The 6 Keys to Veraison, the Adolescence of Grapes

Veraison is a key phase in grape growth

During veraison, grapes change from green to pale yellow, beginning the final phase of their life cycle: ripening

Adolescence is a crucial time in people’s lives. A stage in which our bodies and minds are transformed to move from childhood to adulthood. This transformation occurs over a handful of fascinating, complex and exciting years. What is known as adolescence in humans is called veraison in grapes. A brief stage in the life cycle of the raw material from which wine is made, but of vital importance.

Just as happens to people during adolescence, during veraison, grapes change on the outside (their colour changes), but also on the inside (sugars, phenolic compounds, etc.) in such a way that their growth stops and the grapes are prepared to start the final stage before the grape harvest: ripening.

This process occurs at the end of July and the beginning of August. The grapes take advantage of the rest of the summer with its sun and high temperatures to complete their ripening and prepare for the most critical moment in the Pazo Baión winery: the harvest.

Below, we will analyze some of the keys to veraison, a phase as brief as it is fascinating in which the Pazo Baión team gives its best to achieve a raw material of the highest quality.

Chlorophyll and phenolic compounds

As we mentioned earlier, veraison is an external transformation of the grapes and a change in which the protagonist is colour.

Until veraison, grapes are green due to the abundance of chlorophyll. However, during veraison, the chlorophyll gives way to phenolic compounds (polyphenols) and the albariño grapes, such as those grown on the Pazo Baión property, gradually acquire a pale yellow colour, which floods the vineyards of the D.O. Rías Baixas during August.

Is this change only relevant at a visual level? No. The grape skin not only changes colour, acquiring the hue of the grape variety, but also becomes thinner and more elastic. In addition, polyphenols produce two changes that affect aroma and flavour:

  • Phenolic compounds determine the primary aromas of wines linked to the grape variety. For example, in the case of Pazo Baión, the floral and fruity notes, typical of Albariño, can be appreciated.
  • Polyphenols, which come from the pips but which, after veraison, rapidly concentrate in the pulp and skins, give the wine two typical characteristics: astringency and bitter taste.

The revolution of sugars and acids

If an idea is installed in the collective imagination about adolescents, it is that they live with hormones in turmoil. During veraison, grapes also undergo a small revolution linked to sugars and acids.

Until veraison, grapes have a low sugar level, with glucose predominating over fructose. After veraison, the sugar level increases tenfold and fructose becomes the dominant sugar in grapes.

When it comes to winemaking, the sugar level of the grapes is as vital as their acidity. It is, therefore, essential to pay attention to how two acids that the grape contributes to the edge of the wine evolve: tartaric and malic.

During the veraison phase, if the potassium level in the vine leaves increases, the malic acid in the grape also increases. From veraison until the grapes are harvested, if the potassium in the vine goes increases, the tartaric acid in the grapes decreases.

Before veraison, the concentration of sugars is low and the degree of acidity high. After veraison, sugar concentration and water level increase, leading to a reduction in sharpness.

Pazo Baión’s viticulture team’s mission is to ensure that the property’s grapes have an optimal balance in terms of sugars and acids. Therefore, during veraison and ripening, the work of supervising the evolution of the bunches is continuous.

Veraison alters grape composition

End of growth, beginning of ripening of the grapes

In addition to the change in colour and composition of the grapes, veraison brings with it the end of their development. After veraison, the berries no longer grow but ripen.

What do we mean by ripening? To address this question, we must differentiate between physiological and industrial ripening:

  • Physiological. This occurs once veraison is over and refers to the fact that the grape has finished its growth process and its seeds can now germinate. Thus, the nutrients the vine supplies to the grape are not directed to the seeds but to the pulp and skin.
  • Industrial. This concept is used to deal with grape ripening from the point of view of human consumption. And, as far as we are concerned, concerning the use of grapes to make wine. When is industrial ripening reached? When grape growers and winemakers determine that the grapes in a vineyard have reached optimum conditions for harvesting. For this, two issues must be taken into account:
    • Phenolic ripening. The key to this maturation lies in the aromatic composition of the grapes, linked to phenolic compounds.
    • Alcoholic ripening. This concept refers to the development of the grape pulp, and the aim is to ensure that the grape has the ideal sugar content for subsequent winemaking.

In light of what we have just said, we can continue with the parallelism between grapes and human beings. At the end of adolescence, we also stop growing (at least in height) and begin to mature physically, psychologically and emotionally. A complex maturation in which various aspects come into play.

The beginning of lignification: The vine shoot will give way to the vine shoot

Not only does veraison mark the beginning of grape ripening, but a similar process occurs in the plant itself, i.e. the vine: narrowing.

The shoots of the new harvest leave behind their green colour to take on a brownish hue. The herbaceous stems harden, becoming woody and impregnated with lignin. Hence, this process is also called lignification. In addition, they accumulate reserves to face the winter, ensuring the vine’s survival during the vegetative standstill.

The lignification or narrowing of the vine lasts longer than the ripening process of the grapes, and it lasts until the autumn leaves fall and the beginning of the well-deserved rest of this fascinating plant.

Therefore, veraison is not only a turning point in the life of the grape but is also of great relevance in terms of the vine’s life cycle.

Veraison triggers the countdown for the grape harvest

A brief but transcendental period

At this point, you may be wondering how long the veraison lasts. The answer to this question is twofold:

  • The veraison of a grape is a speedy process that takes only a couple of days.
  • However, the veraison of an entire vineyard takes place over a couple of weeks since not all grapes ripen at the same rate.

Veraison plays a crucial role in both alcoholic and phenolic ripening. In addition, during this phase, Pazo Baión’s viticulture team estimates the grape production to be achieved in the harvest. And the ripening phase is planned to prevent pests and diseases that can damage the grapes and effectively manage the vagaries of the weather.

The countdown to harvest begins

As the grapes begin to ripen, veraison undoubtedly becomes a phase that starts the countdown to the most critical moment of the year in a vineyard: the grape harvest. However, this does not mean that, depending on when the veraison takes place, a specific number of days can be established to start the harvest.

Both the moment when veraison takes place and the date on which the grapes reach optimum ripeness depends on fixed geographical factors (the location of the vineyard, the characteristics of the soil) but also on climatic aspects that can vary from one year to another (temperature, sun, rain, etc.). Depending on the date on which the veraison of a vineyard is completed, the viticulture team can establish not only a prediction of the future grape production but also the date on which the ripening of the grapes will be completed.

Be that as it may, it is clear that once veraison occurs, ripening begins, and sooner rather than later, the grapes will be ready to be harvested. Therefore, at Pazo Baión, the work in the vineyard increases, and controls of sugar, acidity or phenological composition are carried out with a clear goal: to achieve the best possible grape harvest to make our Albariño wines. Three Rías Baixas with unique personalities stands out for their long development in the mouth and superb aromatic compositions.

In short, veraison is one of the annual milestones of every vineyard. Two crucial weeks in which the grapes leave their growth behind and enter the ripening process that will ultimately define their characteristics and quality. The harvest is just around the corner, and all of us who are part of the Pazo Baión project are excited and ready to take care of every detail of the great grapes born from our long-lived vines.



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