Often called the diamond of the culinary world, truffles are actually a specific type of fungus which only grows underground. The white truffle is largely cultivated in Italy, specifically the Piedmont region, from the months of September to December. A short growing season, combined with a highly specific growing region and the difficulty in locating truffles, makes them very expensive to purchase. White truffle-infused oils are more economically priced and are often part of pasta and seafood dishes.
One of the simplest ways to substitute white truffle oil, while still maintaining the distinct taste of truffles, is to use real truffles in place of the oil. Add a few paper-thin slices of fresh white truffle to the dish near the end of the cooking process. Preserved truffles, often available canned or jarred with a flavorful liquid such as brandy, can also be a good substitute.
Black Truffle Oil
Black truffle oil is similar to the white truffle oil, but has a more pungent flavor due to the complexities of the black truffle. While white truffle oil is said to be best suited for light dishes, such as fish, cream sauces and vinaigrettes, the black truffle oil is more often used for red meat dishes. However, the flavor is similar enough that the black truffle oil can be an excellent substitute. Add the truffle oil at the end of the cooking process to prevent the flavor from dissipating, and use slightly less black truffle oil than the amount of white truffle oil called for in the recipe.
Other mildly flavored oils, such as hazelnut, walnut, grapeseed, garlic or even plain, good-quality olive oil can take the place of truffle oil. Drizzling any of these flavored oils into or onto a dish will add a subtle flavoring, although the distinct complexity of the white truffle will be missing.