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IVES 9 IVES Conference Series 9 Effects of soil and climate on wine style in the Breede River Valley of South Africa: Sauvignon blanc and Cabernet-Sauvignon

Effects of soil and climate on wine style in the Breede River Valley of South Africa: Sauvignon blanc and Cabernet-Sauvignon

Abstract

[English version]

Les effets du sol et du climat sur le style de vin ont été évalués pour des vignes irriguées à deux endroits différents de la vallée de la Breede, en Afrique du Sud. L’un des 2 endroits est cependant plus froid que l’autre, principalement en raison de températures nocturnes plus basses. Des mesures ont été faites pour le Sauvignon blanc et le Cabernet Sauvignon, aux deux localités. Deux formations pédologiques ont été identifiées au sein des deux vignobles de Sauvignon Blanc. A l’endroit le plus frais, le premier sol est sableux (4% d’argile), tandis que le second est plus argileux (21% argile). Par conséquent, la capacité de rétention d’eau (sur la profondeur racinaire) est de 62 mm/m pour le premier et de 157 mm/m pour le second. Une situation comparable existe au sein du vignoble de Sauvignon blanc à l’endroit plus chaud, avec une capacité de rétention d’eau allant de 60 mm/m pour le premier sol à 112 mm/m pour le deuxiéme. Une seule formation pédologique (terreau sableux contenant 18% d’argile) a été identifiée pour le Cabernet Sauvignon à l’endroit le plus frais. Par contre, à l’endroit le plus chaud, on trouve deux sols divergeants. Le premier contient seulement 2% d’argile, alors que le second en contient 37%, aboutissant à des structures de sol largement divergeantes.
Pour le Sauvignon blanc, l’intensité des arômes était plus élevée dans les vins de la localité la plus fraîche que celle dans les vins de la localité de la plus chaude, et ceci indépendemment du sol. A l’endroit le plus frais, les différents sols ont aussi produit des styles differents. En général, les vins issus du sol sableux sont dits “typiques” par comparaison à ceux issus du sol plus argileux. A l’endroit plus chaud, le style du Sauvignon blanc n’a pas été affecté par le sol. Dans le cas du Cabernet Sauvignon, l’intensité arômatique était comparable entre les vins issus de l’endroit plus frais et les vins issus du sol argileux de l’endroit le plus chaud. Cependant, les styles de vins étaient largement divergents, ainsi les vins de l’endroit le plus frais révélaient un caractère herbacé prononcé, alors que les baies dominaient pour le vin de la localité la plus chaude. A l’endroit le plus chaud, le style du Cabernet Sauvignon était aussi affecté par le sol, avec des notes de baies et une intensité arômatique plus faible pour les vins issus du sol sableux.
Les résultats indiquent que le style de vin de la vallée de la Breede n’est pas seulement affecté par le climat, mais aussi par la formation pédologique. L’effet du sol peut-être dimimuée où l’irrigation est scientifiquement programmée, mais pas entièrement éliminée.

The effects of soil and climate on wine style were evaluated for irrigated vineyards at two different localities in the Breede River Valley of South Africa. One locality was cooler than the other, largely on account of lower night temperatures. Measurements were done for Sauvignon blanc and Cabernet Sauvignon, at both localities. Two contrasting soil forms were identified within both Sauvignon blanc vineyards. At the cooler locality the first soil was sandy (4% clay), while the second was more clayey (21% clay). This resulted in a water holding capacity of 62 mm/m for the first, in comparison to 157 mm/m for the second. A comparable situation existed within the Sauvignon blanc vineyard at the warmer locality, with water holding capacity ranging from 66 mm/m to 112 mm/m for the two soils. Only one soil form (sandy loam, containing 18% clay) was identified for Cabernet Sauvignon at the cooler locality. At the warmer locality, however, two divergent soil forms occurred within the Cabernet Sauvignon vineyard. The first contained only 2% clay, in comparison to 37% for the second, resulting in widely divergent soil structures.
For Sauvignon blanc, aroma intensity was higher in wines from the cooler locality than in those from from the warmer locality, irrespective of soil form. At the cooler locality different soil forms also induced divergent styles. In general, wine from the sandy soil was regarded as more “typical”, in comparison to the one from the more clayey soil. At the warmer locality the style of Sauvignon blanc was not affected by soil form. In the case of Cabernet Sauvignon, aroma intensity was comparable for the wine from the cooler locality and the one from the clayey soil at the warmer locality. However, styles were widely divergent, with wine from the cooler locality exhibiting a pronounced grass character, in comparison to a berry character for the one from the warmer locality. At the warmer locality the style of Cabernet Sauvignon was also affected by soil form, with berry character and aroma intensity being lower in wine from the sandy soil.
Results indicated that the style of wines from Breede River Valley is not only affected by climate, but also by soil form. The effect of soil form can be diminished where irrigation is scientifically scheduled, but not entirely eliminated.

DOI:

Publication date: January 12, 2022

Issue: Terroir 2004

Type: Article

Authors

W.J. Conradie (1) and V. Bonnardot (2)

1) ARC Infruitec-Nietvoorbij, Private Bag X5026, 7599 Stellenbosch, Republic of South Africa
2) ARC Institute for Soil, Climate and Water, Private Bag X5026, 7599 Stellenbosch, Republic of South Africa

Contact the author

Keywords

Soil, climate, Breede River Valley, wine style, Sauvignon blanc, Cabernet-Sauvignon

Tags

IVES Conference Series | Terroir 2004

Citation

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