Defining the nutritional drivers of yeast performance and matching yeast to must

Summary

Objectives:

  • Define yeast strain-specific performance parameters for at least 100 commercially available wine strains, enabling the matching of strain to must
  • Evaluate the yeast strain specific efficacy of fermentation additives in modulating the performance of yeast in wine fermentations

 

Background:

There are over 200 yeast strains available to the wine industry with limited detail about how they perform in different contexts, both in terms of fermentation kinetics and flavour outcomes. The aim of this proposal is to build a knowledge base on how these different yeast strains perform in different environments (i.e. grape juices of widely varying composition, which represents a range of wine styles) and how winemakers can optimize fermentation efficiency, and best mitigate against suboptimal (stuck and sluggish) fermentations while delivering wine styles to winemaker specifications.

Research approach:

The plan utilises a factorial approach to test yeast strains, nutrient levels and type on fermentation performance. The aim is to understand the impact of factors that can be controlled in a winery on the performance of at least 100 commercially available yeast strains.

This approach takes advantage of high throughput molecular biological methods and multifactorial design of experiments. Some preliminary work by the AWRI team identifying pH and potassium ion concentration as important to fermentation performance is promising and will be followed up.

Industry Benefit:

The knowledge generated by this project will enable winemakers to conduct efficient and reliable fermentations and produce quality wine to specification.