When used in cooking, the differences in flavor between white and black truffle oil are extremely subtle. Thus, white and black truffle oil can be used interchangeably. The intense flavor and aroma in truffle oil is created by the use of chemical compounds that mimic those found in real truffles. Truffle oil is often produced by combining an aromatic gas known as 2,4-dithiapentane with olive oil or sunflower oil.
There are some flavor differences between real black and white truffles as dug out of the ground. Black truffles have an earthy taste and pungent aroma, while white truffles have a musky scent with a flavor that has hints of garlic and shallots. Because fresh truffles are expensive and scarce, truffle oil is used as a substitute in many dishes. Artificial chemicals such as 2,4-dithiapentane replicate the natural gases produced by real truffles. Some people dislike the artificial nature of commercial truffle oil, and note that natural truffles produce up to 30 different gases, a complexity of aromas that is hard to duplicate synthetically.
Truffle oil is normally applied to food before serving. A few drops is all it takes to enhance the flavor of dishes. While some truffle oils contain bits of dried truffles, these do not usually contribute to the oil's flavor.