Truffle Oil: What Is in the Bottle, and Is Home-Made Safe?

The compound 2,4-dithiapentane is naturally an important part of white truffle aroma, but it is also made industrially. In the Greek study it was found at high levels even in oils labelled as black truffle, alongside compounds known from onion, garlic and mustard. The study is small and tied to that market; it does not describe every oil, but it shows why smell is not proof.

With home-made oil the question is safety, not aroma. Oil around pieces of vegetable, herb or mushroom creates an oxygen-free environment in which Clostridium botulinum can form toxin without the product looking spoiled. BfR therefore advises against storing such home-made products, and Health Canada states that prolonged refrigeration alone is not an adequate control. Neither authority names truffles; a truffle is a fungal fruiting body, so we read it as the same case.

What “natural truffle flavouring” means and how the declared truffle percentage is read is explained in how to read a truffle product label.