Addressing production challenges through the management of wine non-volatiles
Summary
Objective
This project will provide knowledge to support producers to achieve optimal extraction, retention and stability of non-volatile compounds in wine, while minimising production inefficiencies. There is potential for the project to reduce production costs and improve value through:
- Developing management techniques to optimise non-volatile extraction and prevent losses.
- Providing producers with alternative processes or fining agents which will enable them to better tailor their winemaking to meet multiple market sectors (e.g. vegan fining agents).
- Delivering improved membrane processing techniques and/or applications.
- Improving production efficiency by generating knowledge on how to better predict and manage the critical points at which non-volatile composition may cause instabilities.
- Building resilience in the wine sector by developing a core capability in nanotechnology and interfacial science to address current and future production challenges.
Background
Non-volatile compounds such as anthocyanins, tannins, polysaccharides, proteins, amino acids and organic acids are present in wine at high concentrations relative to other components. Adequate extraction and retention of non-volatile compounds are critical to wine quality (colour, texture). However, due to both their larger size and tendency to interact, non-volatile compounds cause problems in wine processing, like haze formation, precipitation, crystallisation and adsorption.
The project aims to tackle these challenges through three focus areas:
- Determining the processing levers which significantly shift the profile of non-volatile molecules in wine. An aim will be to characterise the mechanism by which ionised red wine pigments limit potassium bitartrate (KHT) crystallisation, to better control pigment composition, and hence red wine cold stability as pigment profiles become modified during wine processing and ageing. This work aims to support producers in warm regions where red wines typically exhibit low colour and high pH.
- Deploying state-of-the-art techniques to characterise wine colloids to define, and thereby strategically manage non-volatile interactions at critical points in the winemaking process. Examples of this would include controlling colloidal instabilities such as pigment, protein or KHT precipitation, or adsorption to surfaces (e.g. membrane fouling).
- Characterising and modifying surfaces/adsorbents able to modulate wine non-volatile composition in a targeted way (e.g. protein or tannin removal), aiming to develop improved processing tools, such as alternative fining agents, antifouling surfaces or packaging.
The fundamental knowledge generated will form the basis to design and implement improved techniques or processes to manage non-volatile compounds in winemaking.
This project builds on findings from previous research in AWRI 1701-3.1.4 (Managing wine extraction, retention, clarity and stability for defined styles and efficient production).