The wine yeast Saccharomyces cerevisiae experiences a range of stress conditions during wine fermentation. These stresses include osmotic stress, hypoxia, nutrient starvation, cold stress and increasing ethanol stress as fermentable sugars are converted to ethanol. These various stresses affect the functionality of the plasma membrane, cell wall and subsequently the yeast’s efficiency during fermentation. Etp1, a poorly characterized protein has been shown to have several different fermentation related phenotypes; it is needed for the turnover of the hexose transporter Hxt3 upon a shift from glucose to ethanol, and the transcriptional activation of the stress response genes HSP12 and HSP26 under ethanol stress. The molecular function of Etp1 during fermentation is not understood. This research aims to understand the molecular mechanism of Etp1 function and its involvement in Chardonnay fermentation using the S. cerevisiae M2 wine yeast strain.