Parker Points Explained: Understanding Wine Evaluation

Understanding how wine is evaluated and scored is crucial for interpreting any critic's assessment, including prominent systems like Parker points. Wine tasting involves a systematic sensory examination and evaluation. It typically progresses through four recognized stages: appearance, aroma, palate sensations, and the finish, or aftertaste. These stages collectively help establish a wine's complexity, character, and potential, while also identifying possible faults. Professional tasters and competition juries employ structured score sheets and specific descriptors to assess wines objectively. For example, the OIV standard for international wine competitions uses a 100-point scale, with awards like Grand Gold requiring at least 92 points. While specific methodologies vary among critics, the underlying goal is to provide a consistent framework for judging wine quality. This article explores the common elements of wine evaluation, providing essential context for how various scoring systems, including Parker points, are derived and interpreted.

How are wines evaluated in general?

Wine evaluation is a structured process designed to assess a wine's quality, character, and potential. The Court of Master Sommeliers' deductive tasting format, for instance, breaks down evaluation into sight, nose, and palate structure. A detailed palate assessment follows, then an initial and a final conclusion. This comprehensive approach allows tasters to identify specific attributes and potential flaws. The overall quality assessment rests on careful description and comparison with recognized standards. That judgment weighs factors like region, vintage, winemaking techniques, and whether the wine is typical of its region or diverges in style.

To ensure impartiality, wines are often served blind, meaning tasters have not seen the label or bottle shape. A taster's judgment can be prejudiced by knowing details like geographic origin, price, or reputation. For example, French researcher Frédéric Brochet found that tasters described the same mid-range Bordeaux as "woody, complex, and round" when labeled as a grand cru, but "short, light, and faulty" when labeled as a cheap table wine. This highlights the impact of expectation on perception.

What visual cues do tasters look for?

The visual assessment of a wine provides important initial clues about its condition and style. Tasters look for clarity, visible sediment, and the intensity and primary color of the wine. The Court of Master Sommeliers' deductive tasting format details each of those cues. For white wines, colors can range from water white to straw, yellow, or gold. Secondary colors include silver, green, copper, gold, or brown. Red wines can appear purple, ruby, or garnet, with secondary colors including blue, magenta, ruby, orange, garnet, or brown. Rim variation and staining are also noted for red wines.

The OIV standard for international wine competitions includes "Limpidity" and Aspect other than limpidity as visual criteria on its score sheet. Limpidity measures cloudiness, with an "Excellent limpidity" scoring 5 points on the OIV-UIOE still wine sheet. The aspect evaluates intensity, main color, nuances, and viscosity. Sweeter wines are denser. When swirled, they leave thick, viscous streaks down the inside of the glass. Those streaks are known as legs or tears. Gas evidence is also observed, particularly in still wines where it might indicate an unintended secondary fermentation.

How is a wine's aroma assessed?

The nose, or bouquet, of a wine is a major determinant of perceived flavor and is crucial for assessing quality and identifying faults. The Court of Master Sommeliers' format includes assessing aromatic intensity (delicate to powerful) and age (youthful, developing, vinous). Tasters identify fruit aromas (e.g., tart citrus, red fruit) and their condition (e.g., ripe, dried, oxidized). Non-fruit aromas can come from the grape (e.g., green bell pepper, eucalyptus) or winemaking (e.g., bread dough, butter, toast). Earthy notes (e.g., forest floor, potting soil) and mineral notes (e.g., wet stone, flint) are also assessed. The presence and type of oak (e.g., toast, vanilla, cinnamon, clove) are noted, distinguishing between French, American, or Eastern European oak.

The OIV score sheet for still wines includes "Genuineness," "Positive intensity," and "Quality" for the nose. Genuineness measures the presence of viticulture or oenological defects, such as volatile phenols or oxidation. Positive intensity evaluates the magnitude of qualitative odors, while quality assesses the richness and finesse of the aromatic palette. Gently swirling the wine exposes it to oxygen and releases aromatic molecules. That is what best reveals the bouquet.

What defines a wine's taste and structure?

The palate assessment involves a complex array of taste and mouthfeel attributes. The Court of Master Sommeliers' format evaluates palate structure. That covers sweetness (bone dry to lusciously sweet), acidity (low to high), alcohol (low to high), and body (light to full). Phenolic bitterness is noted for white wines, while red wines are assessed for tannin volume (low to high) and texture (silky, gritty, hard). Texture descriptors like creamy, round, or viscous are also used. Tasters confirm fruit, fruit condition, non-fruit, earth, mineral, and oak notes from the nose, noting any changes on the palate. Balance, length of finish, and complexity are also evaluated.

The OIV score sheet for still wines includes "Genuineness," "Positive intensity," "Harmonious persistence," and "Quality" for the taste. Harmonious persistence measures the length of residual olfacto-gustatory sensation after the wine leaves the mouth, calculated in seconds. Quality for taste takes into account richness, integrating aromas, structure (acid, tannins, alcohol), coating elements, residual sugars, and bitterness. Acidity is a dominant player in food and wine pairing. It can heighten flavor perception and stimulate appetite. Sweetness in wine, determined by residual sugar, can balance spice and heat in food. It can also contrast with salt, such as the pairing of Stilton cheese with Port. Tannins, which contribute astringency, react with proteins and fats in food, making them seem softer when paired with red meat or hard cheeses.

What are common wine faults and taints?

Wine faults and taints are undesirable sensory characters that can significantly impact a wine's quality. The Australian Wine Research Institute (AWRI) provides a comprehensive list of these issues.

Oxidation-type faults:

• Oxidation: Causes dulling of aroma, 'cardboard', 'straw', 'hay-like', 'sherry-like', or 'madeirised' aromas. In extreme cases, 'wet wool' or 'varnish-like' aromas can be evident.
• Acetaldehyde: Above 125 mg/L, imparts 'over-ripe bruised apples', 'stuck ferment', 'sherry', and 'nut-like' characters.
• Volatile acidity (VA): Primarily acetic acid, perceived as vinegar. The legal maximum in Australian wines is 1.5 g/L, excluding SO2. The aroma threshold can be as low as 0.1-0.125 g/L, but is usually considered detrimental above 0.7 g/L.
• Ethyl acetate: Perceived as nail polish remover, with a sensory threshold of 12 mg/L. Concentrations of 150-200 mg/L are considered defective.

Reductive wine faults:

• Hydrogen sulfide (H2S): 'Rotten egg gas' aroma, with a detection threshold of 1-2 µg/L.
• Unwanted sulfhydryls (thiols/mercaptans): 'Cabbage', 'garlic', 'onion', 'rubber' aromas. Ethyl mercaptan has an 'onion-like' and 'rubber-like' aroma (threshold 1.1 µg/L). Methyl mercaptan smells like 'rotten eggs' and 'cabbage' (threshold 0.02-2.0 µg/L).
• Disulfides: Oxidized forms of sulfhydryls. Dimethyldisulfide (DMDS) smells like 'onions' and 'cooked cabbage' (threshold 29 µg/L). Diethyldisulfide (DEDS) smells like 'burnt rubber' and 'garlic' (threshold 4.3 µg/L).
• Dimethyl sulfide (DMS): At high concentrations, described as 'asparagus', 'cooked corn', 'cooked tomato', or 'molasses' (threshold 30-60 µg/L).

Additive-related faults:

• Sulfur dioxide (SO2): Pungent, penetrating aroma causing sneezing or choking sensation if too much is added. A content of free sulfur dioxide up to 15 mg/L has no adverse sensory effect. Australia sets a legal maximum of 250 mg/L total SO2 in products with less than 35 g/L sugars. Other products may reach 300 mg/L.
• Diacetyl: At high levels (>5 mg/L), the 'buttery' or 'butterscotch' aroma can be objectionable.
• Geranium: Caused by 2-ethoxyhexa-3,5-diene, with an odor reminiscent of crushed geranium leaves. Its detection threshold is <1 ng/L, making it practically impossible to remove.

Brettanomyces faults:

• 4-ethylphenol: Major spoilage compound, imparting 'Band aid®', 'medicinal', or 'pharmaceutical' character. A concentration of 425 µg/L has a negative impact on quality. The aroma threshold is 368 µg/L in a neutral red wine, according to AWRI sensory studies.
• 4-ethylguaiacol: 'Clove', 'spicy', or 'smoky' aroma, with an aroma threshold of 110 µg/L.
• 4-ethylcatechol: 'Horsey' aroma, with an aroma threshold of 774 µg/L in a neutral Australian red wine.

Wine taints:

• 2,4,6-trichloroanisole (TCA): Main compound for cork taint, with a distinct musty, mouldy aroma. Aroma threshold in Pinot Noir was 1.4 ng/L, but can be lower in dry white wines or higher in full-bodied reds. Consumer rejection threshold was 3.1 ng/L.
• 2,4,6-tribromoanisole (TBA): Similar musty, mouldy aroma to TCA, perceptible at 4 ng/L in wine.
• 2-Methoxy-3,5-dimethyl pyrazine (fungal must): Described as 'musty', 'foul drains', or 'sour dishcloths', with a threshold of 2.1 ng/L in a neutral white wine.
• Chlorophenols: 'Plastic', 'paint', 'medicinal', or 'phenolic' odours. 2,4-dichlorophenol has a detection threshold >896 ng/L, while 2,6-dichlorophenol is more potent at 32 ng/L.
• Geosmin: 'Earthy', 'musty', 'muddy' aroma with a sensory threshold of 25 ng/L.
• Smoke taint: Undesirable 'smoky', 'burnt', 'ashy', or 'medicinal' characters from vineyard exposure to smoke.

Understanding these faults is critical for assessing condition and making informed decisions about holding or selling wine. Ullage is one condition issue that can contribute to oxidation. Our guide on wine ullage levels explained covers it in detail.

How are wines scored in competitions?

International wine competitions, such as those sponsored by the OIV, follow strict standards for evaluation and scoring. A jury typically comprises 7 jurors, with a maximum of three nationals from the organizing country. Jurors evaluate samples anonymously in a quiet, well-lit, odour-free room held between 20 and 24 °C, as per the OIV standard. Jurors are provided with score sheets and descriptors, and they must remain silent during tasting to ensure absolute anonymity of samples.

Each sample's rating is the average of the scores from individual jurors. If a wine is marked "eliminated" due to a major defect by at least two jurors, it cannot receive an award from that jury. The OIV standard limits the total number of medals awarded to samples to 30% of the total samples presented. If this percentage is exceeded, samples with the lowest scores are eliminated.

Awards are classified into categories based on minimum point thresholds:

Award Level	Minimum Points
Grand Gold	92
Gold	85
Silver	82
Bronze	80

These awards may be further divided by sugar content, CO2 content, color, or vintage. The total awards in each group must not exceed 30% of the samples in that group, states the OIV standard.

How do external factors influence wine perception?

Beyond the intrinsic qualities of the wine, several external factors can significantly influence how a wine is perceived.

Blind Tasting and Bias: Scientific research has demonstrated the power of suggestion and the strong effects of expectancies in wine perception. When participants were falsely told a wine was expensive, they virtually always reported it tasting better. The same wine tasted worse to them when they were told it was inexpensive. Similarly, a white wine dyed red was described with red wine terms like "intense, spicy, supple, deep" by tasters who had previously described the undyed version as "fresh, dry, honeyed, lively." The 1976 Judgment of Paris is a famous example of how impartial judgment can lead to unexpected results. California wines bested French wines in that blind tasting.

Serving Temperature: The temperature at which a wine is served greatly affects its taste and smell. Lower temperatures emphasize acidity and tannins while muting aromatics. Higher temperatures minimize acidity and tannins while increasing aromatics. For example, light-bodied red wines like Beaujolais are best served lightly chilled at 10-12 °C (50-54 °F). Full-bodied red wines such as Cabernet Sauvignon are typically served at 15-18 °C (59-64 °F). The OIV standard for competitions recommends serving white and rosé wines at 10/12 °C and red wines at 15/18 °C.

Glassware: The shape of a wineglass can subtly impact the perception of wine, particularly its bouquet. The ideal shape is generally considered wider toward the bottom, with a narrower aperture at the top. Tulip and egg shapes are the usual examples. The INAO wine glass has been an official standard since 1970. It holds approximately 215 ml but is intended for a 50 ml pour. Its opening sits narrower than its convex part, which concentrates the bouquet.

These factors underscore the importance of controlled tasting environments, like those used in OIV-sponsored competitions, to minimize bias and ensure consistent evaluation.

What are common sensory descriptors for grape varieties?

Wine tasters use a wide range of descriptors to characterize grape varieties, drawing comparisons with non-grape flavors and aromas. These descriptors help communicate the typical characteristics of a wine.

Red Grape Variety	Common Sensory Descriptors
Cabernet Franc	tobacco, green bell pepper, raspberry, freshly mown grass
Cabernet Sauvignon	blackcurrants, eucalyptus, chocolate, tobacco
Gamay	pomegranate, strawberry
Grenache	smoky, pepper, raspberry
Malbec	violet, plums, tart red fruit, earthy minerality
Merlot	black cherry, plums, tomato
Mourvèdre	thyme, clove, cinnamon, black pepper, violet, blackberry
Nebbiolo	leather, tar, stewed prunes, chocolate, liquorice, roses, prunes
Petite Sirah (Durif)	earthy, black pepper, dark fruits
Petit Verdot	violets (later), pencil shavings
Pinot noir	raspberry, cherry, violets, "farmyard" (with age), truffles
Pinotage	bramble fruits, earthy, smoky
Sangiovese	herbs, black cherry, leathery, earthy
Syrah (Shiraz)	tobacco, black/white pepper, blackberry, smoke
Tempranillo	vanilla, strawberry, tobacco
Teroldego	spices, chocolate, red fruits
Zinfandel	black cherry, pepper, mixed spices, mint, anise