Understanding the 10 defective smells that could compromise your wine experience

The human nose is an unparalleled detector of subtleties in aromas, and when it comes to wine, olfactory senses play a crucial role. The aromatic experience can account for as much as 80% of the pleasure derived from uncorking a bottle. Yet, this experience can also turn bitter if met with unwanted aromas—odors that often tamper with the wine's inherent qualities, and can even render it undrinkable. This article aims to provide an in-depth analysis of the ten key aromas that signal defective wine.

Herbaceousness Over Herbal Qualities

When describing a pleasant green note in wine, one might use the term 'herbal.' However, an excess of this green note—referred to as 'herbaceous'—is usually a sign of an issue in the production process. This could stem from the crushing, destemming, or pressing of the grape or cluster, leading to the inclusion of immature leaves and stems. Preventing such inclusions during harvest is essential for avoiding this unwanted aromatic quality.

Brett: A Double-Edged Sword

Brett, or Brettanomyces, is a controversial element in the realm of wine aromas. In small amounts, some consider it to add complexity to the wine. Yet, when excessive, it produces a musty, damp, or unclean scent, often due to poor hygiene in the winery. Excessive Brett also increases acetic acid levels, making the wine unpalatably acidic.

The Sting of Bitter Almonds

A pungent aroma akin to bitter almonds could indicate that the wine has come into contact with air post-racking, bottling, or pumping. This smell can be considered a red flag, signaling that the wine has likely oxidized during its movement within the winery.

Cork Taint: A Universal Problem

One of the most prevalent defects, cork taint can affect even wines from the most prestigious wineries. Characterized by moldy, damp cork, or musty wood and paper scents, this defect originates from chlorinated molecules found in various winery elements, such as cork, cardboard, and wooden barrels. Though often associated with TCA (trichloroanisole), cork taint can stem from various sources.

The Fumes of Glue

Triggered by the presence of ethyl acetate, this defect renders a wine smelling of solvents or varnish. This compound is a result of acetic acid reacting with ethanol. Thus, higher levels of acetic acid increase the likelihood of ethyl acetate formation, a problem somewhat mitigated by higher alcohol levels, residual sugars, and lower acidity.

Rotten Egg and Its Kin

A smell likened to rotten eggs, or other odors like rubber, onion, or cheese, falls under the category of defective thiols. These often emerge from excessive use of sulfur dioxide in winemaking, commonly utilized as a wine preservative.

The Deception of Apple Aromas

While a fresh apple aroma might be expected in certain wines like Old World Chardonnays, an aged apple smell is a tell-tale sign of oxidation and is unacceptable.

The Decay Hidden in Sweetness

Especially prevalent in sweet wines, the scent of geraniums can indicate lactic bacteria's attack on sorbic acid, used to prevent refermentation. Initially subtle, this aroma can evolve into a putrefying smell if left unchecked.

Acetic Acid: A Common Culprit

Also known as 'vinegar taint,' this defect arises from excessive acetic acid, generally when wines are poorly sealed or exposed to air. A leading cause is poor hygiene within the winery.

Earthy Dampness: Not Always Elegant

Sometimes mistaken for the earthy notes in some elegant Burgundy wines, a damp, earthy smell usually results from wine production in overly humid or rainy conditions.

Knowing what to sniff out can make the difference between an exquisite and a regrettable wine experience. Understanding these ten undesirable aromas provides an arsenal of knowledge for any wine enthusiast, contributing to a more informed and enjoyable indulgence in the world of wine.