substrate in mushroom farming -- the state's No. 2 cash crop, says Phillips' general manager Jim Angelucci.
The industry has come a long way since its birth in Kennett Square in the late 1890s. Back then, mushrooms were grown only -- with great difficulty, because the spores are so fragile -- during the winter because no one had yet figured out how to control climate. (Most varieties of mushrooms require growing temperatures of about 60 degrees.) Those first farmers also grew only white mushrooms, and most of those, says Mr. Angelucci, were sold processed rather than fresh.
Phillips' founder William W. Phillips' experiments in the late 1920s -- using ice and then air conditioning to cool growing houses in summer -- changed all that. Suddenly, mushrooms could be cultivated year-round. By 1930, Chester County boasted a whopping 350 mushroom growers, and Kennett Square, where the majority were located, was crowned "Mushroom Capital of the World."
That number has dropped dramatically; today, Pennsylvania counts just 69 Agaricus mushroom growers and a handful of specialty growers. But many of those are bigger and more technologically advanced than ever: Phillips, the first to successfully grow shiitakes indoors on sawdust logs, has invested millions on more than 1 million square feet of growing space. Today, they grow nine varieties of fancy fungi.
Exotics are still very much a niche market in the U.S.; just 10 percent of mushroom eaters buy them on a regular basis. But demand is slowly growing. Sales of shiitake mushrooms are up 42 percent from last season.
The modern standard for growing mushrooms is the Pennsylvania "double," a windowless, chilly concrete building that's built into the side of a hill. At Phillips, the ones used for growing crimini and big brother portobello mushrooms -- more flavorful cousins of the white button, which the company stopped growing in 1989 -- each hold 24 beds measuring 5 1/2 feet by 60 feet and stacked six deep, like bunks.
You might think they're meant just for salads or sauces, but fresh mushrooms actually are pretty versatile. They're also low-cal and fat- and cholesterol-free, high in niacin and fiber and many contain riboflavin and B vitamins.
Opinions vary, but Jim Angelucci of Phillips Mushroom Farms insists only three varieties should be eaten raw: white button, brown crimini (also known as baby bellas) and enoki.
Look for those with a fresh, smooth appearance and dry surface. All mushrooms are best used immediately but will keep up to a week in the refrigerator; just be sure to store any unused portions in a paper bag instead of an airtight container or plastic.
Never soak fresh mushrooms or leave them sitting in water, as they are extremely porous. Instead, clean them by wiping gently with a damp paper towel or brush. Mushrooms don't need to be peeled, but you may trim the stem end if it's dry or tough.
Mushrooms grow from "spawn," microscopic spores that have been bonded to rye seeds or other grains and folded into a pasteurized growing medium, or substrate. (Mushrooms lack chlorophyll, so you need to provide a nutrient-dense food source.) To ensure the compost surface or spawn don't dry out, the beds are covered with plastic, lights are turned off and the temperature is maintained at 75 degrees. Eighteen to 21 days later, the compost is filled with what look like roots -- lacy white filaments called mycelium.
A 2-inch layer of pasteurized peat moss, called casing, is spread on top, and when the surface is covered with mycelium 10 days later, the temperature and carbon dioxide level are dropped, and the humidity level raised with watering. Eventually, tiny white baby mushrooms, or "pins," push through the casing. A few days later, the first of three "flushes" is ready to be harvested; once the mushrooms start growing, they can double in size overnight. A second and third flush follow after a lull of five to seven days.
After the mushrooms are picked, the growing room is closed and pasteurized with steam for 36 hours, then cooled and steamed again to destroy pests or bacteria. Then the 11-week process begins again.
It's a process that takes a lot of science and attention to detail but produces great results; portobellos, which Mr. Angelucci says the company once had to give away, are now its most popular mushroom.
The more exotic-looking mushrooms, spread out among the farm's equivalent of 120 growing rooms, each are cultivated a little differently. Velvety, fan-shaped oysters, for instance, grow in clusters from holes poked into the sides of long, tubular plastic bags filled with a substrate made of pasteurized cotton seed hulls; the long-stemmed enoki and beech climb out of the tops of plastic bottles. Shiitake mushrooms, originally cultivated on natural oak logs and harvested every two to four years, are grown on 2-pound manmade oak "logs" (actually, long plastic bags filled with red oak sawdust, wheat grain and millet).
Phillips also grows maitake, known as sheep's head or the "dancing mushroom" because when fungi foragers find it in the wild, "they dance because they're so happy," says Mr. Angelucci. Prized for its nutraceutrical properties, it boasts clusters of chocolate-brown petals on a central stalk, giving it the look of coral. Even more beautiful, and unusual, is the pom pom. It has a mild, sweet taste that's similar to scallops.
While most of the growing practices at Phillips are modern, harvesting is still done by hand.
And what's harvested today, notes Mr. Angelucci, is in stores tomorrow.
Gretchen McKay can be reached at email@example.com or 412-263-1419. First Published August 28, 2008 4:00 AM