True truffle oil offers an aroma and umami quality to foods unmatched by other flavorings. Much of the truffle oil you buy is not made from truffles, but from chemical compounds that mimic this mushroom-like organism's distinctive qualities. To ensure that your truffle oil is not an imposter, make it yourself. Homemade oil requires an initial investment in truffles, which don't come at a low price, but the results are well worth it.
Acquire very ripe truffles, which emit the strongest aromas. Unripe truffles have no flavor. Black or white truffles are flavorable, but they have slightly different flavors. White truffles are the rarest and most desirable. Use the ripe truffles immediately, as they'll lose their potency quickly.
Heat a cup or 2 of high-quality extra-virgin olive oil in a pot over low heat. Bring up to a warm, but not simmering or boiling, temperature.
Shave or finely dice pieces of the ripe truffle into the warm oil. Transfer to a jar or bottle, cover with a lid or cork and allow the mixture to steep for several hours or days in a cool, dark place. The longer it steeps, the stronger the flavor. For optimal flavor, remove as much oxygen from the container as possible using a nitrogen gas dispenser made for wine enthusiasts. Other methods of minimizing exposure to oxygen include plugging a bottle with a cork and sealing wax or covering the surface of the oil with plastic wrap.