The production of ethylphenols in wine by yeasts of the genera Brettanomyces and Dekkera: A review

This work reviews the formation of ethylphenols (4-ethylphenol and 4-ethylguaiacol) from grape hydroxycinnamic acids in aging red wines by yeasts of the genera Brettanomyces and Dekkera. The physico-chemical factors that favour the growth of these undesirable yeasts, the techniques used to detect the presence of Brettanomyces/Dekkera species in wines, and the analytical techniques for monitoring the formation of volatile ethylphenols are all described. Finally, the advantages and disadvantages of the different options for controlling the growth of these yeasts are discussed.