Truffle oil is basically considered an inexpensive alternative to actual truffles. Oddly, truffles are not actually an ingredient in most truffle oils. Truffle oil is made from an olive oil base. Aromatic ingredients are added to mimic the taste of either black or white truffles. The primary ingredient is a synthetic thioether called 2,4 dithiapentane, which produces an odor and flavor similar to real truffles. Other organic aromatics are also added to give a taste closer to either black or white truffles. Actual truffles are insanely expensive, so this less costly alternative is considered by many to be a reasonable option for producing truffle-flavored dishes.
Truffles grow underground in a symbiotic relationship with the roots of certain trees. Black Perigord truffles are named for the region of France where they grow amongst the roots of oak trees. Black truffles have the strongest flavor of all the truffles and a pungent aroma. The smell is so strong it will permeate eggs in their shells, if they are stored together, and change the taste of the eggs. The flavor of black truffle oil, like the truffles themselves, is stronger and more earthy. It is used to flavor liver pates, sauces and savory pastries.
White, or Alba, truffles grow best in northern Italy, in the Piedmont region. Truffles grown in different areas have different tastes since they grow underground and take on the characteristics of the soil they are found in. White truffles have a more delicate taste and a garlicky aroma. They are usually eaten raw, shaved very thinly over risottos, pastas, egg dishes and fondues. White truffle oil can be added to these same dishes.
There is a lot of controversy about truffle oil. Many chefs see it as the only cost-effective way to include the truffle flavor in their cuisine. However others, like San Francisco-based chef, Daniel Patterson, who also writes about food for the New York Times, have complained that truffle oils are ruining the truffle experience. In a 2007 article Patterson wrote, "their one-dimensional flavor is also changing common understanding of how a truffle should taste."
Choosing Black or White
In choosing which truffle oil to use, black or white, you should consider the recipe and other ingredients. Black truffles are always cooked and have a stronger taste, so black truffle oil is a good choice to go with meats, sauces and casseroles.
White truffles are usually not cooked, and have a lighter taste, so white truffle oil is better with eggs, pasta with cheese, risottos and dishes where it will be added after the cooking is completed, such as drizzled over tomatoes and fresh mozzarella cheese.
Truffle oils can cost anywhere from $10 for 1.86 ounces up to $67 for .33 ounces of concentrated truffle oil, made with cold stone pressed olive oil and soaked with actual truffles.