A hand written notice in the West London restaurant window advertised white truffle fresh from Italy. The lunch menu offered only two choices: truffle on pasta or truffle on risotto—both at substantial premiums to normal prices. I ordered the risotto, which arrived as a steaming bowl of very plain rice—no frills, no peas or bits of vegetable or meat. The head waiter hovered with a little plastic box and a stainless steel slicer. As he opened the lid, an earthy, musty, musky, garlic and cheesy smell drifted over the table. He shaved half a dozen extremely thin slivers of the brownish-white ball-shaped thing in the box onto the rice. It didn’t seem like much for the amount of money involved. But as the truffle slices were warmed by the steaming rice, the smell intensified and developed new notes—forest floor, damp leaves, sweaty socks and something indefinably sexy and alluring. After lunch—in fact, through the rest of the day and well into the evening—I experienced what aficionados call the “truffle burps”—little eructations of truffle flavour—the classic sign of a good truffle meal. Like the wild pigs of the French forest, the burrowing mammals of northern Italy or Australia’s long-nosed potoroo, I was hooked on truffles. Nearly twenty years later, I still am.
Truffles are smelly bags of spores, designed to be eaten. They are the fruiting bodies of fungi that grow in association with trees. They’re the underground equivalent of the mushrooms that pop up round trees in autumn, and the heady brew of chemicals that gives them their powerful aroma and beguiling flavour is their way of getting their spores distributed. Ordinary mushrooms push their caps above ground and shed spores onto the wind, but truffles rely on persuading animals to carry the spores around in their stomachs, to be dispersed around the forest in dung. As the fruit bodies grow and ripen, they synthesise aroma chemicals which spread out into the soil and eventually reach the air. Long before a passing human nose would detect anything, animals and insects will track them down and start feasting. These are not subtle scents. They have considerable complexity and delicacy, but underlying that is power. If you put your nose into the hole where a perfectly ripe truffle has just been unearthed, the smell can be overpowering—almost sickening. If you leave a ripe truffle in the fridge overnight, its smell will permeate everything in there. To a pig, or to the sensitive nose of a trained dog, finding truffles is not much of a challenge.
That smell is the key to the high value humans put on truffles. It is attractive in itself—we’re mammals, after all, and truffles have evolved to be attractive to our sort—but truffles also have a transformative effect on food. The Périgord or French black truffle, Tuber melanosporum, not only lends its own flavour to the dishes in which it appears, but also seems to intensify the flavours of the ingredients it accompanies. A steak with a truffle sauce is more meaty, a simple egg becomes a luxury item. That’s why the black truffle is one of the key ingredients in the finest expressions of French cuisine, as highly valued as fine wines or foie gras, and that’s why fresh truffles can command high prices. New Zealand grown Périgord black truffle sells for around $3500 per kilo during our winter season—June to August—and we can’t grow enough to meet domestic demand, let alone begin exporting to the world.
Hiding underground might seem a strange choice of reproductive strategy, but in evolutionary terms it has been very successful. Truffle-like species are found in forests on every continent (except Antarctica, not noted for its forest cover). Truffles can be as much as 90 per cent of the diet of Australia’s long-nosed potoroo, depending on the season, and over the Bass Strait the Tasmanian bettong has been recorded as eating 49 different species of hypogeal—underground fruiting—fungi. In the Douglas fir forests of Oregon and the Pacific northwest of the USA, deer, squirrels, mice and many other animals feed on the indigenous truffle species. In my North Canterbury truffle plantation—called a truffière—mice with expensive tastes are the bane of my life.
Truffles are the link in a three-way symbiosis between plant, fungus and animals. The relationship between the host tree and the truffle fungus is the foundation of this food chain, and it’s by no means unusual. About 90 per cent of all plant species have to grow in association with fungi. The “body” of fungi consists of extremely fine tubes called hyphae. These extend out from the plant roots into all the fine spaces in the soil, vastly improving the plant’s ability to access nutrients. One gram of soil can contain up to 20 metres of hyphae. On a young pine tree about 80 per cent of the surface area of the total root system will belong to its fungal partners, even though the fungi might only account for 20 per cent of its mass. This plant-fungus relationship is called a mycorrhiza (from the Latin for fungus-root). The fungus supplies the tree with nutrients from the soil, and in return the tree supplies sugars manufactured in its leaves. Without fungal companions, a young tree will struggle to grow. The fungus needs the tree, and the tree needs fungus. In every forest on the planet, the soil is permeated by mycorrhizal fungi, forming complex communities of fungi and plant roots, linking trees through the soil. A single tree might form relationships with many different fungi, and a single fungus might link up with several trees—even move nutrients from one tree to another. The straggly pine shelter-belts so common in New Zealand host their own fungal community, even if the only visible sign is the occasional fly agaric—Amanita muscaria, the red capped and white spotted mushroom made famous in Alice In Wonderland—that pops up in autumn after rain.
Truffles are harvested for human consumption around the world. There is a thriving global trade for the two big stars—the Périgord black truffle, which is harvested in the wild and in plantations, and the Italian white truffle, Tuber magnatum, which has so far eluded all attempts at cultivation. Naturally, the French regard their truffle as the world’s finest, whereas the Italians can point to the high prices magnatum fetches—and the world record prices it sets at auctions every year. Last year, Hong Kong property developer Gordon Wu paid 125,000 for a 1.5 kg specimen of magnatum at a charity auction, and then confessed that he didn’t really like truffle—he had only bought it to impress guests at a party.
Although the Italian white truffle is the one that captures the headlines, it’s the Périgord black that has shaped the world trade in truffles. Its natural habitat is the oak forests that cover (or used to cover) large parts of central and southern France, Spain and central Italy. It likes highly alkaline limestone soils, often seeming to grow in shattered rock, and it prefers the holm or evergreen oak, Quercus ilex as its host, though it will also grow well with other oaks and hazels. It’s adapted to the hot dry summers of central France and Spain, but needs a certain amount of autumn moisture to fruit. It ripens from December to March. Périgord black truffles were collected in the wild in France from at least the Middle Ages onwards, but it was a breakthrough in truffle cultivation in the early 19th century that transformed a peasant pastime into big business. In 1811 Joseph Talon, from the hamlet of Croagne in the Luberon, a valley in the north of Provence, planted some acorns in the stony soil of a known truffle producing area. Six or seven years later, truffles started to appear round the young trees, so Talon repeated the experiment, buying up more land, planting more oaks and becoming more wealthy as he sold his increasing crops. He tried to keep his technique a secret, but the source of his new-found riches was soon discovered, and this crude form of truffle cultivation quickly spread from Provence into the other great truffle region, the Périgord. Planting there started in the 1840s, but really took off when phylloxera devastated the region’s vineyards in the 1870s. Local government encouraged farmers to rip out their vines and plant the new-fangled truffle oaks, and over the next 20 years truffle production boomed. By the beginning of the 20th century France was producing somewhere between one and two thousand tonnes of truffles a year, and the peasants of the Périgord were becoming rich. Truffles were taken to local markets by the sackload, in carts piled high. Big new houses were built around the market villages that were turning into small towns. Railways took the fresh truffles to the big cities, where they became a highly fashionable luxury. Surplus truffles were bottled and canned and shipped round the world.
The good times lasted until WWI, but soon after production went into a steep decline. The new truffières were ageing and becoming less productive, and the wild harvest was reducing as traditional forest management practices—firewood gathering, coppicing and grazing of animals—became less common. By the 1960s, the annual harvest was well under 100 tonnes, and today a 30 tonne year would be considered good. Faced with the apparently inexorable decline, France’s truffle dealers looked across the Pyrenees to Spain where similar oaks grew in the same high limestone soils, but there was no tradition of truffle harvesting. Spain turned out to have plenty of truffles, and in the last 20 years there has been a considerable expansion of both harvesting in the wild, and planting of new truffières.
The story of the Italian white truffle is very different. It is only found in the wild in northern and central Italy and the Istrian peninsula of Croatia, and it has never been successfully cultivated. Many have tried, and scientists and growers continue to experiment with producing Tuber magnatum infected trees, but it is proving a tough challenge. The truffle likes different conditions from the Périgord black, preferring deep, free-draining alkaline soils in moist valley bottoms, growing with poplars, willows and limes. Its popularity in Italian cuisine was boosted by the great Italian diaspora that spread into the USA and later, into Australia. The white truffle became a symbol of the culinary connection with the homeland, but it was clever marketing—always one of Italy’s strengths—that established it as the most prestigious of truffles outside the francophone world.
Truffles are not usually large. They range from the size of a walnut up to a cricket ball, but occasionally something clicks and a really big truffle develops. For the Perigord black, around one kiloih bfl. would be the upper limit (one that size was harvested in Western Australia a couple of years ago), but the Italian white can do better. In 1952, a truffle hunter in San Miniato in Tuscany found a magnatum that weighed 2.52 kg. He sent it to a man called Giacomo Morra, in the then obscure Piedmont town of Alba, about an hour’s drive from Turin. Morra owned the town’s Savoy Hotel. In the 1930s he had started calling magnatum the “white truffle of Alba”, and begun promoting the town’s truffle market as a tourist destination. His stroke of genius was to give some of the truly enormous truffles that turn up in most seasons to famous stars. In 1949, he gave a fine example to Hollywood star Rita Hey-worth. 1952’s record breaker—still the largest ever found—was sent to US President Harry Truman. Others who received heavily-promoted souvenirs from Alba included Marilyn Monroe, General de Gaulle and at least one pope. Alba became known as the home of the Italian white truffle, and it is now a major tourist destination. The power of Morra’s marketing still echoes around the world today. You can find people—mainly outside Italy—who will insist that the finest truffles come from Alba, though the reality is that most of the truffles that pass through the Alba market come from elsewhere. Istrian truffle hunters take their white truffles into Italy to sell, because that way they get a better price.
The Italian white truffle harvest seldom exceeds 50 tonnes per year, and is often much less. Supported by huge international demand, prices are always high—sometimes stratospheric. When I visited the Alba market seven years ago, prices were nudging NZ$5000 per kilo. I didn’t buy any. With such high prices to be had, competition between tartufaio—truffle hunters—can be intense. The keys to success are a comprehensive knowledge of the best sites, and a well-trained truffle dog. Without the dog, the tartufaio is hunting blind. Good dogs therefore command a premium price, whether trained at the truffle dog university in Alba, or by the hunter. They also become prime targets. Unscrupulous truffle hunters have been known to leave bits of poisoned meat lying around at prime sites in the hope of killing a rival’s dog. Champion hounds have been stolen.
The French are not immune to this problem. A recent run of hot, dry summers has meant poor crops of the Périgord black in truffières and low harvests in the wild, pushing prices up. Poaching has become a serious problem. One Périgord grower of my acquaintance spends many winter nights hiding out in his truffière, waiting for poachers. If he sees their torches, he fires a marine flare to scare them off—and has been known to fire his shotgun at the thieves. In an incident in Provence, a poacher peppered with shot by an angry truffière owner turned out to be the president of the neighbouring area’s truffle association. In Italy, one truffle grower is reported to have laid land mines around his truffière to deter poachers.
If scarcity and high prices lead naturally to poaching, they also provide a strong motive for fraud. In the early ’90s China began exporting black truffles to Europe. Chinese truffles are harvested in Yunnan province in the foothills of the Himalaya, and some species look remarkably similar to the Périgord black truffle—so similar that they can be hard to distinguish without DNA testing. And they can be bought for $US50/kg, when good quality Périgord truffles fetch $US2500/kg. The only drawback is that the Chinese harvest their truffles with rakes, not dogs, so the quality of truffle is variable. Ripe ones get mixed up with unripe ones, and the truffles that arrive in Europe are a pale shadow of the true Périgord truffle. The profit potential inspired some truffle dealers to take advantage of one of the strengths of Tuber melanosporum—its ability to lend its flavour to other things. If you put a few Chinese truffles in a container with a good Périgord truffle, they will absorb some of the aroma. After a day or so, it will be difficult for even an expert to tell them apart. Unfortunately, when the truffle is used in cooking it reverts to type—a pale shadow of the real thing. The Chinese truffle export business boomed. By the middle of the 1990s, Chinese truffle imports to Europe are estimated to have been greater than the total volume of Tuber melanosporum harvested. Truffle buyers around the world were being ripped off. The ensuing scandal—here was a Chinese interloper devaluing the black diamond of French cuisine—led to new labelling standards, and sparked research on how to identify the truffles reliably. DNA tests have been developed, and the Chinese truffle “problem” is now under control. China continues to export truffles by the tonne, but they are now sold around the world under their own name—Tuber indicum.
High prices have also driven scientific innovation. In the 1970s, faced with the apparently inexorable decline in the truffle harvest, French scientists began to experiment with methods of improving on Joseph Talon’s technique. When a tree seed germinates in a forest, its roots move down into the soil and strike up relationships with whatever suitable mycorrhizal fungi may be present. As the tree gets larger and its roots grow, it will encounter different fungi. If one of them is a Tuber species, then the tree may become a truffle producer when it grows up. The French mycologists decided to see if they could control this process, to produce seedling trees infected with melanosporum and then grow them on until they were big enough to produce truffles. They germinated seeds of suitable tree species—oaks and hazels, mainly—and grew them in a sterile medium until they were large enough to handle. The trees were then inoculated with truffle spores, repotted in a suitable sterile potting mix and left to grow in greenhouses designed to keep out the spores of competing fungi. If everything went well the truffle spores would germinate, establish a mycorrhizal relationship with the roots, and then become established in the soil of a new truffière when the young trees were planted. The technique worked, and in the late ’70s the first truffles were harvested from the artificially-infected trees. Variations and refinements of this approach are now used around the world with several species of truffle and many different host trees, and it has led to a revolution in the global truffle business—including the introduction of European truffles to New Zealand as a new high-value crop.
New Zealand mycologist Dr Ian Hall heard about the French success at a conference in the USA in 1979. His initial thoughts of introducing truffles to New Zealand fell foul of government funding cuts in the early 1980s, but in 1985 he was able to cobble together enough money to begin work. He couldn’t simply import truffle-infected trees from Europe: quarantine restrictions were far too tight. He had to repeat the French work and develop his own method of infecting trees. Working with his team at Crop & Food Research at Mosgiel, he eventually succeeded in infecting seedlings of English oak, Quercus robur, and hazel, Corylus avellana. The first couple of trial plantings were made in North Otago in 1988, and a further nine truffières at a spread of sites around the country from the Bay of Plenty to Canterbury were established the following year. On July 29th, 1993, at a truffière established by Hall’s brother Alan in Gisborne, the first Périgord black truffles to be grown in the Southern hemisphere were harvested. It was Ian Hall’s birthday. A few days later, a neighbour’s pigs, excited by the truffle smells wafting over the fence, broke into the truffière and scoffed the remaining crop.
New Zealand’s entry to the truffle world might have taken Europe by surprise, but there was sound scientific and commercial logic behind Ian Hall’s work. The country spans a wide range of climates, many of them similar to those of the truffle producing regions of France, Spain and Italy. There is no shortage of limestone country, though none of it much resembles the high limestone plateau of central France. In fact, one of Hall’s key innovations was the idea of adding lime to soils to create the highly alkaline (pH 7.8 or higher) conditions that the Périgord black truffle requires. Of those first nine sites planted in 1989, all bar one were on extensively modified soils—ranging from deep volcanic soil in the Bay of Plenty, through river loams in Gisborne to an old sand dune on the Kapiti coast. The French had concentrated on planting their trees in existing truffle regions—places where they knew the truffle already grew. The fledgling New Zealand industry didn’t have that luxury. But soil modification worked, and all of those sites have now produced truffles—in fact, the truffière in the volcanic soil in the Bay of Plenty is remarkably productive.
The other key factor underpinning the growth of the business in New Zealand is the fact that Périgord black truffles are only at their best when fresh. They can be canned or bottled, and if this is done carefully the results can be quite good—but the end result is not as intense or aromatic as the fresh product. Freezing changes the flavour and reduces the aroma. The European melanosporum season runs from December to March. The New Zealand equivalent is June to August. In other words, we have fresh truffles when the Northern hemisphere has to make do with the preserved. The potential export market is large—covering the world’s top restaurants and hotels. It’s a premium product that should sell for premium prices.
Since 1997, when Alan Hall produced his first commercial crop, New Zealand has been producing good quantities of truffles every year. There are currently nine producing sites, from the Bay Of Plenty and Gisborne down to Ashburton, with Canterbury boasting four productive truffières, three of them in the warm limestone country of north Canterbury near Waipara. There are over 100 truffières around the country, from small sites such as my own, which has 200 trees, to large commercial plantations with many thousands. So far, the annual crop has been sold on the domestic market to upmarket lodges, hotels and restaurants, with prices stable at around $3500/kg. Trial exports have been made to several countries. There are three nurseries supplying truffle-infected trees, and over the next few years the industry expects the area of truffières to increase substantially. There’s every chance that over the next 10 years, truffles can become a multi-million dollar export business. The truffle growers’ organisation, the NZ Truffle Association, is already working on quality control systems and collaborative marketing initiatives to provide the infrastructure for a rapid expansion of crop volumes.
Establishing a truffière is not a complicated business. Find a good site with the right climate, and away from trees that might harbour competing fungi. Make sure the soil has the right pH, put in irrigation, and then plant the infected seedlings. Keep weeds away from the young trees, and every spring aerate the soil around the trees to provide the right conditions for truffles to form. After a few years, you should see clear signs of the truffle working with the tree—a zone of reduced weed growth around the trunk called a brulée. This is a part of the co-operation between fungus and host. The truffle actively suppresses weeds around the tree, helping to reduce competition for water and nutrients. When the brulées are well-established (they are usually most visible towards the end of summer), truffle production should not be too far off. When I planted my trees in 1997, the standard advice was that it might take five to ten years to get your first truffles. It took us nine years to get our first, and the longest wait we know about was 14 years. In recent years, it appears that a combination of good management and site preparation can bring that figure down towards the bottom end of the range. One Australian truffière recently reported its first production after only four years. The harvest potential is difficult to estimate—we don’t have enough information yet to predict how yields will vary with site location and tree age—but there are encouraging signs that financial returns could be very good. Yields of 20–40kg per hectare look achievable in well-managed plantations, and with market prices at $3500/kg, you don’t need too many kilograms per hectare before the returns become interesting.
When the trees are approaching production, you will need to acquire a truffle dog—or more than one if your truffière is large. At the world’s largest truffière, the Arotz plantation near Soria in Spain, they have dozens of trained dogs to help them cover the 600 ha, 400,000 tree plantation. Without a dog, you are relying on luck to find truffles—either that or you will have to spend most of the winter crawling around your trees on your hands and knees sniffing the soil. In France, the use of a young pig is certainly traditional, but even there dogs are now much more popular. Pigs are difficult to get into the back of a car, and like eating truffles too much. Being towed around a truffière by a large sow intent on supper is not an attractive proposition. Dogs are friendlier and willing to work for small treats such as bits of sausage, cheese or bread. It’s not too difficult to train your own dog—my beagle, the amazingly charming Peg, was home-schooled and has won the national truffle dog championship twice—but you can have your dog trained by professionals, or buy a ready-trained animal.
Australia hasn’t been slow in following New Zealand’s lead. In 1993, around the time that Alan Hall was harvesting his first truffles, the first truffières were established in Tasmania. In 1999, the first Aussie truffle was harvested by Tim Terry at his Askrigg property near Launceston. Tasmania now has over 180 ha of truffières, and there are substantial plantings in Western Australia, Victoria and New South Wales. Truffles have been produced in all those states, and production volumes are beginning to become substantial. Exporting has begun to both Europe and Asia. New Zealand’s growers are watching developments in Australia with interest, but are not greatly concerned about competition. The potential market in the Northern hemisphere is very large, and it will be decades before the southern hemisphere is producing enough truffle to satisfy the potential demand, even if experimental plantations in Chile and South Africa bear fruit.
New Zealand led the development of Southern hemisphere production of Tuber melanosporum, and it is continuing to innovate in the truffle market. Crop & Food Research have been working on bringing other truffle species to the world’s tables, particularly the Burgundy truffle, Tuber uncinatum, and the bianchetto truffle, Tuber borchi. The Burgundy truffle is a close relative of the Périgord black, but has a milder taste and less powerful aroma. It fruits in the autumn, and while it doesn’t command the same premium price as the Périgord black, it extends the season when growers have truffles to sell. The same is true of the bianchetto. It fruits in late winter, and is regarded as the white truffle that comes closest to the flavour of the famous Italian white truffle. Crop & Food produced their first bianchetto at a trial plantation in Lincoln in 2006, and there are already commercial plantations established in several parts of the country. Both truffles have wider soil and climatic tolerances than the Périgord black, and so can be grown in parts of New Zealand not suitable for melanosporum. Ultimately, when Burgundy and bianchetto truffles are in commercial production, the New Zealand truffle season will stretch from autumn—perhaps April—through to August and September.
In Europe, low truffle production continues to cause concern. The EU is pouring millions of dollars into truffle research in an attempt to boost production, but growers are becoming increasingly concerned that climate change is beginning to have an impact. A run of hot, dry summers in France, Spain and Italy has reduced the harvest—and boosted poaching. Meanwhile, across the Atlantic new truffières in the USA are beginning to produce respectable crops of the Périgord black truffle. There have been experimental plantings in the USA since the 1980s, but in recent years decent crops have been produced in North Carolina, where truffières have been promoted as a replacement for tobacco, and in Tennessee. On the west coast, there are Périgord black truffle plantations in Oregon and California, and there are even experimental plantations in the south of British Columbia, where an enthusiastic group of Canadian truffle growers are determined to prove they can succeed despite being at the cool end of suitable climates.
Oregon and the Pacific north-west are also home to some interesting indigenous truffle species that can stand comparison with the best of the traditional European species. Growing in association with Douglas fir, several species of Oregon white truffle can be harvested from autumn until spring, and there are also Oregon black and brown truffles. The black truffle is particularly interesting. It’s not a member of the Tuber genus like most other commercially traded truffle species. Leucangium carthusiana has been described as “the world’s finest dessert truffle” as it has fruity, almost pineapple-like overtones to the background truffle aroma. It makes an outstanding ice-cream, and is regarded as a premium truffle by knowledgeable west coast chefs. The Oregon brown is a bit more of a challenge. Also highly esteemed by aficionados, it has a strong, almost blue cheese smell. All of these native fungi are potentially excellent culinary truffles, but they have one major drawback. Like Chinese truffles, they are mostly harvested by raking. This can deliver good yields, but patchy quality, because a harvester simply takes everything that’s there, however ripe it may. Another factor makes matters worse. Truffle harvesting is very competitive and so there is pressure to harvest a good location as early as possible, and to take as much as can be found. If you try to wait until most of the truffles are ripe, you run the risk of someone getting to the spot first. Efforts are being made to improve quality, and to encourage people to harvest with dogs, but it’s an uphill struggle. The Oregon experience also begs an interesting question about the harvest in China. If the Yunnanese harvesters were to use dogs so that Tuber indicum was only harvested when properly ripe, would the culinary reputation of that truffle rise?
It’s also possible that the native forests of New Zealand might be home to interesting and edible hypogeal fungi. Much of what we know about the truffles of the world was established by keen amateurs raking around the roots of trees, but without properly trained dogs to lead to you an interesting spot, it can be a very hit-and-miss process. As the New Zealand truffle business grows, and the number of trained truffle dogs increases, perhaps someone will wander into the West Coast bush and return with a sackload of interesting and valuable fungi.