Truffle

What is a truffle?

Truffle is the name for fungi in the genus Tuber that form their fruit bodies underground as tubers and live in partnership with tree roots. What we eat is the fruit body: there is no cap, stem or gills, and the inside is marbled with white veins. Ripe truffles give off a strong smell that attracts the animals that spread their spores.

There are many Tuber species worldwide; the best known in the kitchen are the Périgord black truffle (Tuber melanosporum), the white truffle (Tuber magnatum) and the summer truffle (Tuber aestivum). This page covers the whole genus, with separate notes on the summer truffle, the most common in Turkey, and the much-searched white truffle. Domalan, which grows on dry steppe, is a separate genus; see our desert truffle page.

How do you recognise the summer truffle?

The summer truffle is black on the outside, covered in small pyramid-shaped warts, with a hazel-brown inside marbled with white veins. Wikipedia gives its size as 2–10 cm and rates it as an excellent edible. The autumn form of the same species, darker inside and stronger smelling, is known as the Burgundy truffle (formerly Tuber uncinatum).

The summer truffle is the truffle with most records in Turkey. Our map has observations from Istanbul, and one of our photos was taken by an observer in Turkey. It is known to grow with oak, hazel and beech and was also recorded in the Denizli study.

Is there white truffle in Turkey?

We found no confirmed record of the white truffle (Tuber magnatum) in Turkey; the species is best known from Piedmont in Italy, around Alba and Asti. Wikipedia also lists Croatia, Switzerland, south-east France, Hungary, Serbia, Slovenia, Greece and Bosnia and Herzegovina.

The white truffle has a smooth, ochre-cream skin and a cream to pale brown inside with white veins; according to Wikipedia it can reach 12 cm and half a kilogram, although most are much smaller. It lives mostly with oaks and secondly with white poplar, and has also been reported with willow, beech and elm. It needs neutral to alkaline soil and cold winters, and copes with summer drought less well than black truffles.

Pale truffles sold as white truffle in Turkey are usually other Tuber species; Tuber borchii, for example, is a pale truffle recorded in Turkey. Exact identification needs a microscope or DNA.

Black, summer and white truffles: what is the difference?

Skin, inside colour, season and smell separate the three. The Périgord black truffle (Tuber melanosporum) has a black, warty skin and a purple-black inside with white veins when ripe; it is a winter truffle. The summer truffle also has a black, warty skin, but its inside stays hazel-brown and it smells milder; it is gathered in summer and autumn. The white truffle has a smooth, pale skin, a cream to brown inside and the strongest smell, and ripens in autumn.

Most species recorded in Turkey are summer truffles and similar black-skinned truffles. Because the Périgord black truffle and the summer truffle look alike from outside, they are told apart by cutting and, if needed, under a microscope.

Where do truffles grow in Turkey?

In Turkey truffles grow in forests dominated by oak and hazel, on calcareous, well-drained soils. Scientific records come from Denizli, the Marmara region, Thrace and eastern Anatolia; a 2016 paper by Elliott and colleagues in Mycotaxon added eight new truffle records from Anatolia. GBIF also has Tuber macrosporum records from Thrace.

The six truffle observations on our map are from Istanbul and Kırklareli; see every record on our mushroom map. We describe the forests and suggested routes in our article on where truffles grow in Turkey. Oaks in a forest do not mean there are truffles, and because records are few, an absence is not certain either.

How are truffles found?

Because truffles grow underground they are found by smell, today mostly with trained dogs. Research cited by Wikipedia shows that the main scent compound recognised by dogs and pigs is dimethyl sulphide. Sows were used in the past, but pigs tend to eat truffles and dig up the ground, and using pigs to hunt truffles has been banned in Italy since 1985.

Dogs do not eat the truffle, they mark the spot and do less damage to the soil. We explain training in our truffle dog article. Hunters without a dog look for the burnt-looking ring of thin grass around a tree and for truffle flies, but these signs are not reliable.

Are truffles poisonous, and what are they confused with?

The true truffle species collected for sale are edible; the danger is mistaking a poisonous tuber for a truffle. The best-known example is the common earthball (Scleroderma citrinum). According to First Nature, although reports on its toxicity conflict, it should be treated as poisonous and looked at, not cooked.

The earthball usually grows on the surface or half buried; it has a thick, scaly skin and an inside that is white, then purple-black and unveined, turning to powder when ripe. A true truffle is veined inside and has its own smell. In Europe the pig truffle (Choiromyces meandriformis) also resembles a truffle and has been reported to cause poisoning. Our poisonous mushrooms page lists the dangerous species.

Can truffles be cultivated?

Truffles cannot be grown at home, in pots or from a kit; orchards are planted with seedlings whose roots are inoculated with truffle mycelium, and harvests come after years. Wikipedia notes that the first Tasmanian harvest came after eight years of work with inoculated trees.

Turkey has public projects too: according to a 2016 CNN Türk report, the General Directorate of Forestry's Truffle Forest Action Plan for 2014–2018 aimed to plant 395 decares of truffle forest and to train collectors. We describe how orchards are set up in our truffle growing article; for species that grow at home see our grow at home page.

Do you need a permit to pick truffles in Turkey?

Picking truffles and other mushrooms from state forests for sale requires permission. Non-wood forest products in state forests are managed under Forest Law No. 6831 and General Directorate of Forestry rules, and the local forest enterprise office is the body to ask about commercial picking. The action plan also aimed to stop random digging by training volunteer collectors (CNN Türk). More detail is in our article on where truffles grow; we do not quote prices here, but our most expensive mushroom article covers that topic.

How are truffles used in cooking?

Truffles are used sparingly because of their price and strong aroma; according to Wikipedia, the volatile aroma dissipates quickly with heat, so they are usually shaved raw over warm, simple dishes such as buttered pasta or eggs. The aroma compounds carry well in fats such as butter, cream and cheese, and slices also go into meat, under the skin of roast poultry, and into pâtés and stuffings. Urbani says black truffles also work heated, while white truffles are best used fresh and thinly sliced over a dish. Our truffle tagliolini uses this method and takes fifteen minutes.

Truffles are not washed but cleaned with a soft brush. Following Urbani's advice, wrap them in dry kitchen paper, keep them in a sealed glass jar in a low-moisture part of the fridge and change the paper daily; stored this way white truffles last 3–4 days and black truffles 5–6 days. A little mould on the skin is natural and brushes off.