One of my most treasured memories is having mushroom soup at a restaurant in Reading, Pennsylvania called Joe's. After the soup was served, the waiter garnished it with a ribbon of crème frâiche in the shape of a mushroom. Hokey no doubt, but the soup, which was made with wild mushrooms expertly harvested from the local Reading hills, was aromatic, earthy, and intense.
The origin and evolution of Joe's restaurant is a fascinating slice of American culinary history, and the latest of Joe's progeny, grandson Jack—along with wife Heidi, now run the Joel Palmer House in Oregon. They carry on the great fungi food tradition that began in Reading by harvesting their own mushrooms. And the soup? It's on the menu for eight bucks. I don't know if they garnish anymore.
What's a mushroom?
Mushrooms are the "fruiting body" of certain types of fungi, and by fruiting body, I mean the nibbley bit: stem and cap. The biological purpose of the mushroom is to cast spores to the prevailing wind from gills located on the underside of the cap, or in the case of morels, from the many folds on its surface.
The 'mother fungus' that produces the mushroom lies beneath the surface in the form of a network of delicate filaments (called hyphae) that interlace with the soil, extracting nutrients. According to Harold McGee, there can be as many as 2000 meters of hyphae in a single cubic centimeter of soil beneath the visible mushroom...that's a lot of hyphae.
Unlike plants that photosynthesize their energy from the sun, mushrooms take it from the soil, from the decomposition of other plants, or from host plants. Shitake mushrooms are cultivated on oak logs, for example, which also accounts in part for their distinctive flavor.
Many mushrooms are poisonous, proving that the best defense is a deadly offense. By deterring animals from eating their spores, these fungi stand a better chance of scattering them to good effect. Paradoxically, the safely edible ones taste good to us because, in part, they naturally produce the flavor enhancer most often associated with chinese take out, MSG.
Truffles, A Whole Other Matter
Truffles are related to mushrooms in that they're both fungi, but rather than casting spores to the wind, truffles use their intoxicating aroma to call almost anything with a nose to the dinner table. When they're most ripe, these hard-shelled fungi release a powerful mix of chemicals that rodents, deer, pigs, and even dogs find (as we do) hard to resist. They eat the truffles, taking the spores on board, and deposit them elsewhere.
Interestingly enough, the siren smell of truffle includes androstenone, a male hormone found in armpit sweat (this also according to McGee), which might be why some of us find it so fascinating, while others literally turn up their noses.
Unlike other mushrooms that feed on decomposing plant matter, truffles grow within the root systems of oak and other varieties of trees. In exchange for minerals extracted and shared by the truffle, the tree returns the favor with energy produced from photosynthesis. It's symbiotic: everybody wins.
The most valuable truffles, the Italian white Alba and French Perigord black varieities, are definitely the bling of the well stocked larder. White Albas can go for as much as $1500 per pound, while Perigord blacks often fetch $900. For most of us, both the money and connections you need to get your hands on fresh truffles are well out of reach. And that, in a nutshell, is the trouble with truffles.