Last week we talked about the unusual weather conditions of the winter and spring in Bordeaux during the last growing season. Winegrowers faced one of the mildest and wettest winter, then a spring full of surprises but promising of a successful season. What are the key factors in the summer and the fall that pushed this vintage towards its wonderful results? Here’s the second part of our analysis of the Bordeaux 2016 vintage.
A hot and dry summer
The summer period reversed the favorable trend. The month of July was the driest of the last 10 vintages with less than 10mm of rainfall. The month of August and the first half of September, in addition to being dry, brought maximum temperatures above seasonal averages. This caused moderate to strong water deficits post-veraison. Water deficit severity varied according to the terroirs. It was not until September 13 that rains finally relieved the water deficit. Numerous studies (Herrera et al., 2015, Kyraleou et al., 2015 etc.) show that water deficit boosts the accumulation of anthocyanins in the berries as log as it stays moderate and at the right time of berry development.
The high temperatures during the first phase of maturation accelerated sugar accumulation and malic degradation in the berries, decoupling technological and phenolic maturity. According to an article published in 2016 by Casassa, high temperatures also increase the extraction of tannins. Finally, numerous studies show a positive impact of light on skin tannins and anthocyanins (Blankaert, 2015).
Delayed harvest and elegant wine tannins
From the second half of September, temperatures decreased significantly. The cooler conditions enhanced the preservation of berry aromatic quality and pushed back the maturity process. The delayed harvest dates made it possible to decrease tannins molecular mass and thus their activity (Campbell, 2016). (NB : Tannins Activity is a new physical concept. It aims at quantifying the potential interaction between tannins and salivary proteins). These conditions were propitious to the development of wines with more elegant tannins.
In conclusion, after a complicated start of the season, the hot and dry summer followed by cooler climatic conditions facilitated the development of an elegant maturation profile, and thus produced balanced wines (measured by alcoholic concentration versus acidity) that are rich in color and tannins.
Read the original article in French here.
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