Term
Brettanomyces
bret-an-oh-MY-sees
Band-Aid, stable, clove
A yeast that lives in barrels and cellars. At a whisper it can add spice; at a shout it strips fruit and smells like a barnyard first-aid kit.
4-ethylphenol is Band-Aid and animal; 4-ethylguaiacol is clove and smoke. Old-school southern Rhône, some Burgundy, and some natural wines wear a little Brett as part of the house. Modern hygiene and sulfur keep it down.
Sensitivity varies wildly. If you smell stable and your friend smells Syrah, you are both telling the truth. Whether it is a fault depends on the dose and the style.
It will not blow off like reduction. Air can even make it louder.
