HOW TO IDENTIFY WINE FAULTS?
A wine can present numerous faults during the final tasting phase, making this step crucial for any knowledgeable or passionate wine enthusiast. Here’s how to detect these imperfections that can alter the tasting experience. Wine faults can manifest in three distinct phases:
- The visual test
- The olfactory test
- The gustatory test
Some of these anomalies can appear during one or more of these tests. Beyond simple criteria of “good” or “bad,” there are objective markers indicating a defect in the presented wine. The consumer may reject this anomaly or, in some cases, appreciate it for its unique character. Let’s explore in detail the main wine faults that can be identified during tasting through these three tests.
VISUAL FAULTS IN WINE
Clarity Cloudy wine The clarity of a wine is sometimes compromised by the presence of a haze. This haze, a visual indicator of a wine fault, can have various origins. It is a real fault when there are issues during vinification, the harvest was “rotten,” or the vine was diseased. Although this phenomenon is less observed thanks to modern techniques, a wine can also be cloudy when it has not been filtered, typical of natural wines. In this case, the presence of tartaric crystals or sediment that the winemaker did not find necessary to remove can be perceived as a visual imperfection.
Unexpected effervescence in still wine If, after shaking and successive resting of the wine, small bubbles persist in the glass, this indicates an unwanted secondary fermentation. This re-fermented wine has an undesirable fermentative character, reminiscent of cider, and is a notable fault.
OLFACTORY FAULTS IN WINE
Uncontrolled oxidation Over-oxygenation of wine is a major fault often due to slow and prolonged exposure of the wine to air. This occurs during barrel aging after fermentation. One will smell notes of green walnut, overripe fruits like apple, or even rotten apple. Controlled oxidation is not a fault and can even be sought in certain wine styles, such as fortified wines (Port, Sherry, VDN). However, oxidation in a table wine is irreversible and generally undesirable.
Reduction, the opposite of oxidation: Reduction is the opposite phenomenon of oxidation, resulting from a lack of oxygen in contact with the wine. This fault manifests as unpleasant odors of cabbage, boiled onion, or rotten egg in extreme cases. Fortunately, aerating the wine for 15 to 30 minutes or swirling it can often eliminate these sulfurous odors.
Cork taint, the most common wine fault: Cork taint, caused by a molecule called TCA (trichloroanisole), is a frequent fault. This cork taste in wine can come from contamination of the cork, the storage area of the wine, or a fault during bottling. Musty, mop, or wet cardboard aromas are the distinct signs.
Volatile acidity, a delicate balance: When present in large quantities, volatile acidity becomes a fault. The classic example is acetic spoilage, which turns wine into vinegar at an advanced stage. This fault is caused by acetic bacteria producing acetic acid in contact with oxygen. Caution is needed with already opened bottles.
Brettanomyces, an animal signature: Brettanomyces, or “Brett,” is characterized by an intense animal odor in the wine, sometimes described as horse sweat. This deviation, due to the yeast of the same name during fermentation, is often undesirable. However, some wine lovers may tolerate or even appreciate this characteristic, although winemakers generally seek to avoid its occurrence.
GUSTATORY FAULTS
Most of the above-mentioned faults detected by our sense of smell are, of course, found in the taste of the wine. There are other wine faults as well:
Excessive bitterness: This bitterness is often due to an excess of plant material in the wine (stems and leaves), which can make the tasting unpleasant.
Metallic taste: A pronounced metallic taste in some wines, caused notably by wine reduction, is another gustatory imperfection.
Phenolic compounds: Malolactic fermentation can also lead to the presence of phenolic compounds in red wines, contributing to animal odors.
All these faults have varying detection thresholds depending on the individual. Thus, a wine may present numerous faults to person A and be barely detectable to person B. Ultimately, like human relationships, a wine’s fault can be perceived as a quality by another person… but only to a certain extent! The appreciation of wine faults remains subjective, but knowing these faults allows for more enlightened and critical tasting.