This project will investigate the impacts of oxygen exposure at crushing or during fermentation on fermentation efficiency and wine style.
Research conducted to date indicates that red and white fermentation systems respond distinctly differently to the addition of oxygen. Oxygen addition to white wine fermentations primarily reduces fermentation duration with limited sensory impacts. In contrast, oxygen additions to red wine fermentations cause relatively little improvement in performance, but can have substantial impacts on the chemical and sensory attributes of the wine.
Practical knowledge about methods for appropriate delivery of oxygen to fermentations, and dose, remains a limiting factor affecting the uptake of oxygen use during winemaking by the sector. This project will explore different approaches to oxygen delivery and developing knowledge and advice to pass on to winemakers.
Wines with known oxygen exposure will be monitored as they age, to assess oxygen-related chemical changes that occur after fermentation. Factors that modulate these changes (e.g. metals, pH, time and duration of oxygen exposure) are critical to delivering the best quality product to the market and the consumer.
Shiraz and Chardonnay have been the primary varieties investigated to date, and it is of value to establish whether the impacts observed with these varieties also translate to other varieties and styles such as Merlot, Cabernet Sauvignon, rosé, sparkling wines, alternative varieties and spontaneous fermentations.
New knowledge on the impact on wine style and sensory properties of key oxygen modulated compounds and practical advice and extension materials about methods to introduce oxygen and the impacts of timing and dose of addition.