Non- Saccharomyces  yeast plays an important role in the initial stages of a wild ferment, as they are found in higher abundance in the vineyard than  Saccharomyces cerevisiae . As such, there has been a focus in recent years to isolate these yeast species and characterize their effect on wine fermentation and subsequent aroma. This effect on wine aroma is often species and strain dependent, as the enzymatic profile of each yeast will determine which aroma compounds are formed as secondary metabolites. Semi-fermentative yeast, such as  Hanseniaspora  spp.,  Candida  spp. and  Metschnikowia pulcherrima , are commonly in high abundance in fresh grape must and have diverse enzymatic profiles, however they show a weak tolerance to ethanol, limiting their impact to the initial stages of fermentation. Fully fermentative non- Saccharomyces  yeast, characterized by high ethanol tolerance, are often found at low abundance in fresh grape must, similar to  Saccharomyces cerevisiae . Their ability to influence the aroma profile of wine remains high, however, due to their presence into the final stages of fermentation. Some fermentative yeasts also have unique oenological properties, such as  Lanchancea thermotolerans  and  Schizosaccharomyces pombe , highlighting the potential of these yeast as inoculants for specific wine styles.