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The quality factor for the consumer that traditional opaque beer is drinkable is the continuous fermentation and appearance of foam. The use of commercial enzymes at pitching time for continuous release of fermentable sugars, continuous fermentation, and subsequent increase of the shelf life of opaque beer was investigated. The standard split-sour, double-cook brewing process was followed. Mashing temperature was modified and malt wort enzymes were inactivated before fermentation. Thermostable α-amylase was added at a dosage of 18 KNU-S/kg grist in order to facilitate the brewing process. Glucosidase dosages of 2.0 and 4.0 AGU/L at pitching were considered. Alcohol and sugar content were measured in order to follow the shelf life. There was a continuous decrease of total sugars, DP-3, and DP-4+, as compared to the reference sample, during fermentation. Consequently, fermentable sugars were provided throughout the fermentation. At a glucosidase dosage of 4.0 AGU/L, an increase of the alcohol content up to a value of 3.7% abv. at 13 days (the time span considered in this study) was recorded. Out of this study, the proposed procedure has the potential to extend the shelf life of opaque beer by 8–11 days to 13 days. Keywords: Exogenous enzymes, Opaque beer, Shelf life, Sorghum
