# Brewing with Unmulated Cereal Adjuncts: Sensory and Analytical Impacts on Beer Quality
## 3 Results and Discussion
### Sensory Evaluation of Adjunct and Control Beers
#### 3.1.3 Descriptive Analysis of Adjunct Beers
In contrast, the use of 60% barley (B) significantly decreased the lingering bitterness mean score (relative to that for barley A) and reduced the bitterness and astringency scores to lower than those for the 100% malt control. The sensory profiles of 60% barley (A), 60% barley (B) and the 100% malt control are visualised as radar plots in Figure 1. Use of 60% unmalted barley (B) gave a closer match to the profile of the all malt control beer, although it was on average rated a little more sour, but less malty, smoky and plum-fruit flavoured. Whereas, in comparison use of 60% unmalted barley (A) led to a beer which was rated on average as more sour, bitter and astringent, which had a more lingering bitterness. This demonstrates that processing applied to the barley grain can diminish unfavourable sensory attributes that are associated with high inclusions of unmalted barley. Use of 60% unmalted wheat adjunct led to beers that were characterised by the highest perception of banana aroma and flavour and the highest perception of smoky aroma. Strong phenolic and some smoke character are characteristic of Belgian white beers (Witbier) made with unmalted wheat; however, this is a result of the phenolic off-flavour positive (POF+) yeast strains used when brewing Belgian beers. The use of unmalted wheat in lager has been described as creating a 'neutral type of beer' with a specific, refreshing taste [15]. However, this is the first study that has identified specific flavour characteristics relating to the use of high inclusions of unmalted wheat in lager. The inclusion of 60% torrefied rice was characterised by significantly higher attribute scores for green apple flavour, and the highest rating score for the green apple aroma attribute, although this attribute was not statistically significant. The inclusion of 30% rice caused a significant increase in the sweetcorn/cooked vegetable aroma detected. The change in perception of these attributes did not linearly increase with the proportion of rice in the grist, highlighting that these flavour differences are not a direct flavour imparted by the rice, rather they are most likely associated with changes in fermentation vigour as a result of adjunct-linked reductions in soluble nitrogen. In the brewing literature, beers produced with all rice have been described as having low concentrations of flavour attributes and relatively flat or neutral character compared to an all malt beer [16; 17]. Use of 60% torrefied maize resulted in beer with the highest mean score for sourness which was significantly more sour than the all malt control and the wheat adjunct beers. A moderate sour taste is necessary to balance the flavour of beer. Nevertheless, too strong a sour taste will destroy the harmony of the beer flavour [18]. A prominent sour taste can be perceived with adjunct beers in which words have weak buffering capacity and a resultant change in pH of the beer [18]. [PERSON]'s post-hoc analysis was also performed on attribute scores for all eighteen attributes creating a comparison of each sample with the 100% malt sample as a control. Two samples had significantly different sensory attribute scores compared to the control (\(p<0.05\)). 60% maize was significantly more sour and 60% rice had significantly more green apple flavour compared to the 100% malt beer. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Modality**} & \multirow{2}{*}{**Attribute**} & **100\%** & **Malt** & **Barley (A)** & **Barley (B)** & **Wheat** & **Rice** & **M Maize** \\  & & **Control** & 30\%** & 60\% & 30\% & 60\% & 30\% & 60\% & 30\% & 60\% & 30\% & 60\% \\ \hline \multirow{6}{*}{Aroma} & Green Apple/Emulsion Paint & 2.22\({}^{\circ}\) & 2.23\({}^{\circ}\) & 2.86\({}^{\circ}\) & 2.24\({}^{\circ}\) & 1.95\({}^{\circ}\) & 2.67\({}^{\circ}\) & 2.78\({}^{\circ}\) & 2.61\({}^{\circ}\) & 3.86\({}^{\circ}\) & 2.87\({}^{\circ}\) & 2.36\({}^{\circ}\) \\  & Sweetcom/Cooked Veg.