## 1 Introduction  
The use of non-_Saccharomyces_ yeasts in winemaking has been extensively assessed, as they may confer a series of advantages. Indeed, the modification of sensorial complexity, as well as the reduction of ethanol and biogenic amine content, through co-fermentation of _Saccharomyces cerevisiae_ with non-_Saccharomyces_ yeasts such as _Hanseniuspora vitane_, _H. vararum_, _Lachancea thermotolerans_, _Metschnikowia pulcherrima_, _Pichia fermentatus_, _Sarmerella bacillaris_, _Toruspora delbrueckii_, and _Wickerhamomyces anomalus_ has been reported [1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17]. In addition, their capacity to act as bioprotective cultures, and therefore lead to a reduction of SO\({}_{2}\) addition or even confer probiotic beetle benefits to the consumer, have also been considered [18; 19; 20; 21; 22; 23; 24; 25]. As a result, a series of non-_Saccharomyces_ yeasts are currently commercially available.  
Among the non-_Saccharomyces_ yeasts studied, _L. thermotolerans_ constitutes a very interesting alternative, as it may contribute to addressing the negative effects of climate change in winemaking. More specifically, global warming resulted in grape ripening acceleration, which in turn allowed for grape musts with lower acidity and higher carbo-hydrate concentration [26]; the first compromises wine stability, while the second results in wines with higher ethanol content. Both constitute significant problems for the wine industry [27]; therefore, the quest for tackling strategies is ongoing. _Lachancea thermotolerans_ may provide a feasible solution, as it has the ability to produce lactic acid through carbohydrate catabolism, increasing the acidity of the must and depriving carbon sources for ethanol production by _S. cerevisiae_[28]. Indeed, the fermentation by _L. thermotolerans_ and _S. cerevisiae_ of grape musts of many varieties, including Airen, Albarino, Babic, Blatina, Cabernet Sauvignon, Emir, Frankovka, Garganega, Mencia, Merlot, Muscat, Pinot Blanc, Plavac Mali, Riesling, Sangiovese, Sauvignon Blanc, Shiraz, Treixadura, and Trinjak, has highlighted the feasibility of this strategy, as well as the modification of sensorial perception of the wines produced [29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43].  
The _Vitis vinifera_ cv. Assyrtiko is indigenous to the island of Santorini, specifically adapted to its unique edapholimatic conditions. The PDO Santorini made by this variety is characterized by a dense structure, crisp acidity, and minerality. This distinctive character is at risk due to global warming. Indeed, a decrease in acidity and an increase in ethanol content would be detrimental to the unique sensorial qualities of PDO Santorini. Therefore, the need for approaches capable of addressing this issue is imperative. The aim of the present study was to sequentially ferment grape must of the Assyrtiko variety by _L. thermotolerans_ and three _S. cerevisiae_ strains and evaluate the effect on physicochemical parameters and sensorial perception. Especially regarding the latter, sensory evaluation was performed by two expert panels, one familiarized with the specific organoleptic features of this variety and one that was not accustomed to them.