Wine lessons

Classification of wine

Wine is truly a complex beverage in many ways. Its production method, the blend of different grape varieties, the richness in scents and flavours that develop in a glass, the complexity of factors influencing the development of the wine characteristics… and many other reasons make the wine a unique drink and concurrently explain our fascination with wine.

It is not a simple task to classify wines as there are various classifications. For instance, depending on whether the bottle contains trapped carbon dioxide, wines can be classified in two categories: still wines and sparkling wines. Champagne is the most famous example of a sparkling wine.

The basic classification of wine is by colour. All wines are made from grape juice, but depending on the grape variety and the duration of the contact between juice and skins after grapes have been crushed, wines can be categorized into:

  • White wines – made from white varieties of wine grapes
  • Red wines – made from red varieties of wine grapes
  • Rosé wines – made from red varieties of wine grapes, but the production process involves a limited contact between the juice and grape skins

During fermentation, the naturally occurring sugar in the juice converts into alcohol. If the entire amount of sugar is converted to alcohol during fermentation, this process yields a dry wine. The fermentation process, however, can be stopped and a larger or smaller amount of natural sugar can be retained in the wine. Depending on the amount of residual sugar, wines can be categorized into semi-dry, semi-sweet and sweet wines.

Furthermore, there are dessert wines. These wines are usually made from late harvest grapes when the grape berries bear a resemblance to raisins and are abundant in sugar. In certain wine regions, the harvest is delayed until grape berries in the vineyard have frozen. At this point, the sugar amount is so high that it is impossible for it to fully ferment into alcohol, and this method results in a wine with low alcohol percentage and a sweet taste. There are also fortified wines. These are sweet wines that have had their fermentation process stopped by the addition of a spirit. Popular examples of fortified wines include Sherry, Port, Madeira, Marsala, Vermouth and Bermet.

Moreover, wines can be classified by their origin (geographically controlled or not), by region, varieties, harvest … As mentioned above, it is quite difficult to thoroughly explore this subject.

Wine tasting

Wine tasting is a sensory examination and evaluation of the wine. It requires the use of the senses of sight, smell and taste. Professional wine tasters use formal terminology to describe the quality and characteristics of the wine, but a more informal, recreational wine tasting can also be performed whereby we can express our personal opinion and assessment of a certain wine.

Wine tasting tips:

Step 1 – Sense of sight

When tasting a wine, attention should be first paid to its colour by placing the glass against a white background. The wine should have an ideal clarity and by swirling the glass we can see streaks on the inner sides of the glass called ‘legs’ or ‘tears’. The velocity of their descent down the sides of the glass indicates the amounts of alcohol and grape extract in the wine. The colour of white wines varies from greenish yellow to golden yellow, whereas the colour of red wines can vary from red purple to ruby red colour. The colour of the wine is bestowed by the variety, vinification method and the region of origin and varies depending on the wine’s age. Rosé wines can have a lighter or darker pink colour or a pinkish colour with orange tones.

Step 2 – Sense of smell

Before smelling the wine, the glass should be swirled, allowing the aromas to release. The different scents perceived in the wine are called bouquet (word of French origin) and they foreshadow the wine characteristics. Each grape variety has its own distinctive aromas. They are called primary aromas since they impart from the compounds found in the grape itself. Secondary aromas are those derived from fermentation, whereas tertiary aromas are those that develop through bottled aging and are the most difficult to perceive. Aromas that can be noticed when smelling a wine are categorized in several groups: fruity, floral, spicy, vegetal, earthy, woody, chemical, microbiological, nutty, caramel and refreshing. If the wine is fermented or aged in oak barrels (barriques) during the vinification process, distinctive aromas of vanilla, overcooked bread, coffee, smoke and dark chocolate will be released. However, it is also possible that the wine would have an unpleasant smell of vinegar, mould, wet towel, moist etc. These odours are undesirable and indicate a problem with the wine.

Step 3 – Sense of taste

In order to perceive its flavour and weight, the wine should coat the gums and tongue. This is the method to determine whether the wine has a light, medium or full body. Also, the sense of taste helps us perceive the wine’s sweetness, sourness and bitterness. If you slurp some air through puckered lips, you can feel its flavour with an even greater intensity. Additionally, when tasting red wine you will discover tannin, a naturally occurring compound found in the skin, seeds and stalks of the grapes. In younger wines, the tannin has a sharper and more intense taste, but over time it ripens and softens. You can also perceive so called ‘green’ tannins, which appear in wines made from unripe grapes, which is an undesirable characteristic in wines. Savouring the wine enables you to evaluate the duration of the aftertaste once it is swallowed. The longer the aftertaste lingers, the finer the quality of the wine. As a general rule, fine wines exhibit faultless harmony between flavours, aromas, acidity, alcohol and tannins.

It is a well-known fact that higher quality wines have a more complex array of flavours and aromas. If oenologists succeed in giving the wine a special character and make its flavour unique, a wine of such calibre will surely capture the hearts of even the most fastidious wine lovers.

Wine serving

Several key factors need to be considered. Serving wine properly is important since enjoyment in the wine is greater when served correctly.

Temperature – The correct serving temperature will undoubtedly improve the wine’s taste and scent. Over-chilled wines lose their aromas and flavour, whereas under-chilled wines have an unpleasant taste, primarily due to the excessive alcohol evaporation which overpowers all other aromas and modifies the characteristics of the wine.

White wines are always served chilled, whereas red wines are served at room temperature, having in mind that the temperature in the room should not exceed 20°C. Also the sweeter the wine, the colder it should be when served.

It is best to follow these instructions:

  • Serve red wine at temperature of 16°C to 18°C
  • Serve white wine at temperature of 12°C to 14°C
  • Serve rosé wine at temperature of 10°C to 12°C
  • Serve sparkling wines at temperature of 8°C to 10°C

Before serving, refrigerate the wine for about 20 minutes or place it in an ice bucket to lower its temperature to the desired serving temperature.

Opening – Wine should be opened with a special opener (corkscrew). First remove the capsule from the top of the bottle by cutting it and making sure it does not get in contact with the wine when it is poured. Put the worm of the corkscrew in the centre of the cork and twist the corkscrew clockwise, making sure that the lower part of the cork doesn’t disintegrate, since that can lead to cork bits falling down in the wine. Finally, draw the cork from the bottleneck.

Decantation – Decantation is the process of pouring the wine from its original bottle into another vessel called decanter. This technique is normally used for older wines laden with sediments which have deposited overtime, in order to separate the wine from these sediments. Decantation is also useful for wines that have no lees. By decanting a younger wine, the liquid gets in contact with air (aeration) which speeds up the development of the bouquet and refines the taste of the wine.

Decanting younger wines is much easier. All you need to do is pour the wine into a decanter and leave it for 15 minutes before serving. Decanting older wines is more difficult since the sediments need to be carefully separated from the liquid. When decanting an older wine, first place the bottle in an upright position or in a decanting basket at a 45° angle for at least 12 hours, so that the sediments can deposit at the bottom of the bottle. Once opened, place the bottleneck in the direction of the decanter and place a light source underneath (a lit candle, for example) so that the sediments can be more easily detected. Then pour the wine slowly and evenly into the decanter until the sediments from the wine reach the bottleneck. Red and white wines should be left in a decanter for half an hour and 20 minutes respectively, before serving.

Glassware – Wine should be served in special stemware made of thin, pure glass. Engraved or coloured glassware should be avoided since it prevents us from seeing the wine colour clearly. Red wine is served in wide tulip-shaped glasses, whereas white wine is served in glasses with a slightly narrower opening. Sparkling wines are served in narrow and tall glasses allowing the bubbles to form.

When pouring wine, make sure not to overfill the glass. Ideally, a glass should never be filled more than halfway, as there should be enough room to swirl the glass and thereby release and intensify the aromas.

Wine storage

Wine is stored in underground cellars since they provide propitious conditions. It is best to store wines in a calm, dark and cold room with sufficient levels of humidity (70-75%). Bottles are placed horizontally, as the cork must be constantly moist in order to prevent it from drying out and in order to avoid oxygen penetration in the bottle. Sparkling wines and screw-capped wines can be kept upright since there is no danger of oxygen penetration and wine oxidation.

Wine should not be kept near heat and light sources as well as next to vibrating machines. It is best to maintain a constant temperature in the room, as temperature oscillations can harm the wine. High temperatures and strong light can also have adverse effects as they can cause oxidation of the wine.

If you don’t own an underground room suitable for wine storage, try to find a dark, enclosed space with a constant temperature, far from vibrating appliances. Lately, a growing number of wine lovers decide to keep their wines in special wine coolers that provide ideal conditions for home wine storage.