I recently bought a small bottle of black truffle oil from a local shop for $20, but didn't use it until a few weeks later. When I opened the bottle (which had been sealed) I sniffed the oil, expecting the rich aroma of black truffles - nothing. It smelled like regular olive oil. Unfazed, I proceeded to add some to my mac & cheese, thinking that perhaps it still tasted fine . . . I added about a fifth of the bottle ($4 worth!) but still nothing. I couldn't even taste it! Now I know that it's not supposed to smell/taste like nothing because I've used truffle oil before, and it's pretty potent - but it's been long enough since I bought the oil that it would be awkward for me to take it back (also, I bought it from a small, locally-owned fine foods shop, and I don't even know if they'll take it back).
Help, chowhounds! What do I do?? What would you do??