Tannins, a question of experience and intuition
When you drink a glass of red wine, you definitely talk about its tannins. I like to think that everybody has the capacity to stop for a moment, take a deep breath and feel what the wine has to offer. But where do the tannins come from and what justifies the number of qualifiers used to describe the texture in mouth; discreet, thin, chalky, fleshy, strong, astringent, silky, green, robust, etc.? How is the analysis of the tannins in a wine important when we talk about balance? I will try in the following text to demystify some of the mystery associated with this substance contained in wine, chocolate, and tea.
First of all, the tannins in the wine come mostly from the grapes (the skin, the seeds, the stems) and the barrels in which the wine will continue its maturation. Logically, during vinification, the more skins, seeds, and stems, the higher the tannin content in the wine. The grape variety used for the production also plays a major role in this matter. Grape varieties like; Malbec, Cabernet Sauvignon, Syrah and Nebbiolo will produce wines with higher tannin content. But, this is only one factor among many that influences the structure, texture, and body of a wine. Take the Cabernet Sauvignon, for example. This variety is vinified in different regions of the world through the Bordelais in France, Margaret River in Australia and Napa Valley in the United States. Although they are all from the same grape, the tannins in these wines will also be characterized by their place of origin (terroir), the techniques used during the vinification, and the type of barrel used for maturation.
During the maturing phase of the grapes, the date of the harvest must be carefully established according to the phenolic maturation: the moment when the phenolic compounds of the grapes (tannins and anthocyanins) reach their optimal concentration. This date is of great importance since an early harvest could cause astringent tannins, whereas if done too late, the tannins may lack structure. The longer you wait during the ripening period, the more sugar increases in the fruit, but the acidity decreases. The result will be a wine with a high alcohol content that lacks acidity and balance in the end. Any winemaker who wants to develop a quality wine has to taste the evolution of the grapes every day. Thus, he will be able to establish the optimal harvest date for a vinification with grapes at ideal maturity and the desired amount of tannins.
In the winery, the winemaking techniques are endless, and it is up to the winemaker to establish his own methods: depending on what type of wine he desires. The most crucial step in tannin extraction occurs at the fermentation stage. During this phase, at a controlled temperature (between 20 and 32 ° C), the winemaker must decide the maceration time of the grape skin with its juice (can vary from 8 days to 3 weeks). He must also determine the number of pigeages and remontages, operations that promote the extraction of tannins and aromas in the wine. The quality of the press used is also really important for this matter. The goal is to press the grapes as gently as possible to release the juice without crushing the seeds that release unwanted aromas. The question of using grapes destemmed or not at the beginning of the fermentation process also arises. Many winemakers are experimenting, while the trend of fermentation with whole bunches of grapes has been in vogue for the last decade. It is not uncommon to see the percentages of whole clusters allocated to fermentation on the description of the back label. The addition of supplements is also possible (tannin powder and wood chips) to increase the tannin content, but the texture in mouth will never be as refined as when the natural tannins of the grapes are incorporated. A general rule to the different wines made all around the world is that the aging of wine in oak barrels makes it possible to transmit substances to the wine (tannins and aromatic compounds). Oakwood has the property of gradually incorporating oxygen into the wine. This very slow oxidation process has the effect of stabilizing the wine, bringing structure and color. But, the contribution of wood is not automatically beneficial to the wine, a mediocre wine at the base will not benefit from aging in oak barrels.
Finally, at a tasting, the types of tannins in a wine will greatly influence its balance. If the tannins are ripe and spread harmoniously throughout the mouth, feeling more towards the back rather than in the front of the palate, we can conclude that they are pleasant. If a nice acidity and a good level of alcohol support and accompany these tannins, it will be said of the wine that it has balance with a potential of guard. Whether you like them tighter, structured and stronger or rounder, coated and greasy: there are types of tannins for all tastes and occasions. Personally, I do not get bored of what tannins have to tell when I blindly taste a glass of red wine: what grape variety is it made from, where does it come from, was it a hot or fresh… Here is a complex red wine: juicy, with excellent aging potential, structured, and elegant tannins. To decant imperatively before serving. Great tasting!