During alcoholic fermentation, yeast cells are progressively exposed to a very stressful environment due to the strong decrease of external pH and to the rising accumulation of ethanol in the external medium. Such environment induces progressively a slow decrease of cell viability, related to alterations of the cellular plasma membrane, which in very stressful conditions (nutrient depletion, low and high fermentation temperatures, for example) may lead to a sudden fall of cellular viability towards zero before alcoholic fermentation was complete. Such sluggish or stuck fermentations represent a great risk for winemakers since residual sugars in finished wines represent always certain microbiological and sensory instabilities. Since now about 25 years, the use of Active Dry Yeasts (ADY) as starters for winemaking allowed more reproducible alcoholic fermentations. However, their use did not overcome the risks of cellular viability losses when stressful environmental conditions are encountered. Addition of several nutrients (nitrogen, vitamins or oxygen) during fermentation may only partially protect yeast cells from such stressful conditions. Today, recent research results obtained on the physiology of yeasts during ADY rehydration give a challenging opportunity to design new products for the improvement of alcoholic fermentation in extreme conditions. The aim of the present conference is to give an overview of such results with a peculiar emphasis on their potential impact for winemakers.