Winemaking treatment – Eucalyptus leaves

This winemaking treatment simulated how the presence of eucalyptus leaves in harvested fruit can modulate the aroma and flavour of the resultant wine. This treatment was conducted purely as a demonstration and it should not be replicated.

Background

There is an abundance of anecdotal evidence reporting that wines made from grapes grown close to eucalypt trees can exhibit a ‘minty’, ‘fresh green’ or ‘eucalypt’ character. The compound responsible for this character in wines has been identified as the monoterpene compound 1,8-cineole (1,3,3-trimethyl-2-oxabicyclo-[2.2.2]octane) which is commonly known as ‘eucalyptol’ (Farina et al. 2005).

For some winemakers this character is a selling point and their red wines are known for their ‘eucalypt’ sensory properties. For others, however, eucalypt characters are something they prefer to avoid, or limit through effective management strategies. The AWRI’s research on eucalypt character in wine has focused on understanding the source of the character and providing options for winemakers to be able to modulate it.

Research

Capone et al. (2014) showed that the presence of eucalyptus leaves in harvested grapes is the major pathway for eucalyptus character (1,8 cineole) to enter wines. More recent work on the effect of certain species of trees used as wind breaks has identified that other types of tree material such as pine needles from radiata pines can also end up in grape bunches and have a sensory effect on wines (Capone et al. 2017).

Management of eucalypt character

Options to manage eucalypt character in wine include:

  • Harvesting fruit grown closest to eucalypt trees and fermenting it separately from the rest of the vineyard, leaving it available for blending with other wine as desired
  • Removing by hand any eucalypt leaves or woody material from the vines prior to harvest

Resources

Eucalyptol section of the AWRI’s wine flavours web page

AWRI fact sheet – Eucalyptus character in wine

Capone, D., Bey, L., Barker, A., Espinase Nandorfy, D., Williamson, P., Solomon, M., Francis, L. 2017 Trees and vines: can different types of local vegetation contribute to wine flavour? AWRI Tech Rev. 229: 7-10.

Capone, D.L., Leeuwen, K.V., Taylor, D.K., Jeffery, D.W., Pardon, K.H., Elsey, G.M., Sefton, M.A. 2011. Evolution and occurrence of 1,8-cineole (eucalyptol) in Australian wine. J. Agric. Food Chem. 59(3): 953–959.

Capone, D.L., Sefton, M.A., Jeffery, D.W., Francis, I.L. 2014. Terroir or terpenoid transformation: the origin of 1,8-cineole (eucalyptol) in wine. Hofmann, T.; Krautwurst, D.; Schieberle, P. (Eds.) Proceedings of the 10th Wartburg Symposium on Flavor Chemistry and Biology, Eisenach, Germany, 16-19 April, 2013. Freising, Germany; Deutsche Forschungsanstalt für Lebensmittelchemie: 130-136.

Capone, D.L., Jeffery, D.W., Sefton, M.A. 2012. Vineyard and fermentation studies to elucidate the origin of 1,8-cineole in Australian red wine. J. Agric. Food Chem. 60 (9): 2281–2287.

Farina, L., Boido, E., Carrau, F., Versini, G., Dellacassa, E. 2005. Terpene compounds as possible precursors of 1,8-cineole in red grapes and wines. J. Agric. Food Chem. 53(5): 1633-1636.

Lindh, K. 2009. Are wines affected by the proximity of vineyards to Eucalypt trees? Aust. N.Z. Grapegrower Winemaker (541): 56-57.