by David Downie
Truffles in Black and White: Part Two, Truffle Hunting in Piedmont, Italy
The scent of truffles is what draws trained dogs and pigs to them. Wild or cultivated, truffles grow at random around host trees and must be hunted out and carefully removed using a small pick or trowel.
Eighth-generation truffle hunter and dog trainer Renato Agnello, a wiry dynamo in his late 60s, teaches truffle hunting at Alba’s Centro Nazionale Studi Tartufi (CNST) and leads simulated hunts. In Alba’s main square, Piazza Risorgimento, Agnello opened the back hatch of a muddy FIAT Panda and introduced me to his aging truffle hound, Diana. We drove at breakneck speed into vineyards bordering the Tanaro River south of town. The smell of Diana, dirt and truffles was dizzying.
In Italy, truffle hunters must be registered, trained and licensed. Piedmont’s 10,000 are reputed to be secretive. Agnello was expansive. “I’ve been at it 61 years,” he laughed. “With people and dogs it’s genetic.”
Italian law states that truffles on public or private land belong to their finder. To keep truffle hunters out, private property must be fenced and posted “no trespassing.” Trespassing is common, however, particularly in central Italy’s commercial black truffle plantations (there are no white truffle plantations).
The white truffle hunters of Piedmont work at night to avoid being spotted by rivals and thieves, though, as I was able to confirm, their flashlights often give them away. It was dusk by the time Agnello and I began tramping through frozen woodlands on the Tanaro. He suggested that to love, as he does, unearthing truffles in tangled underbrush in the cold and dark “you must be sick.”
A further explanation is that a sizable white nugget like the one Agnello had found that morning and now pulled from his shoulder bag to show me was worth over $500. White truffles are nicknamed “white gold.”
Widespread prosperity in Italy and an economic boom in Piedmont in particular have increased demand for white truffles. At the same time the economic and societal forces driving the boom are driving down truffle supply, primarily because of environmental damage. In recent decades throughout Italy, France and Spain truffle harvests have plummeted; melanosporum and magnatum pico finds are down tenfold since the 1950s, twentyfold compared to the early 1900s. Factors widely cited throughout Europe as contributing to the crisis include systematic over-harvesting, overpopulation of wild boars, soil compaction from tractors, acid rain, and careless truffle hunters who fail to refill the holes they dig, thereby exposing spores to lethal frost. Some problems are specific to regions, such as the industrial growth and increase in tract home building in Piedmont.
“There are more vineyards, villas and housing developments than before, fewer working farms, the woods are overgrown because no one maintains them, the willow trees have been cut because they’re no longer considered useful,” Agnello lamented. In Piedmont the basket willow may be the key to the problem.
Black truffles prefer oaks, but the white truffle’s favored host is the basket willow. For centuries, to bind their grapevines to rows of wooden stakes grapegrowers used willow switches. In recent decades cement posts and plastic ties have replaced wooden stakes and willow switches. “Farmers, grapegrowers and real estate developers cut down the willows and were surprised when we found fewer truffles. Now the region is replanting them and preserving woodlands,” he added.
Barking from excitement, Diana followed her nose amid oaks and willows, guided by Agnello. “This is a simulation,” he admonished. “Earlier I buried some bad black truffles here. I wouldn’t risk losing a white.”
Without difficulty Diana found each hidden truffle, circling, whining and digging until Agnello gently moved her aside. “It takes months to train a truffle dog. A good one like Diana is worth thousands of euros.”
Agnello rewarded Diana with a biscuit then refilled the holes she’d dug. “Dogs don’t naturally like truffles. Pigs do, and try to eat them, which is one reason we don’t use pigs in Piedmont any more. Pigs also grow huge, are hard to transport and restrain, so you really can’t keep them for more than a year.”
Agnello led me through an experimental black truffle plantation. “Some blacks but no whites,’ he remarked, “and the blacks often aren’t the right kind, not melanosporum, I’m not sure why.”
Dr. Paola Bonfante had a clearer idea of the challenges faced by truffle growers. A professor of mycology at the government-run Consiglio Nazionale delle Ricerche (CNR) and Università degli Studi in Turin, she and her research assistant Claude Murat study the genetic makeup, environment and life cycles of truffles to better safeguard, propagate and precisely identify prized species. Fraud is a growing problem throughout Europe, she explained.
“So far white truffles cannot be propagated, and many challenges with melanosporum cultivation remain,” the patient, mild-mannered Bonfante told me.
Truffles are symbiotic subterranean mushrooms that develop into edible “fruiting bodies” among the roots of a host tree through a complex (and not yet fully understood) process called “mycorrhization.” The tree provides carbohydrates, amino acids and hormonal substances; the truffle reciprocates with water and mineral salts.
“Truffles require specific soil types and pHs of 6.8-8.5, specific climates, altitudes, humidity, and host trees, and they’re sensitive to prolonged frost. Essentially, after the last and coldest glaciation 10,000 years ago melanosporum and other truffles followed the northward recolonization of white oaks and other hosts in Italy, France and northern Spain, but white truffles didn’t make it across the Alps.”
As a species white truffles are less “competitive,” meaning other, hardier species take over their habitat and drive them out. Many black truffle types proliferate by artificial means on spore-impregnated roots in tree plantations in Italy, France, the United States, Australia and New Zealand. Spain’s Arotz truffle plantation in the Pyrenees is the world’s largest, with over 150,000 trees. It produces several tons of black truffles a year. But, as is true of plantations everywhere, many of the truffles harvested, though black, are not melanosporum.
In recent decades inferior, morphologically similar, highly competitive truffles have infested plantations across southern Europe, raising doubts about the future of artificial mycorrhization and the aims of some truffle producers. Conspiracy theorists see a willful attempt to flood the market with easy-to-grow, bland truffles that unsophisticated consumers will eventually accept as substitutes for scarce, prized varieties that are difficult or impossible to grow. Among common, benign invader species are uncinatum (also known as “Burgundy truffle”) and aestivum (“summer truffle”), both edible. The truffle-grower’s bête noir, however, is brumale, a black winter truffle that ripens from November to early March like melanosporum, looks almost identical to it, is far less flavorful and aromatic, and up to 10,000 times more competitive and hardy.
In the third segment of Truffle in Black and White I travel to the truffle heartland of southwest France to find out more about melanosporum and brumale.
The photos in this series of articles of truffles were taken by Alison Harris. You can see the entire set as a slide show in Food Art: Behind the Scenes of the Noble Truffle, food photography by Alison Harris.