What Are Tannins, Exactly?
In the wine world, few terms are tossed around as frequently — and understood as loosely — as “tannins.” Ask a casual drinker what they are, and you might hear, “It’s that drying feeling in red wine.” While not entirely wrong, that’s just the tip of the iceberg. Tannins are fundamental to a wine’s structure, ageing potential, and even its food-pairing possibilities. So let’s roll up our sleeves and break down what they are, how they work, and why they deserve more attention than they usually get.
The Chemistry Behind the Texture
Tannins are polyphenolic compounds, naturally occurring in the skins, seeds, and stems of grapes. They are also present in oak, which is why barrel ageing often enhances a wine’s tannic character. Chemically speaking, tannins bind to proteins — which is part of the reason they create that astringent, drying sensation on the palate. Think of the puckering sensation you get when sipping oversteeped black tea: that’s tannin in its purest, non-alcoholic form.
The real beauty of tannins lies in their interaction with saliva. Our saliva contains proteins designed to lubricate the mouth. Tannins bond with those proteins, essentially “deactivating” them and leaving the inside of your cheeks feeling rough or dry. It’s tactile, not taste, but profoundly influences our perception of wine quality and mouthfeel.
Where Do Tannins Come From?
There are three primary sources of tannin in wine:
- Grape skins: Especially rich in red grape varietals. Thicker-skinned varieties like Cabernet Sauvignon naturally produce more tannic wines.
- Seeds and stems: Typically more bitter and aggressive. Their extraction is carefully controlled during winemaking.
- Oak barrels: During maturation, wines stored in new oak—especially French oak—absorb oak tannins that can lend structure and complexity.
Each source contributes differently. Winemakers must manage tannin extraction with surgical precision, as these compounds evolve throughout fermentation and ageing. Over-extraction can lead to harsh, green bitterness; under-extraction may result in flabby, short-lived wines. It’s a balancing act based on grape variety, vintage conditions, and intended style.
Do All Wines Contain Tannins?
Almost all red wines contain tannins. White wines may contain trace tannins, particularly if the grapes underwent skin contact or the wine was aged in oak, but their presence is typically subtle. Orange wines — white wines fermented on their skins — are a clear exception, often exhibiting a tannic structure akin to that of a light red.
As for sparkling wines, the level of tannin is usually minimal, though vintage Champagnes or those vinified in oak might show a faint grip. Meanwhile, rosés occupy a fluid middle ground; their tannin level depends on maceration time and grape selection.
Tannins and Grape Varieties: Not All Created Equal
Different grape varieties exhibit distinct tannin profiles. Here are a few examples to illustrate the breadth of variation:
- Nebbiolo: High in both acidity and tannin. Even in youth, it can be fiercely astringent, though patient cellaring rewards the drinker with elegance and complexity.
- Cabernet Sauvignon: Robust tannic backbone, amplified by oak ageing. Its global appeal lies partly in this structure, which grants it longevity and food-pairing flexibility.
- Pinot Noir: Generally low in tannin, with gentle grip and silkiness. Yet, even here, clonal selection, oak ageing and terroir nuances can alter impressions.
- Malbec: Plump and juicy but with firm tannins, especially from higher-altitude vineyards like those in Mendoza.
Understanding the inherent tannic tendencies of a grape is key to decoding a wine’s style and potential ageing trajectory. And for sommeliers — or ex-sommeliers like me — it’s also an invaluable guide to food pairings.
How Tannins Influence Ageing Potential
If you’ve ever wondered why some wines can survive for decades while others peak within a few years, tannins are a major part of that equation. Alongside acidity and alcohol, tannins act as a preservative element, protecting wine from oxidation while it matures.
Over time, tannins polymerize — meaning they bind into longer molecular chains that taste and feel smoother. This transformation is what gives aged reds their velvety finesse and complexity. A 1996 Bordeaux may have been aggressively tannic in its youth, but with time, the edges soften, revealing secondary and tertiary notes of leather, tobacco, and earth.
Still, not all tannic wines evolve gracefully. The balance between fruit concentration, acidity, alcohol and tannin must be just right. Excessive tannin without enough fruit weight? You’ll end up with a wine that ages into austerity, not grace.
Food Pairing: The Role of Tannins on the Table
Why do red wines pair so well with red meat? It’s not a cliché — it’s chemistry. Remember how tannins bind with proteins? When enjoyed with a juicy steak, tannins cling to the meat’s proteins rather than the ones in your saliva. This reduces their drying effect and allows the wine’s other attributes — fruit, spice, minerality — to shine through more vividly.
Here are some reliable pairings that highlight tannin interactions:
- Cabernet Sauvignon & Ribeye: The fat and umami of the ribeye counterbalance the wine’s firm structure.
- Nebbiolo & Truffle Risotto: While it might sound counterintuitive, the creaminess of the risotto smooths out the wine’s angularity, and aromatic truffle mirrors Nebbiolo’s intensity.
- Malbec & Barbecue: Char and smoke complement the bold tannins and dark fruit, especially in oak-aged styles.
Conversely, tannic wines can clash horribly with dishes high in spice, acidity or bitterness. Pairing a young Tannat with a bitter endive salad, for example, is a shortcut to palate fatigue.
Common Misconceptions About Tannins
Let’s debunk a few myths, shall we?
- Tannins cause wine headaches: Despite persistent anecdotes, there is no scientific consensus linking tannins to headaches. Histamines, dehydration, or alcohol sensitivity are more likely culprits.
- Tannins = bitterness: While overextracted seed tannins can be bitter, not all tannins are unpleasant. Well-managed tannins produce finesse, grip, and longevity. Bitterness can also stem from other compounds, including phenolics and volatile acidity.
- Smooth wines have no tannins: Not true. A well-aged Burgundy may feel silky, yet it can still possess resolved tannic structure that contributes to complexity and length.
The Winemaker’s Hand: Managing Tannin Extraction
Crafting the right level of tannin is one of the most technical aspects of winemaking. It begins during fermentation, when skins, seeds, and juice interact. Here, winemakers choose between gentle pump-overs or more extractive punch-downs, cold soaks or extended maceration — each deciding factor affecting the final perception of tannin.
For example, the use of whole clusters during fermentation, as increasingly seen in Pinot Noir production, introduces stem tannins that add complexity — but also risk greenness if not properly judged. Similarly, the decision to age in new oak for 12, 18, or 24 months directly influences tannic levels and integration.
Winemakers train for years to master this balancing act. The right manipulation brings harmony and age-worthiness; the wrong choices can render a wine nearly undrinkable.
Your Palate, Your Preference
Much like acidity or sweetness, tannin tolerance varies from person to person. Some drinkers revel in the scrape of a young Barolo; others find it abrasive. That’s perfectly fine. Developing your palate means learning your own thresholds — and being curious enough to test them.
Next time you’re exploring a flight, pay attention to the texture. Does the wine dry out your tongue? Does it linger on the gums? Note whether the sensation is coarse, fine-grained, chalky, or velvety. These are the fingerprints of tannin, quietly shaping your tasting experience.
In the end, understanding tannins enriches not just your vocabulary, but your enjoyment. When we go beyond “It’s dry” and start asking “Why is it dry?” — that’s when we move from drinking wine to tasting it.