Flavor compounds’ formation and fermentative parameters of continuous high gravity brewing with yeasts immobilized on spent grains were evaluated at three different 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 (15°Plato). 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 consumption of free amino nitrogen (FAN) increased. In addition, beer produced at 15 °C presented a higher alcohols 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 (15°Plato) all-malt wort fermentation by continuous process with yeasts immobilized on spent grains, can be carried out with a good performance at 15 °C.
展开▼
机译：在三种不同的温度（7、10和15°C）下评估了固定在废谷物上的酵母连续高重力酿造过程中风味化合物的形成和发酵参数。该测定法在鼓泡塔反应器中以恒定稀释率（0.05 h-1）和总气体流速（240 ml / min的CO2和10 ml / min的空气）进行，采用高重力全麦芽汁（15 °Plato）。结果表明，随着发酵温度从7°C升高到15°C，表观和真实的发酵度，提取物消耗速率，乙醇体积生产率和游离氨基氮（FAN）消耗均增加。此外，在15°C下生产的啤酒具有较高的醇与酯之比（2.2–2.4：1），与文献中所述的最佳值相似。因此得出的结论是，通过将酵母固定在废谷物上的连续过程进行的初次高重力（15°Plato）全麦芽汁发酵可以在15°C下进行，且性能良好。
展开▼
