Lure of the truffle

Sunday, 03 July 2016

Dusty, one of the truffle dogs at Tarago Truffles

What has this gorgeous dog called Dusty got to do with truffles, you might ask? Well, in fact, she and her canine colleague, Utah, play a crucial role in the hunt for these exotic delicacies on a truffle farm, Tarago Truffles, an hour outside of Canberra. Rather than employing the far less manageable 'truffle pig' used in Europe, trained dogs are used in Australia to help find where the truffles are growing, via a sense of smell that seems nothing short of remarkable. There is currently a Truffle Festival going on in the Canberra region, and I headed there last weekend to take part in a truffle hunt and to learn more about the fascinating relationship between the truffle and its host trees.

The truffiere at Tarago Truffles

Though truffles have a long history of cultivation in Europe - back to the time of the Ancient Greeks and Romans - the truffle industry is quite young in Australia. It has been embraced enthusiastically by farmers such as Denzil and Anne Sturgiss at Tarago, where the hot summer/cold winter climate is ideal for growing them. A truffle is a form of fungus: there are unicellular fungi such as yeasts and moulds, as well as multicellular fungi that produce fruiting forms such as mushrooms and truffles. Fungi comprise a separate 'kingdom' from plants and animals, but many fungi have important symbiotic relationships with plants, especially in the form of 'mycorrhizal symbiosis', where the fungus colonises the host plant's roots, in order to access nutrients from the plant. This relationship in turn has an extremely complex function and importance for the host plant's growth and survival in ways that are hard for us to fathom: for example, helping the plant itself to take up nutrients from the soil and be more resistant to diseases and toxins, and even facilitating the exchange of nutrients (and information!) between host plants.

Hazelnut tree, Corylus avellana, at Tarago Truffles

The main truffle currently being grown in Australia is Tuber melanosporum, the French black truffle. It seems to grow best in association with the roots of oak (the English oak Quercus robur and the evergreen or holly oak Quercus ilex being favoured) and common hazelnut (Corylus avellana) trees. To establish a 'truffière', a grove of trees inoculated with the truffle fungus is planted at the right density and in conducive conditions for the root zones of the trees to overlap, to create the optimum environment for the fungi to flourish. The soil needs to be free draining and with a fairly high pH level; irrigation is usually required so that the fungi prosper.

Sniffing for a truffle

The truffles themselves can take a few years to develop. Seeking them out in the truffière becomes the work of the truffle dog and its handler. On the day of our visit to the truffle farm, Dusty nonchalantly trotted through the trees and would suddenly stop and scrape at the ground. Matt, Dusty's owner/handler, who must have an incredible sense of smell himself, crouched down to sniff the spot that had been indicated, and if the odour of the truffle indicated it was ready for harvest, he would start to dig carefully with a spoon to unearth the truffle. We all had turns of sniffing the ground, and I have to confess I couldn't smell a thing!

Truffle from Tarago Truffles

A truffle is a strange and wonderful thing; looking somewhat like a compacted clod of earth, it can vary in size from the dimensions of a squash ball to that of an emu egg! When perfectly ripe, it is quite firm - if overripe, it can get squishy. Inside the truffle, there is a fascinating marbled appearance. The aroma of a fresh truffle is different to what I had expected, with my previous experience mainly limited to truffle oil out of a bottle. As Anne Sturgiss explained to us, commercial truffle oil is made out of a synthetic 'truffle aroma', which is not really like the scent of a fresh truffle at all. After our truffle hunt, we adjourned to the shearing shed for a lunch of delicious homemade soups with fresh truffle generously strewn across the surface, accompanied by bread spread with truffle butter.

We were later shown how truffles are cleaned and graded, and had the opportunity to purchase a truffle to take home. My truffle was divided into three and went back to different kitchens, where over the week it was used in risottos, truffle butter, truffled brie, truffled olive oil and even a vegan 'maca-phoney cheese'! Truffles contain glutamic acid, a flavour enhancer that will add that desirable 'umami' taste to many dishes.

The mysteries of what goes on underground between the truffle fungi and the intricate network of tree roots have piqued my curiosity about the enigmatic secret life and 'intelligence' of plants. I'll be investigating further!