Beer can be defined as a product of cereal fermentation process, and it consists of more than 90% water in addition to carbohydrates, minerals, and alcohol (on average 3.5–10%) [1
]. Last year, Brazil produced 13.9 billion liters and consumed 1.25 billion liters of beer, representing 7.0% and 6.6% of the global beer market, respectively [2
]. Beers are primarily classified according to the fermentation process [3
]. Lagers, the most consumed type of beer, are produced by low fermentation, which is usually carried out between 6 and 15 °C [2
]. In contrast, ale type beers are produced by high fermentation, occurring between 16 and 24 °C after which yeast cells rise to the surface of the fermentation media, forming a thick film that is not generally removed completely [2
]. Indeed, the transformation of wort into beer essentially represents the yeast-driven conversion of sugars into ethanol, CO2
, and many other secondary products that provide specific aromas and flavors [4
Craft beer can be defined as a distinctively flavored and brewed variety that is distributed regionally. Their popularity has benefited from innovation, creativity, typicality, and authenticity, which typifies craft beer as an experience that offers pleasure, enjoyment, sense of identity and belonging, self-fulfillment, social recognition, and sustainability [5
]. In recent years, there has been a big increase in the Brazilian market for craft beer consumption and production. In addition, craft beer is generally unfiltered, unpasteurized, and without additional nitrogen or carbon dioxide pressure [3
]. Unlike commercial beers, craft beers are mainly produced in microbreweries following the basic brewing principles and using specific recipes according to the preference of consumers. At the same time, like commercial beers, they can be brewed using different adjuncts and yeast types [6
It is well known that many compounds affect the sensory properties of craft beers, such as sugars, organic acids, hop bitter acids, polyphenols, and carbonyl compounds [6
]. The fermentation processes through the inoculated yeast (i.e., first fermentation and refermentation in craft beers) are fundamental to the aromatic profile of the final beer produced [4
]. Polyphenols are important compounds for beer quality as they can contribute to bitterness, color, body, and astringency and can therefore influence their acceptance [7
]. Almost 67 different polyphenols have been detected in beers, both from barley and hop [9
]. The most abundant phenolic acid is ferulic acid, which is found in different beer styles, especially in pilsner and weissbier [10
]. Polyphenols have a key impact on the sensory quality of beers, with a higher number of polyphenols leading to better aroma and flavor of the final product [11
Beer polyphenols come from barley malt [12
] and hop [8
], and their content depends on the type of beer and the quantity of hops added during its production. The brewing process and fermentation are also important factors as some chemical changes can occur during these processes [12
]. Three polyphenol groups—flavan-3-ol, flavonols, and phenolic acids—are found in beers and contribute to their flavor, aroma, and chemical stability [9
]. Some polyphenols act as antioxidants and prevent the oxidative degradation of beers. In addition, they provide potential benefits for human health as they inhibit mutagenic and carcinogenic agents [8
Consumers choose craft beers because they have a variety of flavors, such as malted barley, chestnut, and honey, which increases the probability of perceiving craft beers to be of a higher quality [13
]. Moreover, their consumption has become, in a qualitative approach, experienced-based and emerging from a desire for identity and distinction. The goal toward consumption is not functional but rather symbolic. [5
]. Moreover, Brazilian consumers choose craft beers because they have an individual quality value and distinct sensory attributes [14
]. Indeed, there has been a worldwide increase in the popularity of craft beers in recent times, particularly traditional ales, lagers, and even styles that do not fit in any of the two main types [3
In the present study, the relationship between polyphenols and bitterness of the main styles of craft beers brewed in Southern Brazil was analyzed, along with the preference of consumers. In addition, each style of craft beer was characterized according to its chemical composition, polyphenol content, and sensory attributes. As far as we know, few researches have been conducted with the sensorial description and composition of Brazilian artisanal beer styles, evidencing the importance of this work.
3.1. Craft Beer Composition and Color
All the craft beers tested showed best quality condition parameters according to international quality guidance [15
]. Table 2
shows the composition of craft beers. In general, the craft beers had a similar composition in sugars, density, acidity, and pH; more differences were observed in turbidity, total solids, and dry extract.
The porter style (RPO) showed a higher turbidity (230 NTU) than the other tested samples. This beer had a high pH value (4.40), more solids (10% m/v), dry extract (7.47 g/L), acidity (2.19 g acetic acid/L), sugars (2.08% w/v), and ethanol (7.0% w/w). In addition, this characteristic was detected and pointed out by the hedonic panel, which described the beer as turbid and with a dark and intense color, as expected by the analysis of parameters. The SAL exhibited minor turbidity (1.44 NTU), dry extract (3.84 g/L), solids (5.75 °Brix), and acidity (1.49 g acetic acid/L).
Regarding the color of beers, differences in L*, a*, and b* parameters were found. All samples showed high luminosity, but SAL had higher luminosity than other craft beers analyzed (Table 3
). Minor L* value was detected with porter (RPO) style, a very turbid beer (Table 2
). The L* value ranged from 14.02 (RPO beer) to 91.65 (SAL beer). The a* value, which represents the color axis green to red, ranged from −0.49 (SAL) to 33.43 (RPO). The positive values indicated a perception of red color due to the toasted barley use in craft beer production. For parameter b*, a tendency of yellow color was noticed and ranged from 24.03 (RPO) to 89.6 (IRA). The decrease in b* value of some samples of craft beers led to a reddish color and with a brown trace, as a function of a* value of color. Chroma value was positive for all craft beer samples and ranged from 32.74 (SAL beer) to 94.19 (IRA). The beer IRA showed a higher chroma when compared to other samples, representing a beer color with more quality, purity, and intensity. The h
angle oscillated from −1.556 (SAL) to 1.532 (CAP), indicating a more yellow color of beer samples. The h
is correlated to a* and b* value, and it is important to differentiate the color hue from different beer samples. The CAP beer had a more intense and yellow hue compared to the other samples (Table 3
The color expressed in EBC units varied from 7.50 (SAL) to 157 (RPO). The beer with higher EBC index (RPO: 157) showed lower luminosity (14.02), and the least intense EBC color had more luminosity (91.65).
3.2. Bitterness, Antioxidant Activity, and Polyphenols
The polyphenol content in beer is an important factor to analyze as it can improve the quality and acceptance of craft beers. Table 4
shows the content of polyphenols, antioxidant activity, and bitterness of each craft beer sample. The beers with higher level of polyphenols were RPO (1.62 mg EAG/mL), IRA (0.95 mg EAG/mL), and WSB (1.68 mg/EAL/mL). The SAL craft beer showed lower polyphenols content (0.35 mg EAG/L) compared with other samples. In Table 4
, it can be seen that the beers that presented higher content of total polyphenols were also the ones with greater antioxidant activity.
The antioxidant activity was maximal (5.58 μmol Trolox/mL) with the weissbier beer (WSB) using the DPPH method. In general, the antioxidant activity of the tested beers varied from 1.74 μmol Trolox/mL (SAL) to 5.58 μmol Trolox/mL (WSB). The beer bitterness was maximal in IPA beer (46.15 EBU), and the lowest value of bitterness was 9.52 EBU (CAP) (Table 4
). The bitterness EBC value varied depending on the content of bitter compounds and polyphenols in the beers. In this case, the craft beer with higher content of total polyphenols did not show a higher bitterness value.
3.3. Sensory Analysis of Beers
For the hedonic test of beers, 62 panelists were recruited to evaluate six different styles. This panel was composed of 57.4% females and 42.6% males. The average consumer age was 32.09 ± 10.6 years old and ranged from 20 to 56 years old. Regarding the frequency of beer consumption, 81.5% of panel reported frequently drinking beer every day and only occasionally consuming it on a weekly basis. They also consumed both commercial and craft beer brands; the most consumed craft beers were local beers, followed by the international brands of craft beers available.
Concerning the factors that influence beer consumption, most assessors chose the beer differential and typical sensory characteristics, the type of serving, the beer label design, and the beer style. The second most important factor was the place of consumption. The least important factor was the type of packaging. The most important sensory characteristics appreciated by the survey participants were the flavor and then the beer fragrance notes. Regarding the preference for styles of beer, the most cited were pilsner, weissbier, and India pale ale.
The calories contained in beer had relevance for only eight participants (12.9%) in the survey, and the clear majority of participants said they usually drink with their friends. When talking about the consumption of beer combined with some type of gastronomic preparation, 24 people (38.7%) reported that they do not care about it, 14 (22.6%) said they do not usually drink with food, and 24 assessors (38.7%) said they try to harmonize the drink with food. Regarding the factors influencing beer consumption, a majority chose the beverage differential, such as how it is served, the label, and the style. The second most important factor was the place where they drink the beer. The least important factor was the packaging. According to sensory characteristics of craft beers, the most prominent was the taste, followed by aroma. For only eight participants (12.9%) in the survey, the calories contained in beer had relevance. On the other hand, the clear majority of participants usually drink with their friends. When talking about the consumption of beer harmonized with some type of gastronomic preparation, 20 people (31.25%) reported that they do not care about it and 14 (22.6%) do not usually drink with the food and only 20 people (31.25%) try to harmonize the drink with the food. Concerning the brewing schools (English, Belgian, German, and American), 63% did not know any of them. Regarding the preference for a particular style of beer, the most cited were pilsner, weissbier, and India pale ale.
Regarding the useful ranking preference test, the least preferred beer was IPA, and the most preferred style was pilsner (CAP). The ranking preference test was considered significant (95% significance) using the Friedman test, and there was a significant difference in the preference when comparing the scores between them. Pilsner craft beer (CAP) was more preferred when compared to lager beer (SAL) and other craft beers. In fact, none of the participants chose CAP beer as the least preferred of all beer samples. Pilsner (CAP), one of the beers with the lowest number of polyphenols (0.61 mg EAG/mL) and bitterness (9.52 IBU), had a higher preference compared to the others. Thus, an increase in polyphenol level and beer bitterness led to a decrease in preference by the panel test. The IPA beer also showed a more intense bitterness (46.15 IBU), which was a factor that contributed to its low preference among beer consumers.
shows the sensory profile of different craft beer styles by QDA. This data indicates the differences in the craft beer styles according to the abovementioned sensory attributes. Aroma attributes, carbonation, hoppy, and foam were some important characteristics evaluated by beer consumers.
The CAP beer showed a high sweet flavor score (3.64) but did not show high scores for other descriptors (Figure 1
). The RPO beer exhibited good color (6.23), overall intensity (5.23), foam (5.34), malty (5.08), and smoked (3.48). The hoppiest (4.59) and fruitiest (5.24) craft beer was IPA. This craft beer had around 2.5-fold more hoppy flavor than CAP beer (1.8), which was the most preferred beer. The bitterest craft beer was IPA (7.40) and IRA (7.25). Consumers preferred beers without high polyphenols content, less bitterness (EBU units), and lower bitter and hoppy character.
Differences in the sensory profiles of craft beers were investigated by PCA, and the results are shown in Figure 2
. This analysis matrix included all sensory attributes evaluated (Figure 1
). Two principal components (PCs) were extracted, and one group of samples was discernible after analysis of PC1 versus PC2 in a biplot of samples and selected variables. In this PCA plot, PC1 explained 37.94% of total variance and PC2 explained another 29.7%. Based on the results of PCA and considering the studied beer samples, CAP, IRA, and WSB were grouped (Figure 2
). The beers IPA, RPO, and SAL did not cluster together and remained separated in the plots. The group of beers showed yeast/fermentation and sweet flavor and had a high perception of carbonation. In the upper left quadrant, the beer IPA was mainly related to the presence of floral flavor. The IPA style showed a more intense perception of floral flavor and hoppy character. The RPO positioned in the upper right quadrant was more related to the presence of more intense color besides alcoholic, malty, fruity, and overall intensity attributes (Figure 2
Beer is a very complex mixture, and its chemical composition varies considerably [24
], as shown in Table 2
. To bring more light into the differences found in craft beer consumption, the objective of this work was to explore the impact of polyphenol content and bitterness of Southern Brazilian craft beers on consumer preference. As craft beers have different flavors, aromas, etc. than the usual well-known commercial brands, their preference is increasing among consumers [13
These differences in craft beer flavors come from the ingredients used as well as the brewing process [16
]. The yeast strains used have a key impact on the final craft beer quality, either in the aroma compound production or in the interaction of some beer components, such as polyphenols [4
]. While several yeast strains are commercially accessible, the availability of new starter strains could be an important differentiating factor among craft beers produced in different microbreweries [25
]. The main ingredients used in beer production are barley, hops, water, and yeast [26
], with each ingredient playing a crucial role in the quality and composition of beers. The porter style beer, for example, is characterized as a substantial, malty dark beer with a complex and flavorful dark malt character [15
]. This beer showed high scores in composition parameters compared to other beers tested in this study. Nevertheless, in general, the tested craft beers were similar in analytical factors to the styles described in the BJCP guide [15
In addition, craft beers have distinctive and pleasant flavor characteristics, and these attributes are easily perceived by consumers [27
]. Today, consumer preferences appear to be connected to the discovery of new beer flavors [13
], which can increase the consumption of craft beers. Brazilian consumers have followed the same trend as they search for beers with high sensorial quality and differentiated and characteristic flavor and aroma, as verified in this study. The main factor that affects Brazilian beer consumers is the sensory attributes, as pointed out by other studies [13
]. The most preferred craft beer in our study was the CAP style, which mainly shows a fruity and sweet note. Additionally, consumers have a predilection to drink with friends and consider the flavor and fragrances of beer.
It must be noted, however, that this study had some limitations, in particular the few number of craft beer samples that were evaluated for each style of beer. Even so, the sensory attributes and craft beer styles selected in this study for their consumer relevance spanned a wide range of beer characteristics.
Moreover, studying consumer behavior can have great value for the beer industry as it can show how consumers represent the beer category, the associations linked to them, and the proximity across different types of beer [27
]. In addition, studies about consumer preferences can assist brewers to understand consumer attitude and translate consumer needs, wants, and expectations into manufacturing design to produce the best, most cost-competitive, and widely accepted product possible in a relatively short period [29
Beers are rich in polyphenols, which are mostly acquired from barley and hop [8
], and they were found in the six styles of beers evaluated in this study. For example, xanthohumol is the most common phenol in hop [30
]. Investigating the Brazilian beers, we found that the contents of phenolic compounds, as well as the antioxidant capacity, were like those of beers produced elsewhere in the world [2
]. Polyphenols are already extracted in the initial phase of the fermentation process, i.e., during the wort production [9
]. This study showed that polyphenols, especially the bitterness associated with it, have an important relationship with the preference of different beers among Brazilian consumers. The most preferred beer showed the lowest bitterness (Table 4
, Figure 1
) of all styles tested and the second lowest level of polyphenols (0.61 mg EAG/mL). This same relationship with bitterness was verified when analyzing consumer acceptance of craft beers and commercial brands in the Brazilian market [31
]. Understanding the sensory characteristic of bitterness in beers and how that relates to their content of polyphenols has a significant value for understanding consumer response as well as optimizing production processes [8
The malt kilning process determines the color parameter, and it is quite an important process as it can improve the acceptance of beers [26
]. The luminosity (L* value) also has a great importance because beers with higher L* value (high luminosity) show a more vivid and intense color [19
]. The lager beers show high L* values [19
].The darker and more turbid beers show big scores in fruity, floral, and malty flavors, but they still have a low preference among consumers. Beer appearance provides substantial opportunities for product differentiation, and even beers of the same type have the potential to deliver on rather different usage contexts [32
The most popular beer style in Brazil is the Germany-style pilsner, which is very light and clear [31
]. This beer style is very common in the Brazilian market and has a great familiarity to consumers. Familiar beers would be more often cited as appropriate in most of usage contexts, and that familiar and novel products would be associated with different usage contexts [32
]. Consumers perceive familiar beers to be more interesting and tasty [32
], which can increase their preference, as verified in this study. The preference order obtained from this study came from the sensory proprieties perceived by non-trained assessors because the beer samples were analyzed at the same time and were not assigned different styles.
From the sensory characterization of Brazilian beer styles, it is possible to attest that the evaluated consumers could differentiate and prefer the most aromatic and fruity beers. In addition, this distinct character is a motivation to choose and buy craft beers instead of other beer brands [29
]. In this context, the use of S. cerevisiae
strains isolated from food matrices can represent a valid approach for the selection of starters for brewing to obtain craft beers with more complex flavors [25
]. A study with Italian consumers found similar preference to beers brewed from moderately kilned/roasted malts with a milder flavor and less intense mouthfeel perceptions [28
]. More complex craft beers with remarkably increased flavors would lead to an improvement of consumer preference [29
The IPA was the lowest preferred beer and showed a higher level of bitterness attribute perception by the panel test. According to international definitions, the IPA style is a hop-forward, bitter, dryish beer with good drinkability. However, the excessive harshness and heaviness of IPA are typical faults that result from the strong flavor clashes between the hops and other specialty ingredients [15
]. Furthermore, IPA beer was differentiated by PCA (Figure 2
) from other styles because of its characteristic floral note.
Bitterness is a very important quality parameter in beer production [16
]. Nearly four out of ten consumers report that they highly appreciate sweet and fruity samples but dislike primarily bitter, burnt, and roasted notes and hoppy resinousness of beer [28
]. The bitter foods are generally disliked due to the instinctive rejection of the bitter taste [33
]. Variations in liking and the willingness to consume bitter foods can be triggered by motivational states in humans [33
]. In this study, the beer with the lowest bitterness had a higher preference among consumers. This shows bitterness is a key factor that influences beer preference and leads to a decline in consumer preference.