In the world of oenology, tannins in wine are among the most important elements for understanding a wine’s structure, flavour and ageing potential. They are often associated with the dry or astringent sensation perceived on the palate, especially in more structured red wines.
But what exactly are tannins? Where are they found in grapes? What does tannic wine mean? And why are some wines more tannic than others?
In this in-depth guide, we explore what wine tannins are, what role they play, how they influence tasting, and the difference between grape tannins, wood tannins and grape tannin as an ingredient.
Key Takeaways
Tannins in wine are natural compounds belonging to the polyphenol family. They are found primarily in grapes and are responsible for many of wine’s sensory and technical characteristics.
- Tannins are mainly present in grape skins, seeds and stems.
- In wine, they contribute to astringency, the dry sensation perceived on the palate.
- They are more abundant in red wines because, during winemaking, the must remains in contact with the grape skins for longer.
- They influence the wine’s structure, body, colour, stability and ageing potential.
- A tannic wine is not necessarily harsh: tannin quality depends on its balance with acidity, alcohol, fruit and body.
What are tannins in wine?
Tannins in wine are naturally occurring plant compounds that belong to the polyphenol family. They are found in many plants and, in wine, come mainly from grapes and from certain stages of the winemaking process.
During winemaking, tannins are extracted into the must primarily through contact with the solid parts of the grape, including the skins, seeds and stems. They may also come from the wood of the barrels when the wine is aged in oak.
From a sensory perspective, tannins are responsible for the characteristic sensation of astringency: the feeling of dryness, roughness or slight friction perceived on the tongue, gums and palate.
This sensation is not a flaw in itself. On the contrary, in well-balanced red wines, tannins contribute structure, depth and ageing potential.
Where are tannins found in grapes?
Grape tannins are concentrated mainly in the solid parts of the berry and the bunch.
Grape skin tannins
Grape skins contain tannins that are generally softer and more mature, especially when the grapes have reached a good level of phenolic ripeness. During maceration, contact between the skins and the must promotes the extraction of tannins, colour and aromatic compounds.
Seed tannins
Grape seeds are an important source of tannins. If they are not fully ripe, or if extraction is excessive, they can impart more bitter, harsh or green sensations.
Stem tannins
Stems are the woody structure that supports the grape berries. They can contribute to a wine’s tannic profile when included in the winemaking process, but they must be handled carefully, as they may introduce vegetal notes and coarser tannins.
Wood tannins
Wine may also contain tannins derived from wood, particularly when it is aged in oak barrels or barriques. In this case, they are not grape tannins, but compounds released by the vessel during maturation.
What effect do tannins have on the taste of wine?
Strictly speaking, tannins do not impart a flavour; instead, they primarily create a tactile sensation. When a wine is high in tannins, the palate may perceive dryness, roughness, astringency or a slight bitterness.
This sensation results from the interaction between tannins and the proteins in saliva. Tannins reduce the mouth’s natural lubrication, creating the dry feeling typically associated with tannic wines.
Well-integrated tannins feel pleasant, refined and gradually developing. By contrast, unripe or poorly balanced tannins may seem aggressive, bitter or disconnected from the rest of the wine.
For this reason, when describing a wine as tannic, it is not only the amount of tannins that matters, but also their quality and their balance with acidity, alcohol, body and aromatic profile.
What role do tannins play in wine?
Tannins play a fundamental role from both a technical and a sensory perspective.
In wine, they help to:
- provide structure and body;
- create the sensation of astringency;
- improve colour stability, particularly in red wines;
- protect the wine against oxidation;
- support ageing potential;
- enhance complexity and balance in full-bodied wines.
In red wines, tannins work in synergy with other grape compounds, such as anthocyanins, which are responsible for red and violet hues. For this reason, managing the tannic component is particularly important in the production of wines intended for ageing.
A wine with well-managed tannins can evolve over time, becoming softer, more harmonious and more complex. During ageing, tannins gradually change and tend to feel less aggressive on the palate.
What does tannicity mean in wine?
Tannicity refers to the intensity and quality of the tannic sensation perceived during tasting.
A wine may have:
- light tannicity, when the astringent sensation is delicate;
- medium tannicity, when the tannins are noticeable but well balanced;
- pronounced tannicity, when the wine has substantial structure;
- unbalanced tannicity, when the tannins feel excessively bitter, green or aggressive.
Tannicity depends not only on the amount of tannins present, but also on how well they integrate with the wine’s other components. Acidity, alcohol, softness, body and fruit ripeness all have a strong influence on the final perception.
A tannic wine is not necessarily difficult to drink. In fine red wines intended for ageing, a well-balanced tannic structure is often a positive characteristic, as it supports the wine and allows it to develop over time.
Tannic wine: what it means and how to recognise it
A tannic wine is one in which the presence of tannins is clearly perceptible on the palate.
The typical sensation is a dry mouth, slightly rough gums and reduced lubrication on the tongue. It is similar to the feeling produced by strongly brewed black tea or certain unripe fruits.
To recognise a tannic wine during tasting, pay attention to three aspects:
- the sensation of dryness after each sip;
- how long the astringency persists;
- the balance between tannins, acidity, alcohol and body.
A well-balanced tannic wine feels structured yet pleasant. By contrast, a wine with overly green or aggressive tannins may seem harsh, bitter or lacking in harmony.
Tannins in red and white wine: the differences
Tannins are generally far more abundant in red wine than in white wine. The main reason lies in the winemaking process.
In red wine production, the must remains in contact with the grape skins, seeds and sometimes stems for a varying length of time. This contact allows colour, aromas and tannins to be extracted.
In white wine production, by contrast, the skins are usually separated from the must much sooner. As a result, tannin levels are generally significantly lower.
However, some white wines can still have noticeable tannins. This is the case with skin-contact white wines, often referred to as orange wines, in which the grape skins remain in contact with the must for a longer period. Ageing in wood can also increase the perception of tannins in certain white wines.
Therefore, although tannins are typically associated with red wines, it is not accurate to say that white wine is always completely free of them.
Which wines are the most tannic?
The most tannic wines are generally red wines made from grape varieties that are naturally high in tannins or produced using extended maceration.
Grape varieties and wines commonly associated with a pronounced tannic structure include:
- Tannat;
- Sagrantino;
- Nebbiolo, including Barolo and Barbaresco;
- Aglianico;
- Cabernet Sauvignon;
- Sagrantino di Montefalco;
- Syrah/Shiraz, particularly in more structured styles.
However, there is no definitive ranking that applies in every case. Tannicity depends on many factors, including the grape variety, ripeness, terroir, maceration time, winemaking techniques and ageing method.
Even two wines made from the same grape variety can be very different if they come from different production areas, vintages or winemaking styles.
Wine tannins: properties, effects and considerations
Tannins are polyphenolic compounds studied for their antioxidant properties and their role in plants. In wine, however, they should be considered primarily in terms of their sensory and technical functions.
From an oenological perspective, tannins contribute to structure, stability, protection against oxidation and ageing potential. From a tasting perspective, they influence astringency, body and persistence.
Caution is needed when discussing the potential health benefits of wine. Although polyphenols are compounds of scientific interest, wine contains alcohol and should be consumed responsibly and in moderation. Any properties associated with tannins should not be interpreted as a reason to consume alcohol for health purposes.
For some people, highly tannic wines may be more difficult to drink or may cause an excessive sensation of dryness. In such cases, softer, less structured wines, or wines with riper and better-integrated tannins, may be more suitable.
Grape tannins and grape tannin extract: what is the difference?
The term grape tannins refers to the polyphenolic compounds naturally present in the raw material, mainly in grape skins, seeds and stems.
During winemaking, these tannins are extracted from the grapes and contribute to the wine’s structure, astringency, colour stability and ageing potential, particularly in red wines.
By contrast, when grape tannin is discussed as an ingredient, the term refers to an extract obtained through the processing and concentration of grape-derived raw materials. In this case, tannin is considered not only as a natural component of wine, but as an ingredient intended for specific industrial applications.
From grape tannins to natural extracts for industry
The role of tannins in wine highlights just how rich grapes are in natural compounds with high functional value. Grape skins, seeds and other parts of the fruit contain polyphenols that can contribute to a wine’s structure, stability, colour and ageing potential.
The same raw material can also be used to produce specific extracts for industrial applications. These include liquid and powdered grape tannin, a natural ingredient used in the wine, food, cosmetics, textile and dietary supplement industries.
Grape tannin is part of Bagnarese’s range of natural food extracts, developed from carefully selected plant-based raw materials using production processes designed to preserve and concentrate their natural characteristics.
Frequently asked questions about wine tannins
Tannins in wine are naturally occurring compounds that belong to the polyphenol family. They come mainly from grape skins, seeds and stems and contribute to the wine’s structure, astringency, colour and ageing potential.
A tannic wine is one in which the presence of tannins is clearly perceptible on the palate. The characteristic sensation is dryness or astringency on the tongue, gums and palate.
Tannins interact with the proteins in saliva, reducing the natural feeling of lubrication in the mouth. This is why a wine rich in tannins can leave a dry, rough or astringent sensation.
Yes, although they are generally present in lower amounts than in red wine. Some skin-contact white wines, such as orange wines, can nevertheless have more noticeable tannins.
The most tannic wines often include structured reds made from grape varieties such as Tannat, Sagrantino, Nebbiolo, Aglianico and Cabernet Sauvignon. However, tannicity also depends on the winemaking method, maceration time, grape ripeness and ageing process.
Tannins are natural compounds found in wine and in many plant-based foods. In wine, they should be considered primarily for their sensory and technical role. Wine should always be consumed responsibly and in moderation because it contains alcohol.
Grape tannins are naturally occurring compounds found in the raw material. Grape tannin extract, by contrast, is obtained through processing and concentration and is intended for specific industrial applications.
Related resources and products
To learn more about tannins, natural extracts and grape-derived compounds, you may also be interested in:
- Liquid and powdered grape tannin
A natural grape-derived ingredient for applications in the wine, food, cosmetics, textile and dietary supplement industries. - Natural food extracts
Bagnarese’s range of plant-based extracts, polyphenols and tannins for industrial applications. - Enocyanin
A natural food colouring obtained from red grapes and belonging to the anthocyanin family.