What Are Tannins in Wine: All You Need to Know

It’s Friday night, you’ve had a long week, it’s time to bust open a bottle of vino. But as you sit there, sipping your prized Nebbiolo or Cabernet Sauvignon, something strange starts happening … Suddenly your lips are stuck to your teeth, your tongue has turned to blotting paper and you feel like you have just drunk all the grains of sand in the Sahara. Yummy, sounds delicious, doesn’t it? Well, actually, to wine lovers, the answer is yes. 

Say the words tannic wine to any non-wine enthusiast as they will probably turn their nose up. I mean, what I’ve just described doesn’t sound very nice, does it? After all, aren’t tannins used in the production of leather  – hence the “tanning process” (yes, they are). I mean, do you really want to drink the same thing that is used to age leather? But to the initiated, this is the epitome of good wine. 

What Are Tannins in Wine?

There is a bit in Dirty Dancing when Patrick Swayze says to Jennifer Grey that, “music isn’t something you hear, it’s something you feel” (or words to that effect). It is more or less the same with tannins in wine – they are not something you taste, but something you feel. Tannins are responsible for that “drying” sensation in your mouth when you taste your wine. They are a bitter-tasting chemical compound that is part of a larger group called polyphenols. Tannins occur almost everywhere in nature, from the barks of trees to leaves, skins and stems of various fruits and flowers. And yes, we include red grape skins in that collection.  

The purpose of tannins is not, surprisingly, to dry out our mouths when we are drinking our favourite Syrah or Sangiovese. Their primary role is to make unripe fruits and seeds taste fairly disgusting, therefore dissuading animals from eating them and potentially poisoning themselves. Isn’t Mother Nature clever? 

Tannin molecules are much larger than other molecules found in polyphenols. Because of their size, they easily bind with proteins, including those found in our saliva. It is this sexy little chemical reaction that creates the astringent, “mouth-coating”, drying sensation in red wine, so loved by some, and so hated by others. 

Still if you’re a wine investor (make sure you use a convenient wine investment app) you have to know more about tannins in wine.

What Are the Health Benefits of Tannins?

If you could only drink one thing for the rest of your life, hands up who would choose red wine? Yes, us too. And don’t feel bad about your choice, either. Even if your wallet and waistline won’t thank you for it, your heart might. Because the high tannin content in red wine is actually quite good for you. Like all phytochemicals, the tannins in red wine have a number of health benefits that range from combating inflammation to reducing your risk of heart disease. They’re also natural antioxidants, which neutralise free radicals and fight against oxidative stress. This antioxidant activity in tannins is the reason for many of their health benefits, which include protection against heart disease, cancer and allergies. They also help balance your blood sugar and have been proven to slow the progress of neurodegenerative brain diseases such as Parkinson’s and Alzheimer’s. And because of their neuroprotective effects, tannins are also heralded for their strong antidepressants qualities, helping to boost moods and overall well-being. We’re still talking about the tannin level, and not the alcohol in the wine here, right? 

So, with all those wonderful properties, why are tannins still considered the bete noir of vin rouge? Regrettably, it’s not all tantastic news. Tannins are also anti-nutrients, meaning that they block the absorption of certain nutrients, notably iron. So if you’re anaemic, high tannin wines are a big non for you.

Wine Tannins: Are They Good or Bad?

If you’re a budding (or established) wine taster, you need to talk the talk if you’re going to walk to walk. Any wine critic worth their salt will have already memorised certain keywords, and tannin is a key concept that comes up time after time. But why is it so important in wine? 

Tannins play an exceptionally important role when it comes to age worthy wine. The evolution of the grape tannins contributes to the wine’s evolution in both barrel and bottle, notably the overall aroma, flavour, colour and textural characteristics. As the tannic molecules fix onto the proteins and start to polymerise (the scientists among you will know what that means, otherwise it’s not important to know), the flavours in the wine start to change and sediment is formed. The polymerised tannins soften in taste (ergo they no longer taste bitter or astringent). But, as a key element in the structure of the wine, the presence of tannin will give the wine a greater ageing potential – that mouth dryness caused by tannic astringency will make wines feel ‘fresher’ as the primary fruit aromas get lost.

This is why some red wines, particularly those with high acidity and a high tannin structure are best when they have been laid down for a few years. You must have seen comments in reviews where the critic mentions “drink after x amount of years”? This is what they mean; only after that amount of time will the tannins have started to soften, and will offer the drinker an enjoyable experience. Know that depending on the structure of the wine (as well as the quality of the grapes and terroir), some wines are capable of ageing up to 50 or more years. So even if James Suckling suggests drinking after five or so years, that doesn’t mean that’s your only option. That just means the drinking window can be opened then, and could potentially stay open for some time.

I couldn’t mention tannin in wine and ageing without a little side note on En Primeur. Despite the literal French translation of en-primeur being “in its prime”, EP wine is anything but. As EP is tasted from the barrel only around 6-8 months after it has first been made, tannin content is very high and harsh, and thus greatly affects the wine’s taste. EP wine is not a true reflection of what the vintage will taste like. En-Primeur (I prefer the English term “Futures” as it’s far more indicative) wines are sold to collectors for as much as 30% less with this in mind. Collectors and negociants however spend years understanding each estate’s terroir and winemaking processes so that they can make an educated guess (and save a fair amount of cash) when it comes to Futures season. In short, EP wines are a bit of a gamble; they may be less expensive to buy, but there is no guarantee of how they will age. 

Which Wines Are High in Tannins?

In general, red wines are higher in tannin than whites. This is because reds are macerated with their skins in order to extract that gorgeous deep ruby colour. Think leaving a teabag in the pot to stew and you have the right idea. White wines are the opposite – in fact, the clearer the better with whites (and rosés) – so they are separated from their skins very soon after the grapes are crushed. Winemakers’ style and grape varietals will also affect the tannic structure. It is even not unheard of to add powdered tannin to the wine in order to give it a little extra va va voom. 

Therefore the most tannic wines are big, bold, beautiful reds such as ones made with Nebbiolo, Cabernet Sauvignon, Syrah, Sangiovese, Montepulciano and Malbec. The Italian red wine grape Sagrantino is noted for its particularly tannic properties, but as the grape is so difficult to grow, wines are rare. However, it is the South American grape Tannat (widely planted in Uruguay) that is on the top of the leader board here: studies have shown this to be the grape that contains the highest polyphenols of all red grape varieties. Salud!

Which Wines Are Low Tannin?

Whether you want to avoid tannins for health reasons (see above), because you don’t want to wait 10-15 years to drink your bottle, or simply because you don’t like the taste of tannins, all is not lost. Not all wines, even red wines, are tannin-tastic. Wines that feature a preponderance of Pinot Noir will lean towards a lower tannin level, as the grape variety’s skin is much thinner, and therefore lower in polyphenol. Barbera wines from Piedmont in Italy are also a good option, but be careful to not get confused with the region’s star grape Barolo, which produces highly tannic wines. Whites are usually low tannin wines, notably Sauvignon Blancs, Pinot Grigios and Rieslings. Regrettably, there is no such thing as a tannin free wine. 

One final word to the wise. In the case of high tannic wines, let them breathe. This won’t affect the level of tannins, but the oxygenation process that happens upon decanting will open up the wine’s flavours and soften the taste.

Have you a preference for high or low tannin wines? Why not check out our piece on how to distinguish a variety of wine flavours for a little extra help!

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