Samui Wining & Dining
Tannin Can’t Be Beaten

Sure, tannin is great for curing leather but it also
forms the building blocks of every wine.


23The word ‘tannin’ is commonly used in wine circles. But understandably, many people aren't exactly sure what it means.


Well, the often-misunderstood tannin is a key component in wine. It’s the hard-to-describe element that, once imparted onto a wine by extended contact with grape skins, gives it its body. I believe the tannins could best be explained as the ‘building blocks’ of a wine. And it’s the tannins that should be most credited when an expert proclaims a wine ‘well structured’.


Of course, the term ‘tannin’ is an old one. And comes from the practice of using extracts from plants to cure leather (tanning). This process exploits one of the key properties of tannins – they have a strong tendency to link up with a range of other chemical entities, most particularly proteins. Applied to animal skins, tannins cross-link the proteins, turning something rather soft and floppy into a material that’s tough and inert enough to make shoes, belts, saddles and whips with. Tannin doesn’t, then, sound at all pleasant to have around, let alone find in a glass of wine. But that’s the very nature of tannin. It’s designed to be unpleasant in the early part of a grape’s life.


Tannins, found principally in the bark, leaves and immature fruit of a wide range of plants, are thought to play the role of plant defender. They have an astringent, aversive taste that is off-putting to wannabe herbivores. As an animal or insect begins to munch on plant tissue, the tannins are released from and bind with the proteins and other cell components, making them taste unpleasant and rather indigestible. Significantly for winemaking, the grape vine exploits tannins in a rather clever way in its fruit. Grapes start life small, green, mean, and extremely bitter and astringent, through a combination of searingly high acidity and green, aggressive tannins. The grapes are also camouflaged green, the same colour as the rest of the plant. This is because the grape berry’s function in life is to act as a carrier for seeds, and it doesn’t want birds to eat them all before they’re ready. The idea is that the palatability and attractiveness of the berry is timed to coincide with the ripeness of the seed.


And at the right time, the berry changes colour so it stands out, acidity diminishes, sugar increases and the bitter tannins soften, in order to make it attractive. The birds eat the berries, some time later nature takes its course, and the seeds are deposited in a new location.


The tannin in wine will do a similar thing. In time, it mellows and blends with the other chemical properties making up the wine’s character. It’s a massive contributor to the texture and personality of a fine old red wine. It’s the harmony between tannin and a wine’s fruit, acid, and, very importantly, alcohol, which creates the conditions both for longevity and the potential to mature gorgeously by developing, over a few years, a seductive feel and flavour. And, not to be overlooked, the finely balanced tannins in wine play a big part in food compatibility, helping compete with strong robust meaty or game flavours.


Tannin is instantly recognizable on the palate by the shriveling up of the sides of the mouth and the tingling sensation on the sides of the tongue (over-brewed stale black tea is very tannic). In an aggressively tannic young wine, the flesh of the mouth cavity is actually experiencing the process by which animal skin is transformed when tannin is used to ‘tan’ hides!


If I may continue with the building block theme, I often think tannin is like a building’s inner brickwork. It holds up the wine in many instances, yet is not obvious to certain senses; namely sight and smell. It has little colour to contribute and, being without aroma, it cannot be detected by the nose. Though, having said that, I hardly ever find a deep rich wine with a compelling aroma that does not posses tannin in some degree or another. With white wines, the presence of tannin is less prevalent, because it’s had far less exposure to the grape skins. I’ve heard that tannin levels in white wines are one sixth of that found in reds. However, without doubt, the lifted aroma of a deep golden Chardonnay, for example, which has been produced with a certain amount of grape skin contact and oak-barrel aging (tannins are found in wood too) contains noticeably tannic flavours. But, for me, high levels of tannin are best balanced with high levels of alcohol. This is one of the areas of wine-making that requires the sort of mastery only acquired after years of experience. Certain highly alcoholic Californian Zinfandels, 14.5 % alcohol or so, which takes several years to develop ripe fruity lushness, are remarkably well balanced (in spite of this weight of alcohol) because of the richly muscled tannins present. And the classic 13.5 % alcohol Chateauneuf-du-Pape, which seems routine for its appellation, will only be fine if it has powerful tannins to counter its alcoholic force.


Somewhat disappointingly, I find many New World red wines with high alcohol content lacking in tannins (which is probably a symptom of the need to make ready-to-drink wines in the modern consumer age). To my mind, just like the brickwork, invisible behind the elegant plaster mouldings of a fine historic building contributes something of which, if it were absent, would not permit the complexity of the surfaces to be so bold and striking, tannin such a fundamental part of a fine wine that it simply can’t do without it.


However, having let you read this – my conscience now demands that I confess my ‘building block’ tannin metaphor has no real basis in scientific or wine-making fact. It’s merely my 20 years of musing and empirical boozing offering a point of view!


Peter James

Wine Guru


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