The Sommelier's Tips

How to tell if a wine is tannic ?

860 Views Posted on: 2024-06-12
 

RECOGNIZING AND ANALYZING TANNINS

What do wine and tea have in common? Tannins! (or "tanins"; both spellings are accepted). Indeed, tannins are molecules found in many plant species. They are extracted through prolonged infusion and interact with saliva, creating that rough feeling on the tongue that we know so well. In tea, they are detected when the leaves are left in hot water for too long. The beverage then becomes darker and more astringent. But when it comes to wine, how can you tell if a wine is tannic? Why are only red wines considered tannic? Does this mean that grape berries are solely responsible for the tannin content?

What are tannins, and where do they come from?

Tannins are plant substances that dissolve in liquids and have the property of concentrating proteins, thus creating the astringency of a beverage.

In wine, tannins can come from any plant substance in contact during winemaking. This obviously includes the grape itself, but also barrels, if the wine is aged in casks. The primary source remains the grape skin. The thickness of the skin varies with the grape varieties and will naturally contain tannins in varying amounts depending on the grape variety. For example, a Gamay will be less tannic than a Grenache. Tannins are also found in the grape seeds and the stems, which are sometimes left in maceration.

Thus, only red wines, which get their color from maceration with the skin, are tannic, while white wines are not.

Wood, being a plant substance as well, will interact with the must and release its tannins. This happens when fermentation occurs in wooden tanks or when the wine is aged in oak barrels. The younger the wood, the more it will contribute additional tannins to the wine.

The tannic quality of a wine is therefore a blend of natural origin and winemaking expertise, including the grape variety used, the maceration duration, and the choice of wood.

What roles do tannins play in wine?

Tannins play a key role in the color and mouthfeel of red wines. Just as they make tea more or less opaque, they are responsible for the color of red wine. The more tannins present, the deeper and darker the wine's color will be.

They also contribute to the wine's body and length. The greater the tannin presence, the more the wine is considered to have powerful or hard tannins. Conversely, a lower tannin content means the wine has softer tannins. Tannins also affect the wine's length on the palate.

During tasting, it’s easy to notice that some tannins are persistent and linger in the mouth, while others are quickly washed away by saliva. This distinction helps differentiate fine (quickly fading) tannins from robust, persistent tannins. For example, a Malbec and a Cabernet Sauvignon, both high in tannins, will offer a completely different mouthfeel.

Lastly, tannins play a role in a wine's aging process. They evolve over time and "mellow" with age. Thus, wines intended for aging are often made from highly tannic grape varieties and can be harsh when opened too young.

How to analyze them during tasting?

During tasting, detecting tannins is straightforward. They are not detected through aromas but through visual and taste analysis of the wine. Visually, tannins can be seen because they contribute to a deeper color. The more intense the color, the more tannic the wine is likely to be.

Try it yourself next time you have a Pinot Noir and a Syrah. Hold the glass up to the light, and you’ll see that a tannic wine will let less light through.

In the mouth, tannins interact with saliva on your palate. The more a wine dries out your mouth, the more tannic it is, which is an indicator of their strength or quantity. Pay attention to the texture (or grain) of the tannins. They can be fine, silky, tender, rich, mellow (with aging), or, conversely, harsh, rough, or coarse. This is an indicator of the tannins' quality and finesse and the wine’s balance. A wine is also described as astringent if it is tannic and has high acidity.

Compare a Malbec and a Grenache, known for their rich tannins but differing in power; or a Gamay and a Grenache, which both have soft tannins but differ in the persistence of their tannins.