## 1 Introduction  
For thousands of years, _Saccharomyces_ have been used by humans to produce fermented foods and beverages. Over the past decades, modern industrial winemaking has been based on the use of starter cultures of specialized and selected wine strains [1, 2]. Although the use of selected _Saccharomyces cerevisiae_ strains guarantees the control of fermentation, their widespread utilization can lead to a double consequence: the reduction of indigenous microbiota and the standardization of the wine aroma complexity, which is often linked to the involvement of native yeasts during the fermentation [3, 4, 5, 6, 7, 8].  
To overcome this trend, in recent decades, several winemakers have carried out spontaneous fermentation's exploiting indigenous yeasts coming from the vineyard or vinery equipment, with the aim to improve the analytical and aroma complexity and to give peculiar and recognizable flavors to the final wine [5, 9]. Indeed, recent studies demonstrated that specific grape varieties and the climate of a specific geographical area seem to influence the yeast community [10, 11, 12, 13, 14], indicating a variation of the microbial community of grapes in the function of regional distribution [15, 16, 17, 18, 19]. Recently, the correlation between the regional microbial community and the organoletic characteristics of wine has attracted growing attention [11, 20, 21]. The understanding of the mechanisms and factors that stabilize a specific epiphyble population in different grape varieties could be useful to establish a correlation with the influence of regional yeast microbiota in the analytical and aromatic characters of the final wine [11, 20, 21, 22]. However, controversies exist regarding the origin of native _S. cerevisiae_ strains. Several studies showed that the direct isolation of _S. cerevisiae_ strains in undamaged grapes and vineyards is very difficult [8, 23, 24, 25]. [PERSON] and [PERSON] [26] already showed that damaged grapes represent a depository habitat of _Saccharomyces_ yeasts. Several authors claimed that the detection of _S. cerevisiae_ strains in both vineyards and grapes, is obtained only after grape autoenrichment, due to their deficiency [27; 28; 29]. On the other hand, it is well known that _S. cerevisiae_ is widely spread in the winery environment and on equipment [30; 31; 32; 33]. The ability of _S. cerevisiae_ to dominate the fermentation process and other competitive advantages allow this species to survive and reproduce in stressful winery conditions.  
Knowledge of the occurrence of _S. cerevisiae_ and their colonization on grapes or in the cellar could be of help to preserve the indigenous population and to establish a possible correlation between them and the final wine quality.  
In the present study, the occurrence, and the persistence of native _S. cerevisiae_ in the vineyard and winery and in uninoculated wine fermentation was investigated. The organic winery under investigation, which began its activity in 2013 and had never used commercial starter strains, represents an ideal winemaking environment to investigate the dynamics of grape-related and/or winery-related native yeast populations. Within the population of _Saccharomyces_ strains, the dominant biotypes were evaluated and characterized for their oenological aptitude and aromatic profile with the aim to use these native strains as starter cultures.