Wort fermentability is an important parameter for successful beer fermentation. Besides the obvious economic disadvantages for breweries, incomplete sugar utilization could result in a beer with a higher risk for contamination by spoilage microorganisms [16]. In the present study, the effectiveness of proteases for sig- nificantly stimulating fermentation was observed at 12 days of fermentation for 20 ◦ P and 22 days for 24 ◦ P (Fig. 3) (p < 0.05). It was in accordance with the higher FAN level and the higher num- ber of suspension yeast cells in the later stages of fermentation. In high gravity worts (20 ◦ P), the highest wort fermentability, 85% was achieved for the fermentations with Flavorzyme supplementation, followed by the fermentations with Protamex (83%) and Neutrase (79%) supplementation. It has been demonstrated that higher wort gravity increased the magnitude of the stress (increased osmotic potential and ethanol toxicity, and reduced nutrient availability) to which the cell was subjected and resulted in lower fermentation rates [1].