A simple cultural method for the presumptive detection of the yeasts Brettanomyces/Dekkera in wines

Aims: The development of a simple and reliable procedure, compatible with routine use in wineries, for the presumptive detection of Brettanomyces/Dekkera from wine and wine-environment samples. Methods and Results: The method of detection of these yeasts employs a selective enrichment medium. The medium contains glucose (10 g 1^-1) as carbon and energy source, cycloheximide (20 mg 1^-1) to prevent growth of Saccharomyces, chloramphenicol (200 mg 1^-1) to prevent growth of bacteria and p-coumaric acid (20 mg 1^-1) as the precursor for the production of 4-ethyl-phenol. After the inoculation with wine, the medium is monitored by visual inspection of turbidity and by periodic olfactive analysis. Contaminated wines will develop visible turbidity in the medium and will produce the 4-ethyl-phenol off-odour, which can be easily detected by smelling. Conclusions: A selective enrichment liquid medium was developed to differentially promote the growth and activity of Brettanomyces/Dekkera. The method is simple to execute, employing a simple-to-prepare medium and a periodic olfactive detection. Significance and Impact of the Study: The characteristics of the procedure make it particularly applicable in a wine-making environment thus presenting important advantages to the wine industry.