Wine quality in a changing climate

The effect of heat stress on grape composition

Supervisors: Dr Chris Soar (08 8303 8649) Dr Paul Boss (08 8303 8614) Dr Brian Loveys (08 8303 8615)
Location: Adelaide
Financial support: To be confirmed

This is a joint project between the South Australian Research & Development Institute and CSIRO Plant Industry.

Climate change has been identified as a significant risk to consistency of quality in
global wine production. Increased climate variability, in particular increased occurrence of extreme temperatures and shifting rainfall patterns in wine grape producing regions may result in increased occurrence of heat and water stress on grape bunches. Several aspects of grape berry ripening and juice composition such as colour, acidity and the presence and composition of flavour and aroma compounds are known to be influenced by temperature and stress. Thus predictions for climate change within this century have the potential to substantially shift regions of premium wine production. In addition increased climate variability may result in greater inconsistency in year to year vintage quality at the regional and vineyard level.

At present there is a gap in knowledge as to the specific effects of extreme heat stress on wine composition. This deficiency means it is difficult to model the likely effects of climate change on wine quality and therefore devise management strategies to offset the potential risks.

Aims: Specifically this project will analyse the effect of short-duration high-temperature treatments on the formation of colour, flavour and aroma compounds in grapes and wine. This will add to our general understanding of how heat stress at the vine and bunch levels alter wine composition but will also feed into modelling studies that will help predict the risks that climate change poses to wine quality consistency. This project will interact closely with existing projects looking at the effects of extreme heat stress on grapevine performance.

Experimental approach: The project will utilise gas chromatography, mass spectrometry, HPLC and various analytical protocols to analyse aspects of grape and wine composition from heat stressed material sourced from vineyard, glasshouse and growth chamber experiments.

References:

• Jones GV, White MA, Cooper OR and Storchmann K (2005) Climate change and global wine quality. Climate Change 73: 319-343.
• Gladstones J (1992) Viticulture and Environment (Winetitles: Adelaide).
• White MA, Diffenbaugh NS, Jones GV, Pal JS and Giorgi F (2006) Extreme heat reduces and shifts United States premium wine production in the 21st century. PNAS 103: 11217-11222.