What is tannin?

Are You a Fan of Tannic Wines?

Do you prefer rich, tannic wines like the famous Cabernet Sauvignons, or do you lean towards less tannic options like Pinot Noir? Whether they are soft, firm, mellow, evolved, or young, tannins are omnipresent in wine tasting.

But what exactly are tannins? Where do tannins in wine come from, and how can you recognize a tannic wine? Do tannins have a taste?

This term, commonly used by wine enthusiasts, is paradoxically not very well known. Here, we provide all the keys to successful wine tasting.

To start, here’s a hint: tannins are not found in white wine, but they are present in tea.

What Are Tannins?

Tannins are indeed found in tea, but they are present in all plants. More precisely, tannins are molecules from the polyphenol family that help protect plants and take on different chemical forms depending on the plant variety. Therefore, there isn’t just one tannin but a multitude of them!

These molecules can infuse into a liquid and affect its aroma and, most notably, its texture. In the case of wine, tannins most often come from:

• The Grapes Themselves: The grape bunch is a plant rich in tannins. They are contained in the grape skins, the seeds, and also in the stem (the plant part that holds all the berries together).

• The Barrels Used for Aging: When a wine is aged in barrels, it comes into contact with tannins from the wood, which then infuse into the wine. This gets complicated! The type of wood, the number of wines it has aged, and even its toasting level all impart different tannins to the wine.

A wine will be more or less tannic depending on the type of grape used, the duration of maceration, whether barrels were used for aging, and the length of aging, as well as the quantity of tannins present in the wood. The amount of tannins, or phenolic compounds, is measured by the permanganate index. This index measures the amount of oxygen consumed by the oxidizable substances (polyphenols) contained in a liter of wine.

To give you an idea, here is the average index by type of wine:

• 1 to 12 for white wines.
• 25 to 35 for rosé wines.
• 40 to 150 for red wines.

Recognizing a Tannic Wine

Tannins are relatively easy to spot. In fact, you may have already experienced this: if you steep your tea longer than necessary, it becomes darker, more bitter, and leaves a drying sensation on your tongue. These are (among other things) tannins.

• Texture: It is easy to recognize a tannic wine (and estimate how tannic it is) by focusing on the sensation on your tongue. Use your tongue to spread the wine across your palate. If the wine is tannic, you will quickly feel a rough sensation. It is no coincidence that tannins are often described by their “grain” as a texture.

• Color: While tannins do not directly impact color, they are accompanied by another type of molecule. Anthocyanins, also present in grape skins, infuse alongside tannins. Generally, a darker wine is more likely to be high in tannins than a lighter wine. However, some grape varieties (notably in Italy) can be very dark without being high in tannins, so be cautious of this assumption!

Color is an indicator, but the only surefire way to measure tannins is to assess the texture in the mouth.

What Are the Most Tannic Wines?

Tannins in wine mainly come from the grapes. There are many types of grapes, known as varieties. Some varieties have thicker or more concentrated skins, thus producing tannins in higher concentration and quantity.

These varieties are mostly found in the south: indeed, thick-skinned grapes resist high sunlight and need it to reach maturity. The most tannic wines are likely those from the South-West, made from Tannat and Malbec grapes.

Next, we find wines from the Bordeaux region (Cabernet Sauvignon, Merlot), Languedoc-Roussillon (Grenache, Syrah, Mourvèdre, Carignan, etc.), Provence, and Southern Rhône (Grenache, Mourvèdre, Syrah, Cinsault, Tibouren).

However, even grape varieties that are not inherently tannic can develop tannins during aging. It is also possible to find wines made from Pinot Noir (Burgundy) or Cabernet Franc (Loire) with a good level of tannins. For these references, refer to the winemaker’s notes!

Whether you are a fan of tannic wines or not, you are sure to find something to your liking at Avenue des Vins' online store. Enjoy your tasting!

FAQ - Tannin

What exactly is tannin in wine?

Tannin is a molecule from the polyphenol family found in every plant. In wine, it mainly comes from the grape skins, seeds and stems, as well as from the wood of the barrels during aging. It shapes the texture and structure of the wine more than its aroma.

How can you recognise a tannic wine when tasting?

Spread the wine across your palate with your tongue: a tannic wine leaves a rough, drying sensation in the mouth, a bit like over-steeped tea. Colour offers a clue, as darker wines are often more tannic, but only the texture in the mouth truly confirms it.

Do tannins have a taste?

Tannins are felt rather than tasted. They leave a drying sensation and sometimes a slight bitterness on the tongue, known as astringency. Tannins are often described by their grain, because it is really a matter of texture.

Which wines are the most tannic?

The most tannic wines often come from South-West France, made from Tannat and Malbec grapes. You also find firm tannins in Bordeaux (Cabernet Sauvignon, Merlot), Languedoc-Roussillon, Provence and the Southern Rhône. These thick-skinned varieties naturally concentrate more tannins.

Are there tannins in white wine?

White wine contains very little: its tannin index sits between 1 and 12, compared with 40 to 150 for reds. Tannins come mainly from the skins and seeds, which play a small role in white winemaking. You will actually find more tannins in tea than in a glass of white wine.