Hazy wine – using yeast to make it crystal clear Thulile Ndlovu, Benoit Divol, Florian F. Bauer # Institute for Wine Biotechnology, Faculty of AgriSciences, Stellenbosch University, Stellenbosch, South Africa # Phone: Fax:

What is haze What is haze? Causes of wine haze Bacterial contamination Tartrate crystals Polysaccharides √ Protein instability

Clarifying agents used in industry

Mannoproteins

Reduction of astringency Reduces haze Foam quality Retention of aroma compounds Mouth feel Reduces wine haze Improves mouth feel

Our study

Materials and Methods

Haze production in fermented grape juice  Wines fermented with strains 4 and 5 clearly showed reduced haze formation

Total protein staining of deglycosylated protein extracted from fermented MS KDa 55KDa 43KDa 34KDa Strain1 Strain2Strain4Strain5Strain3 Strains 4 and 5 have a lower band protein than the other strains

Types of protein released Cell wall

Summary of results and conclusion Differences in haze protection capacities Proteins highly expressed in Strain 4 Haze protection factor genes Further characterize the released proteins Use of Strain 4 in wine making Yeast breeding purposes

Acknowledgements  Prof F. Bauer and S. Hohmann  Dr B. Divol

Thank you