Wine is a natural product obtained by fermentation of grapes. It is very special in the sense that the final result depends on many factors like the variety of the grapes, the location of the vineyard but most important on the care and love of the vine grower as well as the wine maker.
The colour of wine depends on the variety, the composition, the stage of maturity and the way of vinification and conservation as well as the location of the vineyard (altitude, seaside etc).
The aroma of wine is difficult to describe so the taster characterises it according to the intensity, the volume, the quality and any specific characteristics.
The taste of wine mainly depends on its chemical composition and is the result of the equilibrium between its components. Wine can taste sour, bitter, salty or sweet or any combination of these. When we taste wine we seek the sweetness, the body, the balance, the texture, the aroma, the structure, the aftertaste.
The components of wine are derived from the raw material (grapes) and the wine making process. The main component is water. The next major constituent is alcohol in a proportion which can vary between 9 and 18 percent but is usually between 11 and 13 percent. Alcohol is a result of the fermentation of the sugars of the grape juice. The alcohol in wine confers the texture and the sweetness of the wine.
The sugars, mainly glucose and fructose are responsible for the sweetness of the wine. The acids, mainly tartaric acid and malic acid are responsible for the acidity of wine. The polyphenols and especially tannins, are responsible for the bitter and the sour taste of wine. Wine is composed of a vast array of complex and delicate molecules. And that explains the wide variety of wines available for us to enjoy.