Let's start with a direct quote from an interview with Martha Stewart:
I learned quite a bit about truffles after helping to organize the 3-day truffle extravaganza back in 2015 for Meals on Wheels Lewes-Rehoboth hosted by Black Diamond Black Truffle Orchards and SoDel Concepts.
During a radio interview, I admitted to the owner of Black Diamond Orchards that I hated truffle oil (regulars here know that is no secret), so I naturally thought I hated truffles too. She corrected me in no uncertain terms: “Truffles and truffle oil have nothing to do with one another,” she stated. I was surprised to learn that most stuff called “truffle oil” never actually met a real truffle. In fact, it's nothing but cheap or mediocre olive oil flavored with a chemical essence called bis(methylthio)methane, classified as an “aromatic” and related to formaldehyde. Not unlike most perfumes, in fact. Those who make and sell it insist that it smells and tastes like truffles, but to me (and to many) it smells like burning rubber mixed with cheap perfume. Yuck.
While in the kitchen at Bluecoast Bethany, Truffle queen Susan Alexander of Black Diamond Truffle Orchards literally forced me to try actual truffles, and they tasted nothing like the nasty truffle oil that otherwise talented cooks and chefs have felt compelled to splash over pretty much everything. So beware! Don't fall for the truffle oil scam!
There I said it. And I feel better. Pass the real truffles, please … thinly shaved and reminiscent of a slightly aromatic mushroom.
(Thank you, Gustiamo.com for the truffle oil image, and SigmaAldrich.com for the chemical info)