Truffle, Explained: Black, White, Oil, and What “Truffle Ponzu Jus” Tells You

Two lines on our Hamilton Road menu end the same way. The Angus Pure Southern Australian ribeye MB4+ is “300g grain-finished, truffle ponzu jus, salad”, and the Blackmore full blood wagyu karubi MB9+ is “200g full blood wagyu short ribs, 600-day grain-fed, truffle ponzu jus, salad”. Over at Li’l Habibi on Haji Lane, the steak frites come with a “ponzu truffle jus” — the same three words in a different order.

We have written about the ponzu half of that sauce already. This is the other half: what a truffle actually is, why several different things are sold under the name, why most “truffle oil” has never been near one, and what our menu does and does not tell you about the truffle in our jus.

What a truffle actually is

A truffle is the fruiting body of a fungus that does its fruiting underground. The prized culinary truffles belong to the genus Tuber, although the word gets applied to more than a hundred other genera of underground fungi too, some of them worth very little.

Truffle fungi live in partnership with trees. Their threads wrap and enter the fine roots of oak, hazel, beech, poplar and others, trading minerals and water for the sugars the tree makes. That is why truffles turn up at the foot of particular trees, and why cultivation, when it finally worked in France around the turn of the nineteenth century, meant planting the right trees rather than sowing truffles.

The smell has a job. Buried spores cannot travel on wind or rain, so a ripe truffle gives off volatile compounds that attract animals — squirrels, voles, deer, birds — which dig it up, eat it and carry the spores away. The aroma people pay for is the fungus advertising itself to whatever will spread it. Even the name is unromantic: by most accounts it comes from Latin tūber, via Vulgar Latin tufera, a swelling or lump.

Black, summer and white: the ones that matter in a kitchen

The black Périgord truffle (Tuber melanosporum) is named after the Périgord region of France and grows wild in parts of Spain, France, Italy and Croatia. In the Northern Hemisphere it is harvested from November to March. Its scent is described in terms like undergrowth, wet earth, dried fruit and a hint of cocoa, and one detail matters for cooking: its flavour is said to develop fully only once it has been heated.

The summer truffle (Tuber aestivum) is found across Europe, and molecular work in 2004 showed that the Burgundy truffle, long sold as a separate Tuber uncinatum, is the same species. Summer truffles are harvested from May to August and Burgundy truffles from September to December. The aroma is often described as hazelnut-like, and in France and Italy it serves as a milder, less expensive stand-in for the Périgord.

The white truffle (Tuber magnatum) is the tartufo bianco of Piedmont, associated above all with the countryside around Alba and Asti, though a good share of Italy’s white truffles come from Molise. It fruits in autumn and is the species behind the auction stories; the record cited for a single specimen is US$330,000, paid in December 2007 for one weighing 1.5kg.

Why it smells like that, and why pigs went out of fashion

Every truffle species produces sulphur compounds, and dimethyl sulphide among them is the one truffle-hunting dogs and pigs have been shown to respond to. Pigs were the traditional hunters, and the trouble with pigs is that they want to eat what they find. Italy banned pigs from truffle hunting in 1985 because their digging damaged the underground network and cut later harvests; dogs, which do not much care for the taste, can be trained to find without devouring.

The chemistry also explains how truffles are eaten. The aromatic compounds dissolve readily into fat — butter, cream, cheese, oil — and fade with heat and time. So the classic way to eat fresh truffle is shaved raw over something warm, simple and rich, where the fat catches the aroma.

Truffle oil, and the molecule in most of it

The great majority of “truffle oil” is not oil that has had truffles in it. It is oil flavoured with a single synthetic compound, 2,4-dithiapentane — one of the many aroma compounds found naturally in truffles, made in a lab and added on its own. Some bottles include a sliver of truffle for show, which can come from any of a couple of hundred species and still be labelled “black” or “white”.

Artificial truffle oils have been around since the 1980s and labelling rules for the compound are loose, which is why so many chefs are rude about it, and why the Royal Agricultural Society of Victoria’s Australian Food Awards bans the compound from entries in its truffle categories. The practical tip if you are buying a bottle: oils infused with real truffle list the species’ scientific name in the ingredients. If the label says “truffle aroma” or “truffle flavour” and nothing in Latin, you are almost certainly buying the molecule.

What our menu says — and what it does not

We will be careful here. The menu says truffle ponzu jus. It does not say whether the truffle element is fresh truffle, preserved truffle, a paste, a truffle-infused oil or butter, or which species is involved. Every one of those is a legitimate way to put truffle into a sauce, and they cost wildly different amounts. We are not going to guess on the blog. If it matters to you, ask the floor team on the night and they will tell you what the kitchen is using.

What we can say is why truffle, ponzu and beef make sense together, because that part is just how flavour works. A jus carries fat, and fat is what truffle aroma dissolves into. Ponzu brings citrus acid and soy: the acid cuts through the richness so the fifth mouthful tastes as clean as the first, and the soy adds the savoury depth we went into in our piece on umami. Truffle sits on top of all that as aroma. On something as fatty as an MB9+ short rib — the grading is explained in what MB4+ and MB9+ actually mean — you want both the acid and the perfume, not one or the other.

The truffle that grows in the desert

Half of our kitchen’s ideas come from the Levant and North Africa, so this belongs here. There is a whole family of “desert truffles” — the Terfeziaceae, including Terfezia and Tirmania — that grow in arid ground across North Africa, the Mediterranean and the Middle East, usually alongside sunrose plants (Helianthemum). In classical Arabic they are kama’a; in Kuwait, fagga; in Saudi Arabia, faq’h; in Algeria and Tunisia, terfez.

They are a different thing to eat: pale, often tinged pink inside, with far less flavour of their own than European truffles — which is why the Romans, who imported them from Libya, Carthage and Lesbos, used them as a carrier for heavily spiced sauces. They cannot be cultivated, and they are much cheaper than the European kinds. They are not on our menu and we are not claiming any link with our jus. They are simply a reminder that “truffle” has always meant more than one thing.

One last piece of context, since both of our beef cuts are Australian: black truffles are now farmed in the Southern Hemisphere too — New Zealand’s first were harvested in Gisborne in 1993 and Australia’s in Tasmania in 1999 — and a winter crop down there arrives in Europe’s off-season. Our menu does not say where its truffle comes from, and we are not implying that it is Australian.

Where to find it on our menus

For the wider picture of how the Japanese pantry runs through our cooking, start with our full guide to Japanese food in Singapore. And if you would rather find out what the truffle in the jus is by asking over a plate of it, book a table — Habibi-san is at 29 Hamilton Road, open Tuesday to Sunday from 5pm to 11pm.

Sources: Wikipedia, “Truffle”, “Tuber melanosporum”, “Tuber aestivum”, “Tuber magnatum”, “Truffle oil” and “Desert truffle”, read 2 October 2026. Menu wording quoted from the live Habibi-san food menu and the Li’l Habibi menu, both checked unchanged on 2 October 2026.