What aroma is commonly described as smelling like cheese or feet?

Isovaleric acid is responsible for the aroma often described as resembling cheese or feet. This compound is a short-chain fatty acid that results from the microbial metabolism of certain compounds, particularly during the fermentation process in brewing and winemaking. Its distinct smell is often associated with intense flavors and aromas in some cheeses and can be perceived in some beer styles, particularly those that are heavily hop-forward or have undergone wild fermentation.

The specific smell of isovaleric acid—often likened to that of sweat or certain aged cheeses—can influence the overall aroma profile of a beverage, especially where yeast or bacteria have contributed to its development. This characteristic aroma is notable enough to be referenced in tasting notes and sensory evaluations.

In contrast, mercaptans are sulfur-containing compounds known for their skunky or rotten smell, trans-2 nonenol is typically associated with fruity or floral aromas, and acetic acid is mainly known for its vinegar-like smell. While each of these compounds contributes distinct aromas to beverages, none evoke the cheese or feet aroma as clearly as isovaleric acid does.