Wine Judging Using the UC Davis 20 Point System
by Lum Eisenman



Most wines are judged in consumer oriented competitions. The results of these competitions are widely publicized, and the judges are well-known members of the wine industry. Many wineries submit wines because a gold medal won at these competitions can double or triple wine sales.
Consumer wine competitions are the most widespread. However, wines are judged for several reasons, and sometimes wines are judged and the results are never made available to the public. For example, wines are judged and scored to facilitate the sale of bulk wines between commercial wineries. The Davis 20-point system was originally developed primarily for the wine industry to help expedite bulk-wine transfers between wineries. In addition, a few wine competitions, like the Orange County Home Wine Competition, are held primarily to provide encouragement and feedback to aspiring winemakers. In these competitions, the winemaker often receives a copy of the judge's score-sheet for each wine submitted. Novice winemakers get unbiased information about their wines and benefit greatly from participating in these kinds of wine competitions.


Since judging wines is so subjective, the only credible way of determining wine quality is to taste wines blind. Here, the term blind implies the judges never see the wine labels, and the wine producer is unknown. Many large wine competitions use a double blind system. Here, the wine bottles are covered and given an identifying number by competition officials. On judging day, the wines are delivered to the steward's room that is separate from the judging room. Stewards then pour the wines into numbered glasses and deliver the glasses to the judges. In these competitions, neither the stewards nor the judges know the identity of the wines, and the judges only see glasses of wine.
Popular wine publications rate dozens new wines in each issue. Many publications do these ratings blind and their wine ratings are legitimate. Unfortunately, some publications do not score their wines blind, so these ratings are always suspect. A strong correlation was found between wine scores and square inches of advertisement in a popular publication just a few years ago. The only credible way of determining wine quality is when the judges taste the wines blind.
Wine is seen before it is tasted, so our first impression of any wine is a visual one. Wine is expected to be brilliantly clear and it must have an appropriate color. Consumers are always disappointed when a wine does not meet these visual expectations. Even the most zealous wine patron balks at turbid, dirty-looking wines. Judges at home-wine competitions occasionally face this problem, and considerable courage is needed to taste a particularly ugly looking wine.
The olfactory sensors are located in the upper portion of the nasal cavities. Relatively little air gets to these sensors during normal breathing, so wine must be sniffed to force wine odors up into the sensors. Two terms are used to describe the way wine odors. Aroma is used to describe smells that originate from the grapes. Thus, smells from a particular variety of grapes are called aroma. Bouquet is used to describe the smells originating from the winemaking process, and the odors produced by barrel aging are also called bouquet.

Taste sensors are located on various parts of the tongue. Only four basic tastes can be distinguished by these sensors: sweet, sour, salty and biter. Sweet tastes are pleasant, but sour, salty and biter tastes alone are usually unpleasant unless they are balanced by sweet tastes, and this balance is very important to wine quality. In wine, alcohol and any residual sugar provide sweetness. The several organic acids present produce the sour taste. Potassium, sodium, calcium and other salts present, produces the salt taste. Phenolic materials often called tannin produce the biter taste.
Wine flavor is often defined as odor sensation of wine in the mouth, together with the four basic taste sensations. So, the nose is most important for evaluating wine flavor and quality. The old saying "I have a cold and I can't taste anything" is particularly true when tasting wine.


Tip Glass: Most judges believe the color and clarity of wines are best examined by holding the wine over a white background and tipping the glass away from the observer. A wedge of wine is produced allowing the observer to view the optical characteristics through a different thickness of wine. Even dark wines show a transparent edge when the thickness approaches zero near the glass.
Swirl Glass: Odors travel from the glass to the observer's nose as vapors. Swirling causes the wine to climb up the sides of the glass, and a larger wine surface is exposed to the air. More wine evaporates from the larger surface, and more vapors are available to the nose.
Chew the Wine: Odors travel from the mouth up into the nasal cavity as vapors, and large surface areas produce more vapors. Judges take a large dollop of wine and coat the insides of their mouth by chewing the wine. The large surface of exposed wine produces more intense odors.
Reverse Whistle: Here is an effective tasting trick. Take a medium size dollop of wine. Move the wine to the front of your mouth and keep it on top of your tongue. Pucker your lips as if you are going to whistle, but do not blow out. Instead, tip your head down, and draw air into your mouth allowing the air to pass through the wine.
Spitting: Most judges don't swallow the wine. Judges that spit out the wine are usually asked to judge the following year. Judges that don't spit are seldom asked to judge again. Experienced judges can spit effectively into almost any kind of container. Most inexperienced judges have trouble keeping dribbles of wine off their cloths. Spit into a foam coffee cup is relatively easy.


Wines are judged by how they look, smell and taste. However, the way wines should look, smell and taste depends on the type of wine being judged. A light, White Muscat wine looks, smells and tastes differently than a heavy, red Zinfandel wine. Trying to compare the qualities of a White Muscat wine to a red Zinfandel is difficult. This is why most wine competitions divide the wines into different classes or groups. Smaller wine competitions often separate wines into a few general categories such as red table wines, white table wines, dessert wines, sparkling wines, etc. But, larger wine competitions separate the entries by grape variety to make judging easier and less subjective.

Varietal wines are judged by comparing their characteristics against a perfect or "standard" wine of the same variety. The characteristics of these standard varietal wines are defined by popular consensus. Wine consumers are somewhat fickle and the standards for varietal wines can and do change over long periods. Big, heavy Zinfandel wines were very popular thirty years ago. Normal, light-bodied Zinfandel wines won very few awards then. But, this heavy style of wine does not go well with foods, and now, the perfect or standard Zinfandel is a much lighter wine. Consequently, judges must be completely familiar with the types of wine they are judging.


Low Acidity: Wines containing too little acid taste flat or bland or insipid. Big, red wines contain more phenolic materials, and phenolic materials together with acid cause harshness. So, big red wines often contain less acid to balance their higher phenolic content.
High Acidity: Wine made from grapes grown in cold climates often contain too much acid, and wines containing too much acid taste sharp and excessively tart. (The wine industry does not use the word "sour" to describe high acid. Sour is used to describe vinegary wines). Table wines containing small amounts of residual sugar often contain extra acid to balance the sugar.
Acetic Acid (volatile acid): Microbes can convert alcohol into acetic acid, and acidic acid smells like vinegar. Acetic acid can react with ethyl alcohol and produce ethyl acetate, and ethyl acetate smells like "finger nail polish" remover. All wines contain some acetic acid and ethyl acetate, and in small quantities, both materials can make a positive contribution to the nose of the wine. But, too much acetic acid gives wine a vinegar character and produces a hot, burning aftertaste, too much ethyl acetate makes wine smell like finger nail polish remover.
Astringent: Red wine grapes have clear, colorless juice. The red pigment is in the grape skins. Red wines are made by crushing the grapes and then fermenting the juice, pulp, seeds and skins together. Besides the color, tannin is extracted from the skins and seeds. Tannin produces astringency and astringency produces harsh, rough wines. Astringency decreases as wines age. Some young red wines are often too astringent, and some discretion is needed here. On the other hand, white and blush wines should never exhibit significant astringency.
High Alcohol: The alcohol content of most table wines is about 12%. Some light, white wines such as White Muscat only contain 8 or 9 percent alcohol. These wines are so delicate they would be out of balance with more alcohol. On the other hand, the alcohol content of some big, late harvest red wines contains 14 or 15%, and these wines remain balanced. Too much alcohol in a wine produces a hot or sharp character in both odor and taste.
Excess Oak: Most high quality red wines and some white wines are aged in oak casks, and oak aging can add several desirable qualities to wine. Oak can produce a faint vanilla character that enhances wine fragrance and contributes to wine complexity, but too much oak can spoil a fine wine. Excess oak can produce a "woody" character in wine, and excessive amounts of vanilla can obscure aroma and bouquet.
Oxidized: When wine oxidizes, some alcohol is converted into a material called acetaldehyde. Acetaldehyde is a volatile liquid with a nut-like odor. Sherry wines contain much acetaldehyde, and the acetaldehyde gives Sherry its distinctive character. Although desirable in Sherry, even small amounts of oxidation are considered a fault in table wines.
Excess Sulfur Dioxide (SO2): Sulfur dioxide is added to wines to help protect the wine from microbes and excessive oxidation. In small amounts, SO2 is undetectable in the nose or taste of wine, but too much sulfur dioxide produces a pungent, acrid odor. The smell of a burning match is produced when sulfur in the match reacts with oxygen in the air and produces sulfur dioxide.
Hydrogen Sulfide (H2S): Hydrogen sulfide produces the familiar "rotten egg" odor. Small amounts of H2S often produce dirty, off or skunk-like odors. Tiny amounts may not produce any

odor but it can kill the fruity nose of a wine. Unless removed promptly, H2S can turn into mercaptan, and mercaptan smells like natural gas, sewer or rotten cabbage.


Judging wine quality is not easy. Substantial amounts of practice (someone has to do it) and a systematic approach is required. Several wine judging methods have been developed, but the 20-point system, developed at the University of California Davis, is the method used by most professional winemakers and tasters. This system is easily learned, and it provides a practical and convenient wine evaluation tool. The 20-point system uses ten descriptive factors to evaluate wine quality. Each of these quality factors is discussed below.

1. CLARITY / APPEARANCE: Wine is seen before it is tasted, so our first impression of wine is a visual one. Today, properly made wines are expected to be brilliantly clear, and consumers are always disappointed when a wine does not meet these visual expectations. Even the most zealous wine advocate shies away from turbid, dirty-looking wines, so appearance is always an important wine quality factor.
Several common conditions can cause cloudy wine. Clarity is the term judges use to describe the absence of suspended materials in wine. Suspended bacteria and yeast cells cause a hazy-white appearance. Similar milky-white hazes are caused by excessive amounts of iron. Excess copper often causes a reddish-brown haze. Tiny suspended crystals of potassium bitartrate can produce a dense, milky appearance in white wines.
Brilliant wines are clear and have a distinct sparkle (2). Bright-clear wines look like clean glass (1.5). Translucent wines have a dull appearance and may have a hint of haze (1.0). Cloudy wines exhibit an easily recognized haze (0.0).

2. COLOR: The hue, and how much color, constitutes another important wine quality factor. But, the human eye often has trouble distinguishing the hue in dark red wines. Hazy red wines often look somewhat darker in color, but wine clarity should NOT influence the score a judge gives for color. Color should always be typical for the type and age of the wine being judged.
Appropriate colors for white wines range from light straw to dark amber. Sometimes white table wines, such as Sauvignon Blanc, are a light straw color with a slight greenish tint. Brown tones may be appropriate for some types of white dessert wines, but brown shades are undesirable for white table wines. Colors for blush and rose wines range from light pink to light red. Brown shades are never appropriate for these wines, and orange tints are undesirable. Red wine colors range from light red to dark, almost opaque red. Purple/violet shades are prevalent in young red wines. Brick or brownish shades may be appropriate for older red wines. In general, ready to drink, red table wines show neither purple/violet nor brown colors. Brown or tawny colors are often appropriate for older, red dessert wines.
When the color of a wine is typical for type and age, the score is (2.0). A nearly correct color receives a score of (1.5). When the color is slightly off, the score is (1.0). When wine color is distinctly off, the score is (0.0).

3. AROMA / BOUQUET: Wine odors are complex and made up of many different components. To simplify describing wine odors, winemakers divide normal wine odors into two district components. One of these components is "aroma," and aromas refer to the odors in the wine imparted by the varietal characteristics of the grapes. The aroma characteristics of any wine are present in fresh juice before fermentation is started. For example, Muscat Blanc wine has a distinctive smell and most of this odor comes directly from the Muscat grapes used to make the wine. The best varietal wines exhibit easily detectable and discernable varietal aromas. Wine "bouquet" is the term used to describe the odors produced by the winemaking process. Wine bouquet is generated by fermentation byproducts, oak barrels, controlled wine oxidation, bottle aging, etc. The term "bottle bouquet" is used to describe the special odors that develop when some wines are aged in the bottle for several months. Bottle bouquet contributes to wine complexity.
Undesirable wine odors are occasionally encountered. These off-odors result from accidents or poor winemaking techniques. Sulfur dioxide, hydrogen sulfide, oxidized, raisin, green, mousiness, bacterial, rubber, moldy, etc. are a few of the off-odors encountered in wine.
The nose of a wine is composed of aroma, bouquet and any off-odors. If the nose is correct and has distinct varietal characteristics, the score is (4.0). Wines with a fruity nose are scored (3.0). Wines having a clean nose are scored (2.0). Wines with a fleeting or underdeveloped nose are scored (1.0). Wines with defective or off noses are scored (0.0).

4. TOTAL ACIDITY: Wines taste balanced when the total acid, alcohol and body are in the correct proportions. Wines low in total acidity often taste flat, insipid and uninteresting. Wines with excessive amounts of total acid taste sharp, under-ripe and unbalanced.
Wines with good balance and appropriate for the type are scored (2.0). Wines with slightly low or slightly high acid are scored (1.0). Flabby or overly tart wines are scored (0.0).

5. SWEETNESS: Normal table wines are either dry or off dry. Dry table wines do not have a significantly sweet taste. Many table wines are finished with 0.5 to 0.74 % residual sugar. These small amounts of sugar can enhance the mouth feel but not produce perceptibly sweet tastes. Off dry table wines such as Riesling have a slightly sweet taste, but an appropriately high acid content balances the sweetness. Aperitif, sparkling and dessert wines contain large amounts of residual sugar, and they are expected to taste sweet. Consequently, some wines contain too much sugar and some wines contain too little sugar. A sweetness that provides a good balanced wine and one appropriate for the wine type is the desired condition.
If the sweetness is appropriate and balanced, the wine is scored (1.0). If the wine is sweet edged (slightly too sweet) or not quite sweet enough, the wine is scored (0.5). If the wine is cloying, syrupy or lacking, it is scored (0.0).

6. BODY / TEXTURE: The body of a wine is a difficult concept to describe. Body is a way of describing the way wine feels in the mouth. A mouthful of milk feels differently than a mouth full of water. The milk feels heavier and thicker than water. The same concept applies to wine. A full-bodied wine feels heavy and viscous in the mouth, and the drinker is inclined to chew the wine. Dark red table wines are more likely to be full-bodied than white table wines, and the body should be appropriate for the wine type.
If the body of a wine is appropriate, the wine is scored (2.0). If the body of a wine is nearly correct, the wine is scored (1.5). If the body of a wine is slightly thin or heavy, the wine is scored (1.0). If the body of a wine is empty, thin or clumsy, the wine is scored (0.0).

7. TASTE / FLAVOR: Wines have a tremendous range of tastes and flavors, and the flavor changes as the wine ages and matures. This wine quality factor addresses how well the various flavors interact with each other. The flavors should be typical for the type of wine, and the wine should be smooth and balanced In other words, Sauvignon Blanc wines should taste like Sauvignon Blanc, not like Riesling.

If the flavor is complex, the wine is scored (2.0). If the flavor is fruity, the wine is scored (1.5). If the flavor is agreeable, the wine is scored (1.0). If the flavor is lacking, the wine is scored (0.0).

8. BITTERNESS: In general, bitterness is undesirable in wines because bitterness contributes to harshness. Most wines should be well balanced with no discernable bitterness. However, some grape varieties, such as Muscat, often exhibit slight amounts of bitterness, and skillful winemaking is needed to minimize this inherent bitterness. In general, these wines should not be downgraded because of this varietal characteristic unless the wine is unbalanced and the bitterness detracts from the wine.
If the wine is balanced, the score is (1.0). If the wine is citric or slightly bitter, the score is (0.5). If the wine is bitter, the score is (0.0).

9. FINISH/ASTRINGENCY: Excess tannin in wine produces a dry, puckering sensation in the mouth, and it gives the teeth a coated feeling. Astringency is the term used to describe these sensations. White wines contain less tannin than red wines, and in general, white wines should not exhibit much astringency. Young red wines often contain excess tannin, and they may exhibit too much astringency. However, astringency decreases as red wines age, and properly aged red wines become smooth and round. Since astringency changes as wines age, some judgement must be exercised when tasting young red wines.
If the finish of the wine is appropriate for age, the score is (1.0). If the finish is nearly correct, the score is (0.5). If the finish is astringent or harsh, the score is (0.0).

10. GENERAL QUALITY: Many judges use this factor to fudge their scores one way or another. Some wines may not look very good but taste great. Other wines may score well on all the above factors but may not taste quite up to par. All of the above factors contribute to the general quality of a wine, and drinking the wine should be a pleasurable experience.
Noble, etc. tasting wines are scored (4.0). Charming tasting wines are scored (3.0). Characteristic tasting wines are scored (2.0). Wines with no exceptional features are scored (0.0).