The traditional “Ban des Vendanges”, the official start date determined by the town authorities, is a formality that has become part of Bordeaux’s rich history. Today, it is up to the grower to decide the best time to pick the grapes, depending on the specific character of his vineyard. In all cases, optimum grape ripeness in each vineyard parcel remains the key driver. But do you know how the actual picking date is determined?
To shed some light on this crucial step, the Dourthe team provided a sneak preview in the vineyard:
What is grape ripeness?
A grape is deemed ready to be picked when it reaches optimum ripeness. It is therefore vital to monitor ripeness levels in the grapes, while bearing in mind several criteria:
– Technical ripeness
Technical ripeness, or sugar ripeness, is the amount of sugar and acidity in the grapes. The riper the grape, the higher the sugar content, and in turn, the lower the acidity. When the sugar content is at its peak, the grapes have reached technical ripeness.
– Phenolic ripeness
Here we check the ripeness of the fruit, the pulp, the skins and the pips. Over time, the stalk turns brown, the grape skins become thinner and the pips dry out. The skins and pips contain tannins and anthocyanins (colouring agents), which impart structure to the wine. The riper the grapes, the easier it will be to extract these compounds and the greater the quality. As to the best time to pick: not too soon and not too late!
– Aromatic ripeness
Aromatic ripeness is when the grapes present the greatest concentration of aromas. The aromatic compounds develop throughout ripening, which is a process greatly affected by weather; hot, sunny days and cool nights produce generous quantities of high-quality aromatic compounds.
The grower will look for the ideal balance of all these different elements, in each vineyard parcel, in a bid to harvest the best quality grapes possible.
How can you tell when a grape is ripe?
By analysis and tasting.
A few days before the scheduled harvesting date, the teams at each chateau will take a random sample of around 400 grapes across each parcel or sub-parcel.
Half the sample is sent to the laboratory to analyse sugar and acidity levels. While analysis is an important step, it needs to be backed up by tasting. The technical team then taste the other half of the sample. We taste 3 or 4 grapes, crushing the skins and pips in the mouth to analyse the taste, texture and tannic structure, and estimate the potential ripeness of each parcel.
This empirical method not only requires some getting used to, but essentially an excellent knowledge of the vineyard. In the Dourthe vineyards, tasting the grapes is a vital element that will help determine picking dates. By combining all the results from the laboratory and tastings, the weather forecast and the grape variety, every chateau can now determine the ideal harvest date for each parcel or micro-parcel.
This is very much a joint decision that marks the start of a long journey that could last a few days or a matter of weeks, depending on the size of the vineyard.