Terroir 2020 banner
IVES 9 IVES Conference Series 9 Have the best Bordeaux wines been drunk already? A reflection on the transient nature of terroir, using case study Australia

Have the best Bordeaux wines been drunk already? A reflection on the transient nature of terroir, using case study Australia

Abstract

Aim:  The aim of this paper is to demonstrate that the meaning of terroir should be regarded as transient. This is because climate, one of the principal components of terroir, is changing with time, and can no longer be assumed to be constant with fluctuations about a mean. This is due to the climate crisis.

Methods and Results: The paper reviewed a very recent climate modelling study of Australian grape growing regions (GI’s) especially for temperature. It included Mean Growing Season Temperatures (MSGT) for the present period (1997-2017) and two in the future, (2041-2061) and (2081-2100). The results were in line with several previous projections indicating warming and drying trends over the period. Present hot inland regions will be the most affected. Literature references indicated similar trends elsewhere in the world including traditional vineyard regions of Europe.

Conclusions: 

Results of the climate modelling for Australia and the rest of the world suggest the need for adaptive responses as the terroir changes. This will require changes to variety or of the region. The transition will be easier for presently cool regions than for presently hot ones, as more potential varieties are available. Some currently hot regions may become unsuitable for wine production. There is evidence that the optimum temperature conditions for present varieties in regions like Bordeaux have already been surpassed by climate change.

Significance and Impact of the Study: There is limited evidence to date that global wine firms recognise the scale of this problem and are planning to adapt. A good outcome would be that the world wine map might be redrawn, to feature some new regions and new varieties in existing regions. A bad outcome would be associated with failure to acknowledge or address the impending crisis.

DOI:

Publication date: March 25, 2021

Issue: Terroir 2020

Type: Article

Authors

Richard Smart*

Smart Viticulture, Greenvale, Victoria, Australia

Contact the author

Keywords

Climate change, terroir, temperature

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

GRAPE SPIRITS FOR PORT WINE PRODUCTION: SCREENING THEIR AROMA PROFILE

Port is a fortified wine, produced from grapes grown in the demarcated Douro region. The fortification process consists in the addition of a grape spirit (77% v/v) to the fermenting juice for fermentation interruption, resulting in remaining residual sugars in the wine and increased alcohol content (19-22%). The approval of grape spirits follows the Appellation (D.O. Port wine) rules1 and it is currently carried out based on analytical control and on sensory evaluation done by the public Institute that upholds the control of the quality of Douro Appellation wines. However, the producers of Port wines would like to have more information about quality markers of grape spirits.

Using combinations of recombinant pectinases to elucidate the deconstruction of the polysaccharide‐rich grape cell wall during winemaking

The effectiveness of enzyme-mediated maceration processes in red winemaking relies on a clear picture of the target (berry cell wall structure) to achieve the optimum combination of specific enzymes to be used. However, we lack the information on both essential factors of the reaction (i.e. specific activities in commercial enzyme preparation and the cell wall structure of berry tissue). In this study, the different combinations of pure recombinant enzymes and the recently validated high throughput cell wall profiling tools were applied to extend our knowledge on the grape berry cell wall polymeric deconstruction during the winemaking following a combinatorial enzyme treatment design.

Cover crops under-vine impact on grapevine performance and vineyard soil microorganisms is highly affected by edaphoclimatic conditions at a regional scale 

Soil management through cover crops can influence the cycle of nutrients, promote water infiltration, decrease erosion, and enhance the soil microbiota biodiversity, improving the grapevine performance. However, the area under the vines tends to be left bare by applying herbicides or tillage to avoid competition with the crop in semi-arid climates. Use of covers under-vine might be an alternative to these practices aiming at grapevine quality and soil health improvement. The aim of this research was to study the implications of soil management under the vines (cultivation and cover crops) on growth, yield, berry composition and soil microbial communities. A cover crop composed by a mixture of legumes was sown and compared with a control (cultivation), which includes frequent tillage to keep the soil bare, in three areas characterized by different edaphoclimatic conditions in the region of Navarra.

Impact of deficit irrigation strategies on terpene concentration in Gewürztraminer grapes

Deficit irrigation is a viticultural practice often applied to improve the phenolic composition of red grapes and wines. However, the impact of this practice on grape terpenes – key aromatics for several grapes and wines – remains largely unknown. This study investigated the impact of deficit irrigation strategies on free and glycosylated terpenes in Gewürztraminer grapes. In a field study conducted in Oliver, BC, in 2016, 2017, and 2018, deficit irrigation regimes were applied to Gewürztraminer vines at different developmental stages (pre-veraison = Early Deficit, ED; post-veraison = Late Deficit, LD; throughout the season = Prolonged Deficit, PD). A well-irrigated control (CN) treatment was also established.

Effects of severe shoot trimming at different phenological stages on the composition of Merlot grapes

High concentration of sugars in grapes and alcohols in wines is one of the consequences of climate change on viticulture production in several wine regions. One of the options to alleviate this potential problem is to perform severe shoot trimming of the vines to limit the production of carbohydrates. Two different studies were performed in order to investigate the effects of severe shoot trimming on the composition of Merlot grapes; in a first study severe shoot trimming was performed at three different phenological stages (at berry set, at the beginning of veraison and at the end of veraison), while in a second study two trimming treatments (standard shoot trimming and severe shoot trimming performed at the end of veraison) were combined with two shoot densities in order to evaluate the relative impact of these treatments on Merlot grape composition.