Influencing wine style through management of oxygen during winemaking

Summary

Objectives

  • How much oxygen exposure of juice occurs during production and what is its impact on wine composition, flavour and style?
  • What is the impact of oxygen during primary fermentation on subsequent malolactic fermentation efficiency?
  • What is the best way to manage oxygen exposure?

Background

Effective management of oxygen during winemaking can help create diverse styles, attractive to a range of different consumers. There is a good understanding of the impact of oxygen on wine quality after fermentation, at bottling and during subsequent bottle storage. However, there is opportunity for further effective manipulation of wine style through management of oxygen exposure during juice preparation, by the controlled addition of oxygen at this stage.

There is preliminary evidence that controlled oxygen exposure during fermentation can influence flavour. This is over and above using oxygen to ensure fermentations don’t stick. The impact of oxygen during primary fermentation on subsequent malolactic fermentation efficiency is also an area that requires further investigation.

Research approach

This project will use laboratory-scale fermentation studies to scope and define parameters for oxygen use, and winery-scale fermentations to evaluate style and sensory profiles of wines that have been made with different oxygen regimes, from reductive to highly oxidative.

A second component of the project will investigate the effects of oxygen use during alcoholic fermentation on subsequent malolactic fermentation. This component will be performed in collaboration with AWR 1303 through the inoculation of Oenococcus oeni into oxygen treated ferments and monitoring of malic acid consumption using quantitative HPLC analysis.

Industry benefit

The knowledge and tools generated in this project will provide winemakers with more options to produce diverse and market-appropriate styles, for example ‘early release’ styles or styles with different texture and aroma profiles.