What are truffles
Truffles are the edible fruiting bodies of a type of subterranean fungus known as a Mycorrhiza (“root fungus”), which form symbiotic relationships with a host tree.

Black truffles are harvested in winter so fresh truffles are available from late June through to the end of August.
Truffles vary in size and shape. They typically range in size from that of a small nut to the size of a tennis ball and appear rounded with a knobbly surface. The fully ripe truffle interior is black with a distinctive white marbled pattern.

The truffle coats the tips of the tree roots to form mycorrhiza which act as an extension of the tree's root system.

The tree provides the truffle with a source of photosynthesised carbohydrates, and in return the fine, thread-like filaments (mycelia) of the truffle, extract and trade soil minerals and nutrients which would normally be unavailable to the tree.

Thus the mycorrhiza is able to increase the effectiveness of the trees roots, enabling the tree to grow in soils which would normally be too nutrient deficient to support them.

Culinary Uses
Truffles have a pungent aroma that can be loosely described as of ‘fresh earth’ and sweet mushrooms. Throughout history people have constantly failed to adequately describe the aroma and flavour of a premium truffle, contributing to the mystique of this exotic fungi. Their taste can permeate and enhance many foods such as soups, dips and patès, salads, sauces, dressings, omelettes and main meals. The irresistible allure of their unique aroma, flavour and taste accounts for their gourmet status, and demand by consumers, and makes them a highly valued ingredient.

Host Trees
The famous, highly prized, French Black Truffle is botanically named Tuber melanosporum and lives on several host species of Oaks and Hazel trees. The most commonly used tree species are as follows:

• English Oak (Quercus robur) Deciduous tree growing to about 20 metres. However, in a truffière their height is much reduced by competition and pruning
• French Oak (Quercus ilex) - also known as Holm or Holly Oak. Evergreen tree growing to about 10 metres
• Cork Oak (Quercus suber) Evergreen tree growing to about 10 metres
• Hazelnut (Corylus avellana) Deciduous small tree or large shrub branching from base growing to about 5 metres, producing edible hazelnuts. See our website dedicated to growing hazelnuts for information of varieties, etc hazelnuts.com.au
• Stone Pine (Pinus pinea) conifer growing to about 10 metres and famous for producing the edible pine nuts

French Oak (Quercus ilex) 

English Oak (Quercus robur)

 Stone Pine (Pinus pinea)

Hazelnut (Corylus avellana)

Truffle Varieties
There are many types of truffles used for culinary purposes. The main truffle types are:

• French Black or Périgord truffle (Tuber melanosporum): This is the famous black truffle also known as the “Périgord”, named after that region in France. It is highly aromatic and has high culinary value with chefs and restaurants. The vast majority of the truffles that are grown in Australia are this one. It harvests in winter (typically June through to the end of August). It has a black peridium (skin) and the glebra (fruit body) is black with thin white veins. 
• The Burgundy or summer truffle (Tuber aestivum/uncinatum) from Central Europe, Turkey and North Africa. This is another black truffle but harvests in summer (typically late January to early March). It has a black peridium (outer skin) but a pale coloured gleba (fruit body). The aroma is slightly sweet, earthy, mild and is much less pungent than that of T.melanosporum. 
• The Bianchetto (little white) truffle (Tuber borchii) from Tuscany. In its homeland it is frequently found on Italian stone pines but also grows on oaks and hazelnuts. The harvest period in Australia is May through to September. It has slightly garlic aroma and is similar in colour and aroma to the famous Italian white (T.magnatum) but is of less culinary value. Due to the scarcity of T.magnatum it still commands a high retail price. 
• and finally, regarded as the ultimate truffle by some, The Alba White Truffle, (Tuber magnatum) from the Piedmont region of Italy). Unfortunately, no cultivation of this truffle has been successful to date

Tuber melanosporum French black truffle

Tuber aestivum Summer black truffle

Tuber borchii Bianchetto white truffle

Life Cycle
The truffle fungus colonise the new root growth in spring and the developing mycelia spread out in the soil. From about January the tiny truffle sporophytes begin to develop (through a sexual process) and grow to maturity during the June, July and August period. Obviously, there are specialised growing conditions (temperature, soil moisture, pH and nutrition) that need to be maintained to optimize the likelihood of truffle development.
It should be noted that the exact environmental triggers that affect truffle initiation and development and the process are not clearly understood. This is still the subject of much ongoing research and development.
Growers have reported harvesting truffles at four years but more commonly production starts at around six years after planting and then increases each year. Of course, oak trees are very long lived so with proper truffière maintenance, truffles can continue to be harvested over many decades.

History of truffles
Truffles are native to the Oak and Hazel forests of Europe, especially Italy and France. The Périgord region of southern France is famous for the French Black truffle. Truffles were harvested for hundreds of years traditionally using a pig with its acute sense of smell. In modern times, due to safety and handling issues, most hunters have replaced pigs with dogs.
In Europe the harvest yields have been steadily declining over the last hundred years from around 1000 tonnes in 1900 down to about 50 tonnes per year now. The reasons for this may be to do with urbanisation, two world wars, increasing acid rain and indiscriminate harvesting methods.
Only in the last twenty years or so has a concerted effort been made to artificially grow these in a farming sense. Science is now assisting in providing improved methods of inoculating tree seedlings and improved agronomy and cultural advice.
Truffles are one of the most highly sought after and valued foods in the world and this strong demand and unfulfilled supply has caused a steepening of prices. Grade A truffles retail for more than $2,500 per kilogram making them one of the world’s most expensive food crops.

The industry in Australia
Truffles are a relatively new crop in Australia. Plantings (known as truffières {truffle orchards}) began in the 1990’s in Tasmania and Western Australia with the first truffles being harvested in 1999. Truffières are now established and producing in Victoria, New South Wales, the ACT, South Australia and southern Queensland.

Marketing Potential
Truffles (especially the French Black) are harvested during winter, which of course is six months apart from the harvest period in the northern hemisphere (January and February). This means the Australian and New Zealand markets are not competing with Europe for fresh truffles. This opens an enormous opportunity for export into Japan, China, Europe and the USA.

Clean and Green Industry
Establishing a truffière on Australian soils generally requires heavy amelioration with lime to raise the pH to 8. In Australia we don’t have other Tuber (truffle) species in our soils so this is a big advantage for Australia because in many European truffières, where the soils are naturally alkaline, there can be several competing mycorrhizae established.
The Chinese truffle (Tuber indicum) and also Tuber brumale are similar looking truffles to the French Black however have a poor culinary reputation and are of low economic value. These remain a major danger to our industry if they were to become established. The Australian Quarantine Inspection Service (AQIS) is not allowing the importation of these culinarily inferior truffles.
The Australian Truffle Growers Association conducts a certification/evaluation program to ensure the truffle inoculated seedlings are adequately colonised with the desired truffle species. Trufficulture fully supports this program.