The impact of grain composition and microstructure when mashing unmalted sorghum with high- and low-temperature enzyme systems.

There are a number of challenges associated with brewing with sorghum as compared to barley malt. These include a relatively high starch gelatinisation temperature, reduced content of diastatic enzymes, and poor wort FAN yields. In the present study, a novel low-temperature mashing system was compared to a traditional high-temperature mashing system in terms of wort quality produced from five unmalted sorghum cultivars (2 brewing and 3 non-brewing). The low-temperature worts were of comparable quality to those resulting from the more energy intensive traditional method. Furthermore, mashing of non-brewing cultivars was able to produce worts of comparable quality to brewing sorghums. Results indicated that although brewing sorghums were lower in protein, it was protein structure more than protein content that influenced brewing performance. RVA profile was the easiest way of identifying this characteristic as potentially problematic.