Effects of Operating Conditions during Low-Alcohol Beer Production by Osmotic Distillation

Osmotic distillation (OD) is a membrane technology most commonly used for liquid concentration, but recently there has been an increased interest in ethanol removal from alcoholic beverages. The aim of this paper is to investigate the effect of the variation of some operating conditions (temperature, flow rate, type and amount of stripping solution), specifically in regard to the effect on quality and sensory properties of the dealcoholized beers. The results indicated that temperature and flow rate variation showed no significant effect, whereas stripping solution variation had substantial effects mainly in terms of the ethanol removed. A cost appraisal showed that the operating costs were high mainly because of the cost of the stripping water. However, it is important to consider the final stripping solution, which is slightly alcoholic and enriched in flavor. For this reason, it could be reused in the manufacture of beverages, for instance as high gravity beer dilution water.