If you are a wine connoisseur or just a wine lover, you have certainly heard of tannins. Everyone who drinks wine has had some experience with tannin.
Tannins can be a confusing subject. Perhaps, you have lots of experience with tannins but you are not really sure what tannins are, or what their role is in wine. This isn’t surprising. How tannins form, or their role in wine, is not perfectly understood. Research continues on the subject. However, most wine lovers agree that tannin adds complexity to wine by adding another dimension – one of texture. This texture in wine is sometimes referred to as structure (a term that indicates the role of tannin in wine).
Tannins actually have more to do with our sense of touch than with taste. Tannins create a drying sensation in the mouth. If you have ever tried really strong black tea, then you are familiar with the drying, mouth-puckering sensation of tannins. Besides wine and black tea, you will also find tannins in coffee, nuts, seeds, red meat, chocolate (especially dark chocolate), beans, fruit skins and spices.
Some wine enthusiasts find it hard to distinguish between tannins and acidity in wine. It’s true that both create similar initial sensations in the mouth. However, there is one major difference between the two: The acids in wine that are responsible for acidity (tartaric acid, malic acid, citric acid) cause you to salivate, while tannin (though, technically, an acid) leaves your mouth dry. So, it could be said that they start out similar but finish very differently.
Tannin is a biomolecule belonging to a family of compounds known as phenols. There are two chemical classifications of these polyphenols found in wine: Hydrolysable (water-soluble) tannins and condensed tannins. Primarily, hydrolysable tannins, in wine, come from the grapes, while condensed tannins come mostly from oak barrels.
Tannins in wine come mainly from the skins of grapes with some coming from seeds and stems. Many people think that tannins are what give red wine its pigment. But, tannins are only one polyphenol found in wine and not the one primarily responsible for colour. The compound primarily responsible for giving red wine its ‘red’ is not tannin but another polyphenol called anthocyanin.
How much tannin a wine has depends on several factors including: ripeness of grapes, variety of grape and the wine-making processes utilized.
As grapes ripen, their tannins soften. Under-ripe grapes are extremely astringent and bitter. This acts as a natural defence against birds and insects. The grapes then have the chance to ripen on the vine. Some grape varieties have more tannin than others. Red varieties usually have more than white, and. Also, grapes with grapes with thicker skins have more tannin than their counterpart.
There are two factors in wine- making that affect tannin levels in wine. One is the method used to press the grapes. The harder the grapes are pressed, the more tannin the grape juice will yield. The other is the amount of time the winemaker allows the juice to remain in contact with the grape skins and seeds after pressing.
Tannins are one of the components that make wine age-worthy, possibly the most important component. This is because they are an excellent natural preservative. Of course, tannins alone don’t make a wine age-worthy. Alcohol and sugar are also natural preservatives. Furthermore, one of primary requirements for a wine to stand the test of time is balance. This means that all the different factors (including tannin) are proportional to one another. This includes: flavour (especially fruitiness), acidity, sugar levels, alcohol levels and tannin. As Robert Parker observed: “Balanced wines are symmetrical and tend to age gracefully.” Wines without detectable tannins tend not to age well and are usually intended to be consumed when young, (typically, within 5 years).
High tannin wines include red wine from Bordeaux, as well as Barolo, Barbaresco, Port and Chianti, to name a few. Grape varieties which usually produce wines high in tannin include Tannat (a name which may be derived from tannin), Nebbiolo, Cabernet Sauvignon, Merlot and Malbec. Of course, this is just a short list. There are many other high-tannin grape varieties and many other high-tannin wines.
White and rose´wines are usually quite low in tannin. But red wines can be low in tannin as well. An example of red wines that are low in tannin would be the red wines of the Burgundy region or wines from California and Australia. Low tannin red grape varieties include: Gamay, Pinot Noir, Dolcetto and Grenache.
Some people love high-tannin wines. Others really don’t care for tannin. A link has been observed between people who like high-tannin wines and people who like other high-tannin beverages and foods. As an example, people who come are from places where a lot of tea is consumed, tend to favour high-tannin wines. Likewise, appreciation for tannin can increase with exposure. People new to wine tend to shy away from high-tannin wines in favour of softer, more fruit-driven wines. Over time, people often develop a fondness for tannin in their wine.