Share

If a wine smells like rotten onions, it could be a sign that what wine flaw is present?

A. Brettanomyces

B. Oxidation

C. Trichloroanisole (or TCA)

D. Mercaptan Compounds

D.

Ok, unless you’re a winemaker, this might have been a tough one. Rotten onion aromas are a sign of mercaptan compounds. These horrible-smelling compounds can be created after fermentation when hydrogen sulfide and other basic sulfur compounds create compounds that smell like rotting onions or spoiled garlic. Brettanomyces usually smells of manure, like a barnyard. Oxidation has a scent reminiscent of rancid nuts. And TCA can be detected by its distinctive odor of a dirty wet dog sitting on wet cardboard in a damp cellar.

Get WineSpeed

Join tens of thousands of other wine lovers. Get each week’s edition of WineSpeed delivered to your inbox every Friday. It’s fast. It’s free. It’s the smartest way to stay up to speed on wine.
Email address
First Name
Last Name
Other Way You Heard About Us
Be sure to check your inbox to confim your subscription.