Detecting Spoiled Wine

Wine, a beverage revered for its complexity and flavor, can occasionally fall prey to spoilage, transforming into an undesirable state commonly referred to as "wine spoilage" or "acetification." This condition, largely due to the activity of acetic bacteria, presents a challenge for both connoisseurs and casual drinkers alike. Understanding the science behind this transformation and the methods to detect it is crucial for any wine enthusiast.

The process of wine turning into vinegar involves a type of bacteria known as Acetobacter. These aerobic bacteria thrive in the presence of oxygen, forming films of varying appearances on the wine's surface. The chemical equation for this transformation is straightforward: alcohol + oxygen + acetic bacteria = acetic acid. This spoilage can happen at any time and, if detected too late, becomes irreversible.

Detecting Spoiled Wine

To identify a spoiled wine, the key factors are its taste and smell. A wine that unmistakably smells and tastes like vinegar is clearly in a state of spoilage and should be returned or exchanged. However, the challenge arises when the transformation isn't complete, and the acetic acidity is so mild that it could be mistaken for the wine's natural volatile acidity.

When assessing a potentially spoiled wine, consider the following:

• Visual Inspection: A turbid appearance or a film on the surface, especially noticeable when the wine is still and under light.
• Olfactory Analysis: The presence of rotten apple notes, chemical odors like glue or nail polish remover, or subtle nutty scents, can indicate spoilage.
• Taste Profile: A non-fruit acid presence, harshness from ethyl acetate, and acetic acid are warning signs.

Preventing Wine Spoilage

Proper wine storage and handling are key to preventing spoilage. This includes protecting the wine from air exposure, using correct production and preservation techniques, and appropriately employing sulfites.

Seven Warning Signs Before Purchasing:

1. Open Bottles in Bars: Bottles simply resealed with their original cork.
2. Wine in Non-Specialized Establishments: Wine stored in climate-controlled conditions but in places not specializing in wine.
3. Capsule Convexity: Indicating air presence between the capsule and cork.
4. Cork Condition: Anomalies in cork protrusion or capsule shape.
5. Improper Storage Conditions: Exposure to high temperatures, vibrations, and electronic devices.
6. Abnormal Liquid Level: A significant gap between the liquid and the cork.
7. Age of the Wine: Young or crianza wines beyond five or six years from their vintage.

Health Implications of Drinking Spoiled Wine

Consuming spoiled wine, while not pleasant, is generally not harmful. The primary component, acetic acid (vinegar), is not toxic in small quantities but may cause minor digestive discomfort.

Corked Wine: A Different Issue

While screw-top and synthetic corks don't have this issue, traditional cork closures can lead to a different kind of spoilage, often termed "cork taint." This is primarily due to a compound called 2,4,6-Trichloroanisole (TCA), which imparts a musty, moldy smell to the wine, distinct from the vinegar-like smell of acetification.

The art of wine appreciation includes not just the enjoyment of its flavors but also the knowledge to identify when it has gone awry. Understanding the signs of spoilage, whether due to acetification or cork taint, is essential for any wine lover, ensuring that each glass poured is a testament to the wine's intended quality and character.