ORIGINAL PAPER Influence of temperature on continuous high gravity brewing with yeasts immobilized on spent grains

Abstract Flavor compounds ’ formation and fermentative parameters of continuous high gravity brewing with yeasts immobilized on spent grains were evaluated at three dif-ferent temperatures (7, 10 and 15 C). The assays were performed in a bubble column reactor at constant dilution rate (0.05 h-1) and total gas flow rate (240 ml/min of CO2 and 10 ml/min of air), with high-gravity all-malt wort (15Plato). The results revealed that as the fermentation temperature was increased from 7 to 15 C, the apparent and real degrees of fermentation, rate of extract consumption, ethanol volumetric productivity and con-sumption of free amino nitrogen (FAN) increased. In addition, beer produced at 15 C presented a higher alco-hols to esters ratio (2.2–2.4:1) similar to the optimum values described in the literature. It was thus concluded that primary high-gravity (15Plato) all-malt wort fer-mentation by continuous process with yeasts immobilized on spent grains, can be carried out with a good perfor-mance at 15 C