1. Introduction of the Brettanomyces Impact Wheel
Lucy Joseph
Department of Viticulture and Enology
U.C. Davis

2. Introduction
Brettanomyces is considered to be the primary spoilage yeast in finished wine
However, many consumers and critics like the complexity that is derived from Brett growth in wine
What accounts for that complexity?

3. Compounds Produced by Brett in Wine
Signature spoilage compounds - ethyl phenols, vinyl phenols
Other spoilage compounds – acetic acid, ethyl acetate, fatty acid, carboxylic acid
Compounds that are positive – Esters, higher alcohols, terpenes

4. Strain Collection

5. Initial Screen Defined medium was used Supplemented with amino acids
All strains will make 4EP and 4EG with coumaric and ferulic acids

6. Initial Screen

7. Correlation of Descriptors with Intensity and Like/Dislike scores

8. Selection for Test in Wine
Descriptors, intensity, and likability used to score strains
Out of the initial 83 that were successfully screened in the initial screen, 17 were chosen as “positive” and 5 as “negative”

9. Positive and Negative Perception

10. Summary of Aroma for Strains Tested in Wine

11. SPME-GCMS These strains were also screened chemically
Used defined medium supplemented with
Aromatic amino acids
Cinnamic acids and aromatic amino acids
Goal was to identify strains that produced low negative characters

12. Strains – Aroma Compounds

13. Acknowledgements
Beth Albino
Bisson Lab