What is Truffle Oil?

Firstly, What are Truffles?

Not to be confused with chocolate truffles, the truffles we speak of are actually mushrooms. In the fungus family, Tuberaceae, truffles are an underground version of the mushrooms you normally see growing aboveground. Like all fungi, truffles cannot photosynthesize like plants can, so they rely on mutualistic relationships with trees. The filamentous network that fungi grow for absorbing water and nutrients from the ground is co-opted by nearby tree roots to siphon some of those resources. In turn, some of the sugars produce by the trees via photosynthesis are taken by the fungus to grow. This is called mutualism, as both species benefit from the interaction. 

What do Truffles Look Like?

Truffles look like something in between a small potato and a pinecone. The cocoa-dusted chocolate truffles you may be familiar with are actually made to look like a truffle freshly plucked from the earth. The gourmet truffles, white and winter black truffles in the genus, Tuber, are typically found underground in the forests of France and Italy. These are the most sought-after fungi in the world and their price tag reflects their rarity. Their distinct odour - actually a gas they give off - can be detected by mammals such as dogs and pigs, which is why these animals are employed by truffle hunters to locate the fungus. The reason this gas is given off by the truffle is because its reproductive spores cannot be spread in the air the way above-ground mushrooms can spread theirs. Instead, they send gaseous signals out to animals, which are the primary vector for spore transmission to other parts of the forest. Yum!

How is Truffle Oil Made?

Now, you are likely wondering how a mushroom can produce an oil. In truth, they do not produce oil the way that olives or avocados and the like, do. Rather it is the unique flavour of the gaseous compounds that we try to harness, and to do that, the truffles - or their flavour - must be infused into an existing oil. So no product you see labelled as a truffle oil is actually oil extracted from a truffle; such a thing does not exist. But the natural flavour of the truffle can be added to olive oil to make a gourmet truffle flavoured oil. It is a coveted process, as truffles are incredibly expensive due to their rarity and delicate nature, and the price tag reflects the commodity. However, you only need a small amount of truffle oil to get that really intense earthy truffle flavour, so use sparingly!