Phenols and astringency: Dry tongue in wine explained

During a blind wine tasting, someone handed me a glass of young red wine and when I tasted it I noticed that dry, almost scratchy sensation on my tongue that lingered for a few seconds before fading away. The instructor explained that what I was feeling was not a flavor but a tactile sensation caused by tannins. I kept thinking about that for days: what exactly do these compounds have that makes them dry out the mouth like that? I researched phenols and astringency in wine in depth, and what I found also has direct connections with coffee. In this article, I’ll tell you everything I learned. Let’s begin!

Phenolic compounds in grapes and their origin

The origin of phenolic compounds in grapes is intrinsically related to the nature and evolution of the plant. These compounds, highly relevant in the world of wine, are essential for understanding the quality and diversity of different styles.

Types of phenols present in the skin and seeds

In grapes, phenols are found predominantly in the skin and seeds. They can be classified into three main groups: tannins, anthocyanins, and phenolic acids.

Condensed tannins and their function in red wines

Condensed tannins are crucial in red wines. These compounds provide astringency and structure the wine, offering a mouthfeel that can range from roughness to smoothness. Their presence is key to the wine’s longevity, since they contribute to its aging.

Hydrolyzable tannins and their contribution during aging

Hydrolyzable tannins are released mainly during the barrel-aging process. When wooden barrels are used, these tannins interact with the other components of the wine, enriching its palate and softening the overall texture. This process transforms and enhances the complexity of the flavor profile.

Influence of skins and stems on phenolic composition

The skins and stems play an essential role in the phenolic composition of wine. During winemaking, the prolonged contact of the must with these parts of the grape ensures greater extraction of tannins and other beneficial compounds, producing a more robust wine with greater character.

Astringency: sensation in the mouth and dry tongue

Astringency is one of the most interesting and complex characteristics of wine, as it can completely transform the tasting experience. The interaction of tannins with proteins in the mouth is the main cause of this sensation.

Mechanism of interaction between tannins and salivary proteins

When tasting tannin-rich wines, phenolic compounds interact with salivary proteins and the oral mucosa. This binding creates a coagulation phenomenon that reduces the mouth’s natural lubrication. As a result, a sensation of dryness and roughness, known as astringency, is produced.

How natural lubrication affects the tactile sensation

Saliva, being a mixture of water, enzymes, and proteins, acts as a smoothing agent. When tannins coagulate these proteins, the mouth feels less lubricated, intensifying the tactile sensation of dryness. This is especially noticeable at the end of the tasting, when astringency becomes more evident.

Difference between astringency and other tastes in the glass

It is vital to distinguish between astringency and other tastes that can be found in wine. Astringency is felt as a texture in the mouth, whereas other tastes, such as acidity or sweetness, are perceived more directly as flavors. In this way, each of these characteristics contributes to the wine’s complexity, enriching the sensory experience.

Maceration process and tannin extraction

Maceration is a fundamental process in red wine production, as it allows the extraction of essential components that influence flavor and texture.

Role of must contact with the skins in red wines

The prolonged contact of the must with the grape skins is essential. During this period, tannins and anthocyanins are extracted, giving the wine its color and astringency characteristics.

Duration and temperature as key factors

The duration of maceration varies according to the type of wine desired. Heat can accelerate extraction, but care must be taken not to exceed the limits, as this could lead to excessive astringency. In general, this process is carried out at controlled temperatures between 20 and 30 °C.

Comparison with white wine production

Unlike reds, white wine production generally involves a quick separation of the must and the skins. This results in lower tannin extraction, offering a lighter and fresher profile, without the notable astringency of reds.

Impact of maceration on the texture and color of wine

Maceration not only affects the flavor of wine, but also its texture and color. An appropriate maceration time produces a wine with greater complexity on the palate and a more intense color, which is appealing to drinkers.

Aging and the contribution of tannins from the barrel

Barrel aging is a fundamental process in winemaking, as it contributes to the complexity and structure of the final product.

Types of oak and their characteristics in maturation

American oak barrels: flavors and astringency

American oak is known for imparting intense flavors and aromas of vanilla and coconut. This type of barrel can increase levels of astringency due to the greater amount of tannins present in the wood. Wines aged in American oak tend to show quicker maturation and a more robust expression on the palate.

French oak barrels: subtleties and smoothness

French oak barrels are prized for their elegance. Their subtler toasting process develops notes of spice and earthy aromas. Aging in this type of barrel usually results in a smoother texture, helping to integrate tannins more harmoniously and minimizing the sensation of astringency on the palate.

How aging modifies the sensation of astringency on the palate

The time a wine spends in the barrel has a significant impact on its astringency profile. As the wine ages, the barrel tannins integrate and soften, balancing the sensation of dryness. This allows the wine to evolve toward a fuller expressiveness, where the tannins amalgamate with the other phenolic compounds.

Organoleptic differences between red and white wines regarding tannins

The variety of tannins in red and white wines generates significant differences in the tasting experience.

Influence of the pressing process in white wines

Pressing limits the contact of the must with the skins and seeds of the grape, preserving freshness and acidity. As a consequence, white wines show a much lower level of astringency compared with reds.

Presence and perception of tannins in different grape varieties

Different grape varieties play a fundamental role in the quantity and quality of tannins present. Varieties such as Tempranillo or Cabernet Sauvignon are rich in tannins, providing more robust wines. In contrast, grapes such as Pinot Grigio or Chardonnay contribute greater smoothness, creating a perception of freshness without high astringency.

Consequences for the sensory experience of the consumer

In reds, tannins can create a sensation of body and richness. In whites, their absence facilitates a lighter and more refreshing experience. This influences consumers’ choices depending on the occasion and their personal preferences.

Balance in wine: smoothness versus excessive astringency

Achieving the perfect balance between smoothness and astringency is fundamental in winemaking.

Identifying green tannins and their negative impact

Green tannins, coming from grapes that are not fully ripe, can cause a sensation of excessive astringency in the mouth. Their roughness is uncomfortable for many drinkers and is associated with a crunchy rather than silky texture.

Strategies for achieving a silky texture on the tongue

To achieve a more pleasant tasting sensation, it is crucial to select well-ripened grapes, optimize maceration time to gently extract tannins, and implement aging techniques that soften the texture, such as the use of suitable oak barrels.

Recommendations for choosing wines according to astringency preference

For those who prefer more moderate astringency, it is advisable to opt for red wines with longer aging (which softens the tannins), explore more approachable varieties such as Merlot or Pinot Noir, and consult tasting notes before buying a bottle to identify the expected tannin level.

Frequently asked questions about phenols and astringency in wine and coffee

What is the difference between astringency and bitterness in tasting?

Bitterness is a taste perceived by the taste buds and has a chemical nature. Astringency, by contrast, is a tactile sensation: the dryness, roughness, or “dry tongue” feeling that occurs when tannins precipitate salivary proteins. A wine or coffee can be bitter without being astringent, and vice versa, although both often appear together in beverages with a high concentration of phenolic compounds.

Does coffee also contain tannins and produce astringency?

Yes. Coffee contains chlorogenic acids and other polyphenols that can produce some astringency, especially in coffees with prolonged extraction, overextraction, or lower-quality coffees. Well-extracted specialty coffees tend to have little astringency, whereas overextracted espressos or overly long filter coffees can present that sensation of dryness and roughness in the mouth.

Why does eating cheese or meat soften the astringency of wine?

The proteins in foods such as cheese or meat compete with salivary proteins to bind to tannins. By providing more proteins that can precipitate tannins, the astringent effect on saliva is reduced. That is why pairing red wines with protein-rich foods is so classic and effective.

Can the astringency of wine decrease over time?

Yes. During aging and bottle maturation, tannins polymerize and progressively soften, reducing astringency and creating a silkier texture. It is one of the reasons why highly tannic wines improve notably with years in the cellar. Opening them too early can result in a texturally uncomfortable experience.

How can astringency be evaluated during a tasting?

Astringency is evaluated by paying attention to the tactile sensation in the mouth after swallowing or spitting out the wine: do you feel your mouth dry, your gums tight, your tongue rough? Intensity (low, medium, high) and quality (rough and green vs. silky and ripe) are the two key parameters. With practice, you learn to distinguish it from bitterness and to appreciate it as a positive structural element when it is well integrated.

At Coffee Sapiens, we never stop researching to explain the science behind every cup and every glass. Understanding phenols and astringency makes you a better taster, both of wine and coffee. Thanks for being here, Coffee Lover!

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