Blending wine from different vintages, different barrels, different grape varieties can be thought of as an easy task, but is there more to it than most enthusiasts believe? Is the task of blending wine an art form?
When a winemaker chooses wines from different barrels to blend with other barrels, he usually has in mind what characteristics each batch of barrels have. Also being able to predict what the effect of adding two or more rather different wines together is a skill. The most gifted blenders will already be thinking about the usefulness of certain components of blending while the grapes are still on the vine. Their are many reasons why winemakers blend wines from different grape varieties and different barrels. Winemakers could blend their wine to adjust alcohol content. This happens when the base wine has a lower or higher alcohol content than the desired blend. Winemakers also blend to adjust acidity. This happens when a batch of wine has lower or higher acidity TA than the desired blend.
Winemakers must be cautious when blending as it is very easy to destroy a good wine. Blending a good wine to improve a bad wine only makes more bad wine. However if a wine is deficient in colour, body, acidity, etc it can be improved by blending it with a wine strong in the characteristic that it is lacking. Bordeaux blends for example are made from Cabernet Sauvignon, Merlot, Petite Verdot, Carbernet Franc and Malbec; each grape varietal brings something different to the final blend. Cabernet provides the structure and balance, Petite Verdot adds depth in colour and tannins and Malbec can add fruit flavours. Determining the amount of each varietal is up to the winemaker.
Their are many other well known blends for example the Rhône blends Syrah, Grenache, Mouvèdre, Cinsault etc. Many white wine varietals can blend together nicely such as Sauvignon Blanc and Semillon. Of course many old world and new world countries keep to one varietal when making their wine, but usually what is not placed on the bottle is how these 'single' varietal wines have been blended with small amounts of other varietals.
Blending wine is a chance to make a wine transform into something more beautiful than from what it was at the beginning, but it is also a stage in the winemaking process, which could diminish the quality of the wine. It is up to the winemaker to understand all the characteristics of the vineyard, grape varieties involved and the different barrels. So as you can see, blending wine is no easy task, it is a skill which once perfected becomes an artform.