Our environment

Climate change has been studied for several decades now, and the conclusion from these observations is clear: there are profound changes taking place in our vineyards. These environmental pressures, as well as the societal evolution of consumer expectations, require winegrowers, winemakers and oenologists to adapt in a multidisciplinary way in order to provide increasingly complex solutions.

The decrease in the water balance of nearly 200 mm in 60 years (data: Saint-Emilion, see opposite) illustrates the increasingly dry summers.

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Evolution of the climatic water balance from 1952 to 2012 by modelling the climatic water balance calculated between April 1 and September 30 for the Saint-Emilion region. Water balance calculated according to Lebon et al. 2003; parametrization: RU = 0 mm without stomatal regulation).

As a result of temperature rise, grapevines develop earlier and consequently harvest dates are brought forward..

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Evolution of harvest dates in Châteauneuf du Pape between 1945 and 2013. Source: ONERC 2014.

The increasing number of climate-related incidents (heavy rainfall in spring, heat waves and water stress in summer) impact the physico-chemical composition of the grapes (polyphenol and aromatic precursor content, heterogeneous maturity, bitterness or structural imbalance) which is reflected in the wines (hardness, bitterness, color instability or masking of aromatic intensity).

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Evolution of the expected alcoholic strength, acidity and pH of grape must in Languedoc vineyards between 1984 and 2013.

The wines produced are increasingly imbalanced. In effect, there is higher potential alcohol content and pH accompanied by lower acidity (data: Languedoc, see opposite).

The result of 5 years of research

One of the first levers for responding to oenological or market expectations apply to vineyards. This observation led to a study in 2014 that continued over the following 5 vintages . Significant results were obtained in terms of analysis and sensory properties by assessing different protocols in the vineyard and in the cellar, based on organic nutrition rich in amino acids.

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Solutions for the vineyard

One of the first actions in viticulture and oenology is the nutrition of the grapevine. It plays a part in the effects of cultivation and climate and, together with the water regime, is one of the most important determining factors in yield balance, berry formation, the composition of the must, and ultimately the quality and profile of the wine.

Precision programs

An agronomic precision program was set up and applied on a plot of Syrah located in the Crest Petit area (66) combining the climate and soil constraints that this grape variety is sensitive to. The plot is divided into two parts: the control and the nutrition and stimulation program (NSP).

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Plot of Syrah in Crest Petit - North/South slope - Soil of limestone garrigue clearing with low-fertility outcropping substratum, a crushed limestone soil with very low fine earth content and high ph (8.2), at risk of iron chlorosis.

Yield evolution in kg/ha in Crest Petit Syrah control and NSP plots, from 2011 to 2019 (2019 vintage, NSP zone: + 35%; average 2011-2019, NSP zone: + 22%).

Monitoring of agronomic indicators

Agronomic production measurements were carried out since 2011 at grape picking time. These measurements are agronomic indicators regarding the production of both parts of the plot: the control and the nutrition and stimulation program (NSP). The 2019 vintage showed an average yield increase of 35%. This increase was 22% over the entire study.

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Solutions for the cellar

In order to measure the impact of the protocols implemented in the vineyard regarding the balance of the musts and the organoleptic characteristics of the wines, two vinification protocols were compared: one protocol using classic nutrition (classic vinification) with a so-called neutral yeast strain; and another protocol using complex nutrition (organic vinification) with a so-called aroma-revealing yeast strain. These vinifications were carried out at the experimental cellar of the Sofralab®Group's oenological campus located in Montagnac (34).

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The results of the analyses of musts from the control and NSP plots showed that there was no significant difference in the chemical parameters studied (volatile acidity, alcohol content, total acidity, pH), thus confirming that the oenological qualities of the musts are preserved in spite of increases in yield.

Analysis results

The composition of volatile thiol and ester-related compounds was also analyzed in the wines after bottling. The two wines made from the musts of the NSP plot (classic vinification and organic vinification) had higher average concentrations of volatile thiol-related compounds than those observed in the wine from the control plot. This increase is even more pronounced between the control and the wine vinified with the aroma-revealing yeast strain.

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Average concentrations of volatile thiol-related compounds (ng/l) in wines after bottling, observed over 2015 to 2018 vintages.

Star chart of the averages in the 2015 to 2018 vintages during the tastings of the 3 modalities: classic vinification control, NSP + classic vinification, and NSP + organic vinification.

Sensory analysis

Tasting results show that the wines from the NSP plots got higher overall scores. They are noted as fruitier, more intense and with a citrus-like thiol profile. A synergy was observed between the organic nutrition and stimulation program in the vineyard and organic nutrition in the cellar.

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79 Avenue A.A. Thévenet
CS 11031 - 51530 Magenta
Tel.: +33 3 26 51 29 30

Sofralab-Groupe-logo

79 Avenue A.A. Thévenet
CS 11031 - 51530 Magenta
Tel.: +33 3 26 51 29 30

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