# Brewing with 10% and 20% Malted Lentils--Trials on Laboratory and Pilot Scales
## Results and Discussion
### Pilot-Scale Brewing Trial
#### 3.2.14 Sensory Analyses  
The descriptive analysis targeted a series of possible sensory attributes. This evaluation focused entirely on the aroma, and the results are visualized in a radar chart (Figure 2). Similar results were obtained for the beers, with the main difference being a fruitier aroma in the reference. Additionally, a peaish aroma was detected for the beers made with lentil malt.  
Overall, the results of the radar chart show only minor differences in the various sensorial attributes. The basic tastes--sweet, sour, bitter and acidic--were similar for all beers. A slight sweetness was noted for all beers, which could have been interpreted from  
Figure 1: Gluten concentration of the pilot-scale beers (mg/L). Mean values labelled with the same letter are not significantly different (\(p\) < 0.05). Error bars represent standard deviation of mean (n = 6).  
Figure 2: Radar chart of chosen quality attributes organoleptically assessed by a trained panel of eight evaluators. Each beer was assessed separately, and the final marks were calculated as an average value (n = 8).  
fruity and malty aromas detected by retro-nasal olfaction. Typical malt aromas, such as cereal and malty, where expected, but caramel, coffee, toffee and roasted aromas were also introduced by the dark malts used. The mentioned coffee, chocolate and roasted aromas were more noticeable in beer with 10% lentil malt. A possible explanation is that the intensity of the 10% lentil malt is less than that of the 20% adjunct but greater than that of the barley malt. As shown in the radar chart, the strongest peaish aroma was detected for beer with 20% LM adjunct, followed by 10% LM adjunct. No such aroma was detected in all-barley malt beer. A peaish aroma is common in legumes and can be regarded as an off-flavor, alongside beauty, green and hay-like aromas in legumes [75]. Alcohols, aldehydes and ketones have been reported as volatile compounds in lentils, but to date, there is no literature on other particular volatile compounds that can generate off-flavors in lentils [76]. On the one hand, lentils have lipoxygenase (LOX) activity, and therefore, off-flavors can develop from lipid oxidation, as previously reported [17]. On the other hand, most of the LOX enzymes are denatured during the kilning process [40; 64; 73; 77]. A beamy flavor was reported in lentils at the beginning of germination, which changed to a peaish off-flavor after 7 days of germination. Additionally, an unpleasant astringency, which could be connected to the glycosides present, vanished after germination [78]. Nevertheless, soaking (as in the steeping step) and heat treatment (as in kilning and subsequent wort boiling) diminish these off-flavors [75]. Therefore, the sensory panel only detected the peaish-like aroma to a minimal degree. As this aroma was not detected at all in the all-barley malt beer, the panelists were more focused on its fruity aroma, which was scored higher for this beer type. In conclusion, the use of lentil malt can definitely be detected sensorially as a peaish aroma. Possible changes in the kilning temperature of the lentils could further improve the aroma in order to produce a more acceptable beer.