Definition - What does Musty mean?
Musty is a wine term describing the "musty", damp and stale aroma or flavor found in some wines. It is most commonly the result of Cork Taint and the chemical TCA. When this is the case, the musty aroma will overpower the senses and leave nothing left of the wine’s original aromas. Musty aromas and flavors are wine faults, and most wine experts recommend that you return the wine.
WineFrog explains Musty
When caused by Cork Taint, musty characteristics are often coupled with the smell or taste of wet dog, a dark basement, closed up attics, mold and damp, soggy cardboard. The smell will override any other aromas normally found in the glass, making you feel like you stuck your nose in a wet cardboard box. When this happens, toss the wine either by returning it to your waiter or the store.
Other characteristics similar to musty are barnyard and earthy aromas. Though somewhat similar in nuance, the barnyard and earthy aromas are positive characteristics – they don’t overpower all of the natural aromas and flavors in the wine. Instead, they work with the other qualities in the wine precisely because they are naturally occurring characteristics.
There are a few cases where Cork Taint does not cause a musty smell or flavor. When the smell is closer to “musty oak” or “wet wood”, then the oak barrels caused the smell – either the barrels that held the wine were musty themselves, or there were some complications with storage. This smell does not necessarily mean the wine is bad, just off. Another possible cause is old bottles. If you pour a wine from a bottle that has been left in a musty cellar for years, the wine in the glass may exhibit some musty characteristics. These will pass as the wine aerates in the glass or if the wine is decanted prior to serving.
The best way to identify if the musty characteristics are from Cork Taint or storage is to wait to see if the characteristics dissipate. If they do, the wine is ready to enjoy! If they don’t, return the bottle.