title. The influence of storage temperature on yeast growth and 4-EP production.

date. 2012

city. Lisbon, Portugal

keywords. Dekkera bruxullensis, Brett, 4-EP, temperature

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Worked with Professor Malfeito Ferreira to determine the lowest temperature degree for Dekkera bruxullensis (a.k.a Brett) at UTL-ISA (Universidade Tecnico de Lisboa- Instituto Superior de Agronomia)

 

Some people consider that Brett is a fault, for some it ads “terroir” (sense of place) to the wines. In artistic winemaking “terroir” is very important thing to have add an unique characteristic in wines. But to have too much Brett flavor may ruin your wine. With this project, I worked with world renowned wine microbiologist Prof. Malfeito Ferreira to obtain lowest temperature that Brett can grow. He is the person that invented selective microbiological media ( DBDM - Dekkera / Brettanomyces Differential Medium)for Dekkera bruxullensis.  

 

We started a project that called the influence of storage temperature on yeast growth and 4-EP production. 4-EP (4-Ethyl-phenol) is a spoilage yeast that can produced by Dekkera bruxullensis. Previously it was declared by  Rayne and Eggers (2007) that it can grow at 10ºC. We observed that; The delay of cell growth in wine induced by low temperature may be used as a tool to prevent the horse sweat taint. In fact, lower 4-EP production rates give more opportunity for the winemaker to use other preventing measures like filtration, pasteurization or sulphur dioxide addition.  However, it should be kept in mind that our results showed that relatively low temperatures, like 10ºC, may not be enough to efficiently delay the increase in 4-EP production. We did discovered that Brett. May grow in lower temperatures like 3ºC.

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The results shown on the right:

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