- Truffle oil is made from truffles, a gourmet variety of mushrooms. It is primarily used in sparse amounts to flavor food, not for cooking. Truffles grow underground and their difficulty to harvest makes them one of the most costly natural food products in the world. Truffles grow all over the world and are generally dug up by pigs or dogs, or harvesters use rakes to uncover them. There are different types of truffles that grow throughout the world, but the most commonly used truffles for oils are black truffles and white truffles. White truffles produce a milder flavored oil; however, black truffles are much more affordable.
- The oil is not extracted or otherwise made from truffles themselves. Once the truffles are harvested, they are wiped with damp towels to remove dirt and debris. They are left unpeeled and raw before being crushed or chopped into tiny pieces. The small pieces of truffles are used to infuse other oil. Mild flavored oils, such as olive oil or grapeseed oil, are optimal for truffle oil production because they don't overpower the subtle truffle flavoring. The crushed truffle pieces are mixed with the oil and left in to flavor it. Some manufacturers may filter out the truffle pieces. Some artisan truffle oil producers use whole truffles to flavor oil and sell them with the truffles still in the bottle.
- Authentic truffle oil isn't as widely used as the synthetic variety; in fact, the majority of chefs do not use real truffle oil in their dishes. Synthetic truffle oil costs a fraction of the price of authentic oil and actually has a stronger truffle flavor than truffle oil made from actual truffles. It is primarily from 2,4-dithiapentane, an aromatic chemical compound that was developed to smell and taste like truffles, according to chef Daniel Patterson in his De Gustibus column in the New York Times. The synthetic flavoring agent is mixed with olive oil or grapeseed oil. These synthetic truffle oils are then packaged into glass bottles and labeled as "truffle flavored oil" or "truffle infused oil."
