Last but not least, we will conclude this series with the best part of any wine tasting: the tasting itself, how does it taste?
Open a bottle, pour a little bit of wine in a glass, enjoy its colour and perfume (see previous articles). Now let's take a sip of wine and examine its quality.
The human tongue is limited to the primary tastes perceived by taste buds receptors (sourness, bitterness, saltiness, sweetness and savoriness.) 80% of the aromas detected in a glass of wine are actually olfactive.
Interestingly, those aromatic compounds are perceived differently depending on the wine solution. It is the combination of the aromas with the liquid's ingredients that give the wine the flavours that we enjoy so much. Wine is composed of water, alcohols, acids, residual sugars, and polyphenols like tannins. Let's have a closer look at each of these wine components.
- The first sip should tell you if the wine is served at the right temperature. Generally speaking, the lighter the wine, the chiller it should be served.
We recommend to serve most sparkling wines (Cremant, Champagne) around 6 - 8C, light bodied whites (Loire Valley) around 8 - 10C, Medium bodied whites (Burgundy, Bordeaux) around 10 - 12C, full bodied whites (Alsace, Rhone) around 12 - 14C. Similarly, enjoy light bodied reds around 12 - 14C (Loire Valley), medium bodied reds around 14 - 16C (Burgundy), full bodied reds around 16 - 18C (Bordeaux, Rhone Valley). 2 hours in a fridge (6C) for white and 1h for red should be enough or you can use an ice bucket between 15 to 30 mins if you can't wait to drink.
Beware that if the wine is served too cold (<6C), it will seem very thin, almost tasteless, with bitter tannins for reds, while if it is too warm (>20C), the wine will lose its balance and the alcohol and acidity will "jump out" of the glass.
- Acidity is a major component of wine. Imagine any kind of fruit (lemon, apple, cherry, blackcurrant...) without acidity, its taste would be heavy, unpalatable. Higher acidity also ensures that the wine will stay fresh and keep well on the long term, allowing the winemakers to use less preservatives. There are 3 major acids which are naturally present in grapes (tartaric, malic and citric) while others acids occurs during the course of winemaking (acetic, lactic, succinic), having direct influences on the color, balance and taste of wine. Most of them are fixed acids with the notable exception of acetic acid, which is volatile and can contribute to the wine fault known as "volatile acidity" (vinegar taint).
The measure of acidity in wine is known as “Titratable Acidity” (TA), which refers to the total amount of acids present in grams per litre (usually between 3.5 to 7g/L), while the strength of acidity is measured according to pH, a logarithmic scale with most wines having a pH between 3 and 4 (1 point lower pH = 10 times higher acidity). Given the same amount of total acidity, a wine will either taste sour and tart with a pH comprised between 2.5 - 3, crisp and bright (pH 3 - 3.5), fresh and smooth (pH 3.5 - 4) or flabby, oily, flat (pH 4 - 4.5).
When choosing a bottle of wine, keep in mind that cool climates wine regions (i.e. northern parts of France) usually have a longer growing season with overall less sunshine (1500 hours in Champagne) and lower temperature on average (11C in Champagne), than warm climates (2900 hours of sunshine with an average temperature of 14C in Provence). Hence, grapes growing in a cool climate region will have more acidity and less sugars (Champagne, Loire, Chablis...) and the wines there will generally taste fresh and elegant, while grapes growing in warm climates will have less acidity and more sugars, therefore their wines will usually be more round and powerful (Rhone, Languedoc, Provence).
- Sugars in grapes are at the heart of what makes winemaking possible. Glucose, along with fructose, is one of the primary sugars found in wine grapes. At the beginning of the ripening stage there is usually more glucose than fructose present in the grape, but as the vines consume glucose through the respiration, at harvest time, glucose and fructose are generally in equal amounts. Grapes that are over ripe, such as Alsace's late harvest wines, will have more fructose than glucose, which is ideal to produce dessert wine (fructose taste sweeter than glucose).
During the process of fermentation, sugars are broken down and converted by yeast into alcohol and carbon dioxide. The more sugar there is, the more alcohol there will be in the wine. The fermentation will continue until a specific level of alcohol is reached where the yeasts cannot survive any longer (around 15% alcohol). At this point, the fermentation stops and the sugar that has not been turned into alcohol, remains in the wine and is called residual sugar. A winemaker that chooses to halt fermentation (either by temperature control or the addition of brandy spirits in the process of fortification) will be left with a wine that is high in fructose and taste off dry or even sweet (ie Vin Doux Naturel).
Most of the wines consumed nowadays are dry. Even among the driest wines, it is rare to find wines with a level of sugar less than 1 g/L, due to the unfermentability of certain types of sugars, such as pentose. Still wine is considered dry up to 4 g/L, off dry between 4-18 g/L, medium dry between 18-50g/L. Any wine with over 50 g/L would be considered sweet, though many of the great sweet wines have levels of residual sugar much higher than this. For example, Sauternes is comprised between 100 - 150 g/L.
How sweet a wine will taste is also controlled by factors such as the acidity and alcohol levels, the amount of tannin present, and whether the wine is sparkling or not. Sugars and alcohol enhance a wine's sweetness; acids and tannins counteract it. A sweet wine can actually taste dry due to the high level of acidity. And a dry wine can taste sweet if it has a high level of alcohol.
Wine alcohol content is a main part of a wine body or mouthfeel. People refer to alcohol in wine through common descriptors, light body (11-12% ABV), medium body (13% ABV) or full body (14-15% ABV).
- Tannins play a major part in the flavors of red wine. Tannins are the flavonoids in wine that are leached out of the grape skins, stems and seeds during the maceration. The amount of phenols leached is known as extraction. These compounds contribute to the astringency, color and mouthfeel of the wine. In white wines the number of flavonoids is reduced due to the lesser contact with the skins (direct pressing), which is why red wines typically have more tannins than whites (typically 5 to 7 times more).
Wines (red and white) can also take on tannins from the oak if they are aged in barrels. The oak species, country of origin, age of the trees, size of the barrels, and whether the barrels are new or old, will also affect the type of tannins passed on to the wine.
Grape varieties like Gamay from Beaujolais, Pinot Noir from Burgundy, and Grenache in the Southern Rhone Valley have a thin skin, delicate ruby red color and soft tannins for immediate pleasure. On contrary, Cabernet Sauvignon from Bordeaux, Malbec and Tannat from South West and Syrah from Northern Rhone Valley, have a thick skin, with a dark robe, and are particularly tannic. Such wines mellow and improve with age with the tannic "backbone" helping the wine to survive for as long as 40 years in proper conditions.
Tannins impart a mouth-puckering astringency when the wine is young but "resolve" (through a chemical process called polymerization) into delicious and complex elements of "bottle bouquet" when the wine is cellared under appropriate temperature conditions, preferably in the range of a constant 11 to 13 °C.
In many regions such as in Bordeaux, tannic grapes like Cabernet Sauvignon are blended with lower-tannin grapes such as Merlot or Cabernet Franc, diluting the tannic characteristics and making them approachable at a younger age.
When a wine’s alcohol, acidity, residual sugar and tannins are well integrated, we will say that the structure is balanced, and the wine is deemed harmonious, the highest achievement a winemaker can aim for, which probably have led wines to receive so many laudatory praises throughout the course of History, like Ernest Hemingway, who once said “A person with increasing knowledge and sensory education may derive infinite enjoyment from wine."
We hope that you enjoyed reading this article and learn a thing or two about tasting wine, cheers!
(Credit images : Wine Folly / Guild Somm)