What are alcohol, tannins and body? What effects do they have on your favourite wine? In this second part, I demystify these structural components. Shiny infographics included
Welcome back to the second part of my two-part blog series which casts light on the structural components of wine. Or, to put it in other words, answers the question: what constitutes wine?
As I wrote in my earlier post, I believe wine lovers need tools in order to confidently discuss wine (and – at the same time – avoid any obnoxious pretentiousness) To do so, it is important to:
- Define the characteristics of wine
- Agree on a common vocabulary
The dimensions that characterizes wine are:
- A set of structural components (sweetness, acidity, alcohol, tannins, body) that makes up the “architecture” of a wine
- The flavours that adorn the wine’s underlying structure
In my previous article, I covered sweetness and acidity in wine. Here, I will deal with the three other important architectural elements that define what we imbibe most (if you are reading this blog, I have an idea of what that is!): alcohol, tannins and body.
Alcohol
Alcohol (or more precisely ethanol) is the main product of fermentation. Yeats awards us the gift of alcohol in exchange for a generous dose of sugar. It goes without saying, the more sugar in the grapes, the more the alcohol in the resulting wine – provided (of course) that fermentation is not artificially stopped.
What affects alcohol?
As a matter of fact, alcohol in a wine is determined by quite a few factors:
- Climate: warmer regions bestow more sugary fruit, consequently these usually yield more alcoholic wines
- Grape variety: some varietals are naturally rich in sugar (grenache, viognier, gewurztraminer) which result in a higher level of alcohol in the wine
- Winemaking decisions: when to pick is the grape is a determining factor; an early picking ensures less alcohol if all other factors are equal.
Alcohol in drinks is measured via alcohol by volume (abbreviated as “abv”). If you see on a wine label 13% abv, it means that 13% of the liquid contained in the bottle constitutes pure ethanol.
The effects of alcohol on wine
The presence of alcohol shows in the wines in two fundamental ways. First of all, alcohol mostly contributes to the body and texture of the wine. Alcohol is more viscous and thicker than water; therefore usually the more the alcohol the fuller the body of the wine.
The second effect of wine’s alcohol content is usually overlooked. Alcohol, in combination with esters and acids, help release and enhance flavours, especially fruity aromas. It acts as a wrapper and catalyser of the aromas condensed in the glass.
The taste and the aroma of alcohol
Interestingly, alcohol has both a taste and aroma. I have already mentioned the taste, as alcohol contributes to the general mouthfeel. You can easily notice alcohol’s aroma when its content is high. Incidentally, we lack a shared definition of “high” here. Personally I would define high alcohol everything beyond 14-14.5% abv.
When the alcohol content of wine is high, you can smell a boozy and burnt sensation. When it’s really high, you actually can’t taste anything other than alcohol! In this case the wine is defined as hot and this adjective – contrary to what happens when applied to people – means nothing good for our vinous beverage!
The burning sensation caused by alcohol can be confused with the effect of acidity. In this case it’s useful to pay attention to the body and to mouthwatering effect to determine whether that feeling is caused by high alcohol or by high acidity.
Tannins
Tannin is one of the most cerebral and alluring topics in the wine world. Inevitably there are a lot of buzzwords surrounding tannins so that’s one more reason to get this aspect straight.
Chemically speaking, tannins are phenols, a class of complex compounds that affect taste, colour and texture of the wine. Apart from tannins, there are other kinds of phenols. These include flavonoids (that influence astringency, colour and mouthfeel) and anthocyanins (which mainly contribute to colour).
Tannins: where are they?
Tannins are mainly present in grape skin, vine stems and oak. Since only red wines are fermented on their skin, we normally talk about tannins when referring to red wines. In red wines, tannins are extracted from the grape skin during the fermentation. Thus winemakers have several techniques to enhance the extraction of tannins when needed or wanted.
Since one of the main sources of tannins is grape skin, its thickness impacts on the tannic presence in different grape varieties. Thick skin varieties have the highest level of tannins: cabernet sauvignon, nebbiolo, sagrantino, tannat. Thin skin varieties normally display low levels of tannins. Pinot noir, grenache, gamay, schiava are a few examples.
In the vineyards, tannins can be measured in different ways. One way to measure tannins is for the winemaker to periodically send samples of berries to a scientific laboratory. A more traditional (and romantic) alternative is to wander the fields from one vine row to another breaking up the small berries and carefully inspecting their seeds. A turn in colour in the seeds from green to brown indicates that tannins are mature.
It’s the sun that makes the tannins evolve. As described previously, during the ripening season sugars and tannins increase (although not always at the same pace), while acidity decreases. Therefore tannin ripeness is one of the factors to bear in mind when determining the time to harvest the grapes.
The dimensions of tannins
Tannins can be looked at from two different dimensions:
- Quantitative: the sheer amount of these phenols (low, medium, high)
- Qualitative: tannins can be unripe (the wine feels grippy and harsh), or ripe (when you don’t taste a tart bitterness, but rather a weighty and smooth feeling on the palate)
Sometimes it can be tricky to determine the level of tannins, especially when the wine sits on opposite directions in the two-dimensional grid above. For example, where the grapes exhibit low unripe tannins or high ripe tannins.
If you feel a lot of astringency in your wine, it’s wise to consider the body before jumping to conclusions. If the body is thin then the wine has a low level of unripe tannins.On the other hand, if astringency is low, consider body and alcohol. A full body signifies that the tannins are ripe and high in level.
The effects and the taste of tannins
Tannins have two main effects on wine:
- Structure: high level of tannins increase the body and contribute to the textural richness of the wine. It can be said that tannins contribute to the architecture, meaning they form the backbone of the wine from a structural standpoint. Tannins are the foundations on which flavours and other elements of the wine are built on
- Ageability: tannins are natural preservatives. High levels of tannins translates into longer cellar ageing potential
On the palate, tannins have a feel and a taste. The former is the typical astringency that causes your mouth to suddenly dry up. You can experience the same sensation eating an unripe persimmon or sucking a black tea bag (if you are into that kind of thing…). Tannins taste bitter – similar to bitter espresso aromas rather than a tart sourness.
The nature and amount of tannins are something to consider when thinking of food and wine pairings. If the right balance is achieved, proteins in food combine with the tannins in the wine resulting in a more pleasant experience overall for both components of the marriage. Such enjoyable culinary experiences are one of the main reasons why high tannic wines are usually suggested in combination with red meat and hard cheese.
Body
This is probably the easiest to discern among the structural components of wine. However, there are different elements that make up a wine’s body, which I will now explain.
Body can be described as the textural impression or the weight on the palate created by a wine. Body is not a single component, but more the combination of several factors: alcohol, tannins, acidity and sugar.
Alcohol is really the main aspect contributing to the body. Crucially, the more the alcohol the fuller the body. Sugar content also enhances body. I’m sure you’ve noticed that sweet wines usually feel viscous to the palate. On the other hand, high acidity decreases the perception of body, providing wine with more freshness and kinetic energy.
Understanding body and its levels
When a wine has ripe tannins, a high level of alcohol and intense flavours, you should have few doubts: you are in front of a full bodied wine. While on the other hand, high acidity, low alcohol and delicate flavours are clear signs of a light body.
When talking about body, people normally use expressions such as: light-bodied, medium-bodied, full-bodied. A useful analogy to grasp the essence of body is milk (skimmed, semi-skimmed, whole milk). On a very general level, we can describe the three main levels of body in wine as follows:
- A light-bodied wine has subtle flavours, feels quite watery and thin on the palate; think skimmed milk
- A full-bodied wine is rich, complex, textured in the mouth; it feels “dense” and thick, with more viscosity on the palate; think whole milk
- A medium-bodied wine sits somewhere in between the two extremes; it can be compared with semi-skimmed milk
If you want to be more precise (that’s the approach WSET Syllabus understandably uses), you can use a five-point scale. In this case, you add terms such as medium+ (between medium and full) and medium- (between light and medium).
Similarly to other structural components, body perception can be influenced by personal habits or preferences. For example, if I’m accustomed to big bold reds, I might categorise a wine as medium-bodied, while for others the same wine can lean more towards the full-body side of the scale. For this reason, I advocate tasting as much wine as you can in terms of different styles and variations to tune your sensitivity and avoid personal bias. Incidentally, it’s also very fun!
Body levels and generalisations
Talking about different grapes or wine styles, I often see people mapping a particular grape or style to certain body level. For example:
- Light body: sauvignon blanc, pinot noir, schiava, German Kabinett riesling, pinot blanc, Beaujolais, Prosecco, Vinho Verde
- Medium body: Chianti, red Bordeaux, red Burgundy, pinot gris, cabernet franc, Valpolicella, mencia
- Full body: Brunello di Montalcino, cabernet sauvignon, merlot, zinfandel/primitivo, Australian Shiraz, Châteauneuf-Du-Pape
The above are broad generalisations which can be useful for a general understanding of what you can expect from a certain grape or style. However, generalisations are like cliches – there may be some truth to them but they are always to some extent imprecise and can often not be true at all.
Pick any grape or style and if you explore, you will find a plethora of body types. These wines will differ (sometimes hugely), due to geographical provenance, terroir, vintages, winemaking decisions. And today, even more than a decade ago, the wine world is much more diversified and heterogeneous than it has been in the past.
For example, a red Burgundy (made from the pinot noir grape) is typically listed as a medium-bodied wine. However, you can find some light-bodied examples – especially from colder districts and more affordable appellations (Hautes Côte de Beaune, Beaune, Savigny). But some terroirs or producers (notably from Grand Cru vineyards or some sites from Côte de Nuits, for example Gevrey-Chambertin) produce full-bodied pinot noir with concentrated flavours and higher levels of alcohol.
Final thoughts
I hope you’ve enjoyed my two part series on What constitutes wine? If you missed or need a reminder about the first part, which focused on sweetness and acidity, you can find it here. I trust you now feel confident and eager to find new wines and discuss these with your friends, family and other wine lovers – including myself, if you want!
I tried to break down the architectural elements that characterise wine, so you can appreciate the role of each and how they impact the style and taste of your favourite drink. If you fancy a challenge, next time you sip a glass of wine, try to identify the characteristics of each structural constituent. Does the wine have some sugar? What does the acidity feel like? Can you correctly guess how alcoholic it is? If it’s a red, does it show a pronounced astringency? Finally consider the body – it is a result of the combination of the other elements. On the palate is the wine more similar to skimmed milk (light-bodied) or whole milk (full-bodied)?
Between one sip and the other, remember to subscribe to Wine and other Stories (see below)… Next week, I will unveil my Wine of the Month for July. See you there!
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