Everything you need to know about truffles

We learn the artisanal ropes behind truffles at three truffières located across Victoria and New South Wales.

Truffles, a form of edible fungi that are found on the roots of trees, are something you may only reserve for special occasions or fine dining as they’re much more expensive (approximately $3 per gram!) than their distant cousin from the fungi kingdom, mushrooms. Truffles may come at quite the cost, but once you learn about the artisanal farming ways at three different truffières (areas of land where truffles are found or cultivated), you may well be sold.

What are truffles?

“Truffles are the fruiting body of a fungus that is attached to the roots of trees,” reveals Col Roberts, who owns Lowes Mount Truffiere with his wife, Sue. “As a fruiting body, it consists of spores, which are like seeds. Some fungus-fruiting bodies appear above the ground where the wind disperses the spores. Truffles remain under the ground and rely on animals eating them to spread the spores. Animals can find them because they get aromatic when ripe,” he continues.

According to Stuart Dunbar, owner of Yarra Valley Truffles, “In spring they provide the tree with nutrients such as phosphorous, nitrogen and, later in summer, water. In return, the tree provides photosynthesised sugars during summer and autumn to the truffles for the formation of the truffle-fruiting body, which humans love to eat.”

Macenmist Black Truffles & Wines, which Barbara Hill owns with husband Richard, has three varieties of trees — hazelnut, English robor oak and French ilex oak — that make up their trio of truffle offerings. Hill further explains the symbiotic relationship between the trees and truffles: “The trees are inoculated with tuber melanophores, which is the botanical name for the French black truffle. The mycelia of truffles form a fungus-root relationship, where the tree root is colonised by the truffle fungus. The tree and the truffle have a symbiotic relationship, with minerals provided to the tree by the truffle and carbohydrates provided to the truffle by the tree,” explains Hill. “We know when there are truffles out under the trees because of the barren ground known as a brûlé (burnt patch), which indicates that fungi are active and present in the tree roots beneath the brûlé. The truffle also acts as a natural herbicide, preventing growth competition surrounding the tree,” she continues.

Truffle farming

As a forester, Col Roberts had experience in growing trees, so when he and Sue decided to retire in the Lowes Mount region, they researched the crop options for their property and discovered their soils and climate lent themselves to truffles and hazelnuts. “We thought they would be an interesting challenge for us,” Roberts explains, adding that their infected truffle trees are English oak, European evergreen oak and hazelnut. “To ensure the fungus flourishes when the trees are planted,” Roberts adds, “it is important to have the soil at the correct pH, the trees free from weed competition and pest animals and to provide sufficient water to keep the trees growing healthily. As the trees grow, they need to be pruned of lower branches and coppicing to provide access under the trees for harvesting. All of these requirements are part of annual management of the truffière. Now at 20 years, we have had to thin the truffière to reduce competition between trees for water, sunlight and nutrients.”

“In 2008, after two years of research, we decided to plant inoculated truffle trees,” explains Barbara Hill, adding that in just under three years, with the help of a truffle dog handler, they harvested their first truffle. “My love of dogs led me into buying and training two truffle dogs. Without these dogs I would not be able to harvest the ‘black gold’ known as the Perigord black truffle, nor would we be able to entertain the numerous guests that now visit our farm.”

“Prior to planting the inoculated trees, soil tests were undertaken and feral proof fencing and irrigation needed to be undertaken. Then, when the soil tests came back, we had to increase the soil acidity level (pH) by adding lime. This was then cultivated by multiple tilling methods. When all was ready, the trees were planted and surrounded by tree guards,” explains Hill. “Today, as the trees are now established, they only require annual pruning, irrigation and weeding. The area is also regularly mowed as this helps to control leaf litter that harbours slugs. The hazelnuts also require the nut biproduct to be collected annually,” she continues. According to Hill, the Snowy Mountains region can have a longer truffle season compared to other parts of Australia: “Our season starts at the first frosts of June and can continue until the ground temperatures start to warm up in September. Cold winters and hot summers promote the truffle growth.”

“Organic farming methods have significantly contributed to continual soil improvements, which have led to better-quality truffles and increased production to the point the production per hectare is among the best in the world,” Stuart Dunbar shares, adding that his organic farming approach is a year-round process. “Labour takes the place of herbicides and pesticides and we focus on soil improvement, structure and organic carbon.” In spring, Dunbar focuses on “soil aeration while the truffle is feeding the tree and tree roots are growing. Mowing and pruning continues into summer, when irrigation becomes important and the truffles begin to form. We’re protecting the truffles through autumn, removing any rotten truffles and preparing for the harvest that finally occurs mid-winter to early spring.”

Harvesting truffles

Truffières use trained dogs to sniff out truffles. When a dog starts scratching the ground, a truffle hunter marks the ground and uses their own nose to determine whether the truffle is ripe enough for harvest. The ground is then carefully loosened by hand to extract the truffle. You know a truffle is ready for harvest when it is firm as this an indicator of its ripeness — if it feels soft, it’s not ready. When cut, you can tell if a black truffle is ripe on the inside if it is dark with thin white veining. If the veining is wide then it’s not ripe. Place harvested truffles in water and use a nail brush to loosen the dirt on them — much like preparing potatoes to cook.

The taste of truffles

“A fully ripe truffle is difficult to describe,” explains Stuart Dunbar. “Aromas are best described as a deep, rich, velvety molasses and the flavour of a fully ripe truffle matches many simple foodstuffs — chicken, parmesan, eggs, cauliflower and pumpkin.”

“Eating truffle is as much about the aroma as it is about the taste,” reveals Col Roberts. “Lowes Mount Truffles grow the Perigord black truffle, which has a strong characteristic aroma ranging from sweet and earthy through to astringent and earthy,” he explains. “Aroma often depends on soil characteristics or ‘terroir’. Truffle eaten by itself has a mild taste and nutty texture, but the true value of truffle is what the combination of aroma and taste does to flavour food, particularly pasta, rice, potatoes, eggs and dairy products.”

According to Barbara Hill, the taste of truffles is quite subjective. “Some people describe a nutty taste and texture,” she says, adding that it can be an acquired taste. “Taste is 90 per cent aroma. During a smell test in a Western Australia university, Macenmist truffles were said to have the aroma of ripe bananas. But subsequent questions to Macenmist visitors have revealed that each person may have a differing opinion as to taste and smell,” she continues. “The glutamic acid in truffles means the taste is umami/savoury. The truffle aroma has great affinity for fats and is absorbed by them (oils, animal fats, egg yolks, cream). Like all foods, fresh is best!” she adds.

Are there any health benefits to eating truffles?

Studies have shown that truffles don’t provide any major health benefits, but they are 80 per cent water, easily digestible and high in fibre. “The main benefits from eating truffles will come when combining them with good-quality unprocessed foods to bring out a unique truffle flavour,” explains Col Roberts, adding that they are high in potassium.

Sustainable truffles

“Within the truffière we endeavour to maintain a pristine natural environment,” explains Barbara Hill. “Before entering the truffle, orchard footwear is disinfected to prevent the introduction of foreign contaminants that could be introduced to the truffière soils. When insects or pests need to be treated, we use non-chemical products, such as eco-friendly oils, thereby reducing the pollution from chemical use,” she continues, adding that they also refrain from harvesting every truffle. “It is important that the spores are left in the ground so that there will be more truffle for the future.”

“In this game, you have to take what nature provides,” concludes Col Roberts. Stuart Dunbar adds: “The better the health of the orchard, soil, trees, the better the production.”