by Greg Marley
PORCINI RISOTTO
This dish is generally made with dried porcini, either yours from the last season’s harvest or those purchased at a specialty food store. A little dried porcini goes a long way. I make the entire dish in a 4-quart enameled cast iron Dutch oven. The added fresh mushrooms are a great finish and do not need to be porcini; many cultivated or wild species will do nicely.
1 ounce dried porcini
2 cups hot water
3–4 cups chicken or other flavorful stock
Salt and freshly ground pepper
¼ cup good olive oil
1 medium onion in ¼-inch dice or 1 medium shallot, minced
2–4 garlic cloves, minced
2 cups Arborio rice (7 ounces)
½ cup dry white wine
2 tablespoons butter
1 cup freshly grated Parmigiano-Reggiano cheese (or mix with Romano cheese)
1 pound fresh porcini or crimini mushrooms, thinly sliced (optional)
In a medium bowl, cover the dried porcini with the hot water and let sit 15 minutes to reconstitute the mushrooms.
Remove the porcini and chop coarsely; add the soaking liquid to the stock to make 4 cups.
Heat the stock and the reserved soaking liquid in a separate saucepan to almost boiling.
Heat oil in the Dutch oven, add the onion, and sauté until translucent (5–6 min.). Then add the garlic, salt, some pepper, and the chopped porcini and sauté for an additional couple of minutes on low heat.
Add the rice and continue to sauté while stirring for an additional couple of minutes. Begin adding stock one cup at a time stirring the pot regularly. Add the wine after the first stock and then add additional stock as the last is absorbed. Stirring at this point makes for a creamier risotto. Cook until the rice is still a bit firm (al dente), adding additional stock to make a more liquid dish, if desired.
Stir in ½ of the cheese along with the butter.
For an added grand finish, add some small, firm, fresh porcini (or baby bellos or crimini mushrooms), sautéed in butter, and stirred in at the end or served on top of each portion.
The exact amount of liquid needed to cook the rice is inexact, and you may either have stock remaining or need extra stock to complete the cooking.
Serve with remaining cheese to top the portions and extra ground pepper and salt as needed.
6
THE AGARICUS BROTHERS
Life is too short to stuff a mushroom.
SHIRLEY CONRAN, SUPERWOMAN
Agaricus is the genus of the western world’s most economically important and widely used cultivated edible mushrooms. It is home to the nearly ubiquitous button mushroom, portabella, crimini, and other thoroughly domesticated mushrooms, along with some lovely wild cousins living in a suburban or rural neighborhood near you. The name is Latin, meaning gilled mushroom, and in the very early days of mushroom taxonomy, all gilled mushrooms were placed in the genus Agaricus. The system quickly became unwieldy and, as the recognition of related groups became more sophisticated, other genera and families were designated to accommodate the observed complexity.
TAXONOMY
It is estimated that there are more than 200 species in the genus Agaricus in North America, although there has not been a close taxonomic study of the genus in some time. Most good mushroom field guides include, at most, six to ten common species. Clearly there are many other, less common species that do not make the guides.1 In the Northeast, the most common edible species are A. campestris, (the meadow mushroom or pink bottom), A. arvensis (the horse mushroom), followed closely by A. silvicola (woodland agaricus). Occasionally other species are collected and at least two have caused gastrointestinal distress. Along the West Coast, there are additional species and several more responsible for sickenings.
The most familiar agaricus by far is Agaricus bisporus, the domesticated white button mushroom. The brown crimini and portabella mushrooms are cultivars of this same species. The A. bisporus group is responsible for close to $1 billion in yearly sales in the United States and is heavily cultivated in Europe, China, and many other regions of the world. The species accounts for 40 percent of the cultivated mushrooms currently sold worldwide and was the first mushroom cultivated in Europe. Farmers in France first began to notice the growth of A. bisporus in beds of melons cultivated in greenhouses around Paris in the mid-1600s. The melons were fertilized with aged manure from area farms and stables, which was the perfect medium for Agaricus to grow and flourish. The farmers began to encourage the mushrooms’ growth and developed a local market supplying mushrooms to area eateries. For many years this technique for mushroom cultivation remained a closely guarded secret. By 1800, French mushroom farmers had learned that light in the greenhouses or field beds was not needed for mushrooms to grow and production began moving into the caves and catacombs surrounding the cities where there was more control over temperature and humidity. By that time, farmers in England, the Netherlands, and other countries in Europe also had begun to cultivate the popular mushroom and by late 1860s cultivation of mushrooms began around Philadelphia, Pennsylvania, as well. During the early years, piles of manure were inoculated using soil collected from areas where the fungus was fruiting. The technique was crude, and other mushroom species competing for the same food source would frequently appear in the beds. As people developed a better understanding of how mushrooms grow, an industry arose to produce spawn (mushroom mycelium) to provide as starter stock to growers. Initially, American mushroom farmers imported spawn from England until a spawn-generating industry sprouted in the United States in the early 1900s. In the 1920s, an American mushroom farmer, Edward Jacobs, developed a technique for making a pure spawn of Agaricus and thereby greatly reduced the number of competitive species in the mushroom beds. Around the same time period, an observant Pennsylvania mushroom farmer noted an almost pure white form of the mushroom in his beds and from this chance mutation sprung the development of the pale “supermarket mushroom” that now dominates the commercial Agaricus industry. From the relatively stable temperature and humidity conditions of caves and old mines, mushroom production has now moved into long, low production houses with exacting control over moisture, temperature, pests, and air circulation. Cultivation of Agaricus occurs in a number of places throughout the United States, most notably in Pennsylvania, the largest producer, and California the second.2
DESCRIPTION
Agaricus species share a few features that make them fairly easy to distinguish.
All have gills, which start out light cream, become pink to reddish as the cap opens (see #11 in the color insert) to reveal them, and then mature into a dark chocolate brown. The spore color is also dark chocolate brown. The gills are free of the stalk, which has a noticeable ring (annulus) that can be single, double, or pendulous. At times the annulus is almost absent in mature fruiting bodies as weather and time wear it off the stalk. In dry weather or on mushrooms that fruit in open sunlight, the annulus can remain fixed to the margin of the cap and get pulled off in tatters that remain attached to the cap edge. There is one other notable characteristic of Agaricus; if you hold the cap firmly and give the stalk a gentle twist it will separate cleanly from the cap without any gill fragments. This underappreciated feature has spawned the creation and proliferation of the stuffed mushroom cap, a mainstay of the cocktail party.
COMMON EDIBLE NORTHEASTERN AGARICUS SPECIES
The meadow mushroom, Agaricus campestris, a short-stemmed stocky mushroom that has a whitish cap and stem and grows in open grassy areas. The cap is commonly 2–4 inches in diameter, imperfectly rounded, and becoming almost flat at maturity and smooth to somewhat fibrous or even scaly. Lest you confuse this with an amanita, be absolutely certain that the free gills are not white but pink in the button stage and quickly age to pinkish brown and then dark bittersweet chocolate brown. There is a ring on the stem that may disappear as the mushroom ages. The spore print color is blackish-brown.
The horse mushroom, A. arvensis
, is the big brother to the more diminutive A. campestris. The horse mushroom is usually 4–8 inches in diameter, although 8–10-inch caps are not uncommon. The faint scent of almonds often accompanies this mushroom. The ring on the stem is more distinct and membranous than those in the meadow mushroom. Where the gills of the meadow mushrooms are pink, even in the button stage horse mushroom gills are cream-gray but then undergo the same color transformation as A. campestris, and become very dark brown. As with the meadow mushroom, the horse mushroom favors open grassy areas.
Agaricus bisporus: the button mushroom, supermarket mushroom
Agaricus campestris: meadow mushroom, pink bottom, button mushroom
Agaricus arvensis: horse mushroom
Agaricus abruptibulbus and Agaricus silvicola: woodland agaricus
A. silvicola and A. abruptibulbus are two woodland species that are very similar to each other in appearance and habitat. Both are taller and more stately looking than the horse and meadow mushrooms and have fleshy, pendulous rings on long slender stalks. Each species has a swollen stem base, though it is more pronounced in A. abruptibulbus. In addition, the scent of sweet almond is often present in the flesh. Both are recognized as good edibles.3
CAVEATS
The risk of collecting toxic Amanita mushrooms mistaken for edible Agaricus is low in the Northeast and Midwest if you follow a couple of simple steps. Make sure the gills are developing the distinctive transition to pink and brown and avoid any buttons with white gills, seen when sliced open. Also make certain the stem base shows no signs of the distinctive Amanita swollen base and volva. Look for whitish mushrooms growing in open areas with free gills that transition from almost cream through pink to dark bittersweet chocolate brown and with a ring on the stem. A blackish-brown spore print is important.
In the northeast United States, we have few species of Agaricus that cause toxic reactions, but there are a couple of species that can cause distress for some people. A. placomyces and A. meleagris both tend to have a darker speckled cap with an umbo or darker flattened center. A. meleagris bruises yellowish and has a strong odor of phenol (a chemical smell like creosote) or ink. A. placomyces stains bright yellow on the base of the stem. Agaricus xanthodermus is another toxic species that bruises bright yellow, especially at the base of the stem, and has a chemical smell. Avoid eating any Agaricus mushrooms that stain yellow or have a strong chemical odor! On the West Coast, there are several common agarics that trigger gastrointestinal distress and tend to resemble edible species. According to David Arora, this has made Agaricus the most common mushroom genus causing gastrointestinal reactions in California and Oregon.4
One additional caveat regarding the genus Agaricus: Many mushroom species, including members of Agaricus, are able to concentrate heavy metals and take up some pesticides. The horse mushroom is especially adept at metal accumulation. For this reason, avoid collecting mushrooms from along heavily traveled highways or in areas where you know or suspect there has been heavy chemical treatment or possible chemical contamination. Many golf courses use extensive chemical management to maintain lush, weed-free grass. For this reason, I generally avoid collecting and eating mushrooms from golf course fairways. Beware the well-manicured lawn!
ECOLOGY, HABITAT, AND OCCURRENCE
Agaricus campestris and A. arvensis both favor grassy areas in lawns, ball fields, roadsides, and graveyards. I have noticed that they are more common in areas where the grass is not perfect and fruit even better in grassy areas that support a population of weed species. So seek them out in areas of stony soil, rough lawn, and the edges of roadside drainage ditches. They typically fruit gregariously in scattered groups. Agarics will, at times, develop large fairy rings of several dozen mushrooms, and you can often tell where one will pop up before the mushrooms appear by the deeper green color and lush growth of grass in a circle or arc. Be aware that other mushrooms can form fairy rings and stimulate grass growth in the same way, including edibles such as the fairy ring mushroom, Marasmius oreades, and toxic species such as the sweating mushroom, Clitocybe dealbata.
Agaricus mushrooms have evolved as saprobes and most are what is known as secondary saprobes. They grow by continuing the breakdown of dead vegetative material that has already been partially decomposed by a primary saprobe. That is why they are commonly found in fields and farmyards and around composts and waste piles. The commercial mushroom industry follows a very carefully controlled process of composting horse manure and other plant matter to produce bedding substrate on which to grow button mushrooms.
One trend I have noted over the years is that in a summer when we have abundant rain evenly delivered through the season, there is little fruiting of A. campestris and A. arvensis is also not as exuberant. I believe that this is due to the grass duff being consumed by other “rotters” such as slime molds, bacteria, and other fungi able to outcompete the Agaricus during wet periods. If my theory is correct, a few weeks of dry weather should yield a strong flush of meadow mushrooms when we have one of those tropical deluges come September or October. The meadow mushroom fruits strongly during wet periods from August through September and can continue into October. The horse mushroom starts a few weeks later in a typical year but can continue to fruit through October and even into November in mild regions. Occasionally these mushrooms can be found in early summer during unusually wet weather.
EDIBILITY, PREPARATION, AND PRESERVATION
Most experienced mushroomers rate the meadow and horse mushrooms as good to choice edibles. I find their flavor to be distinctive and full, with the taste that most people associate with mushrooms. Young buttons have a mild flavor that increases in strength and depth as the mushroom matures. For this reason it is good to consider the dish you are cooking and determine whether you desire a strong mushroom presence or a lighter touch and use mushrooms matured to suit your needs. More likely you will collect the mushrooms and choose the dish based on the age of your mushroom bounty that day. You will find no better mushrooms for a hearty, creamed mushroom soup or mushroom gravy than the meadow and horse mushrooms! As with most of our edibles, the best way to start is to sauté cleaned, sliced mushrooms in butter or olive oil before proceeding with whatever recipe you choose.
In my copy of The Mushroom Handbook—that first guidebook I bought as a young man—Louis Krieger states the wisdom of his day regarding the poor nutritive value of mushrooms. “It is mainly as condiments that they are valuable. Beef, bread and beans are very nourishing, but who wants to eat these at all times?”5 Contrary to our old beliefs, mushrooms are packed with great nutritional benefits. The Agaricus species contain 35 to 40 percent dry weight of protein including a relatively good amino acid complement. They are also a good source of vitamin D and several B vitamins as well as of potassium, phosphorus, and selenium.
In a good year it is easy to find and collect more Agaricus than you can use in a few meals and therefore preservation strategies need to be considered. Mushrooms sliced and sautéed in butter or olive oil can be frozen easily for later use. More mature caps with strong flavor can be dried and are great for use as a seasoning when powdered in a food processor. Store the powder in an airtight jar, and use it to flavor soups, sauces, and stews. One way that I preserve large quantities of agarics is to make a sauce duxelles.
WILD MUSHROOM DUXELLES SAUCE
2–4 tablespoons butter, olive oil, or a mix
2 pounds mushrooms, coarsely chopped
Salt and pepper to taste
3–4 tablespoons minced shallots (optional)
2–4 tablespoons white wine (optional)
A sprig or two of fresh thyme, tarragon, or dill (optional)
Mushroom duxelles is a preparation dating back to seventeenth century France. La Varenne, chef to the Marquis d’Uxelles around 1650, reportedly invented the mushroom paste. I like it with the distinctively strong flavor of mature Agaricus mushrooms, but it can be made with almost any mushrooms, though I would suggest not mixing species into one batch, as
it muddies the flavors. Duxelles is made by coarsely chopping the mushrooms (which can be done in a food processor or by hand) and cooking them down in an open shallow sauté pan to concentrate the mushroom essence. When most of the liquid is evaporated and the mushroom paste is thick, it is ready for immediate use or can be refrigerated or frozen for later use. I spoon ½-cup portions of duxelles into muffin tins and freeze them. Later I pop the hockey puck duxelles out and into zip-lock bags for storage in the freezer. Duxelles also can be stored in the refrigerator for up to two weeks. I use it as flavoring in a vast array of recipes, as a garnish, or simply spooned on crusty French bread. Yumm!
CREAMY MUSHROOM SOUP
3 tablespoons butter
1 medium–large white/yellow onion, finely chopped
2 garlic cloves, peeled and crushed
1 tablespoon unbleached flour
5 cups vegetable/chicken/mushroom stock heated to a simmer
1–2 pounds meadow and/or horse mushrooms chopped in large chunks
½ cup white wine
¾ cup cream
Sea salt and freshly cracked black pepper
Chopped fresh parsley (for garnish)
