**5. Craft and special beers: classification**

A single beer style, lager beer, has long been the main dominant beer in the world market. However, a worldwide change in trend for the last decade has been registered due to the growing interest in craft and specialized beer [34]. A significant growth in the number of breweries, the variety of styles and the total volume of production had been observed in previous years [35].

But the reasons for the growth are multiple: first, increase in the demand for high more flavorful and stronger beers [34, 36]. This is particularly important in the case of American consumers, often not satisfied with the dominant in the market American pale lagers. An increase in flavors (malted barley, chestnut, honey flavored) and a more readily quality perceived are the main factors to choose craft beer

**87**

**Figure 2.**

*Main criteria to classify craft and special beers.*

*Craft Beers: Current Situation and Future Trends DOI: http://dx.doi.org/10.5772/intechopen.90006*

use of emerging technologies in brewing (**criterion 5**).

community [36].

beers (**Figure 2**).

special and craft beers.

instead of commercial beer between habitual beer drinkers [37]. Second, exclusivity and "unique drinking experiences" are also highly rated by craft beer consumers [34, 38]. Finally, even though traditional brands of beer are closely linked to very specific places [39], craft beer is part of a broader neolocalism movement in which people are demanding goods and services that have a connection with the local

Taking into account that all beer types evolve from the combination and relationships among ingredients, processing, packaging, marketing and culture, it is therefore necessary to establish some criteria to establish differences between

This section analyzes the main criteria for classifying beers as special or craft

The first element taken into account is the production output of beer per year (**criterion 1**). Craft beer are characterized by small production output and their "small," "independent," and "traditional" character. These characteristics are compatible with others which have been traditionally used to classify beer styles and now they are assuming new importance and making possible to enrich traditional beer brewing: we refer to type of fermentation and yeast strain selection (**criterion 2**). Here, we will look at non-*Saccharomyces* brewing yeasts which require special attention [40, 41]. While malted barley remains the main source of sugars for fermentation in the production of beer, the ingredients can be changed based on the region and preference of the consumer. Innovative ingredients in wort production can be used as a valuable source of variation in craft beer production (**criterion 3**) The two last criteria are relatively recent and novel and are related with the development of special beers in the perspective on health and nutrition (**criterion 4**) and with the

#### *Craft Beers: Current Situation and Future Trends DOI: http://dx.doi.org/10.5772/intechopen.90006*

*New Advances on Fermentation Processes*

*Percentage of craft beer producers (2013–2017).*

increased globally. In fact it passed from 671 to 2378 in the UK (traditionally beer-producing and beer-drinking country), and from 1321 to 6266 in the USA, an increase of 354 and 474% respectively, within the same period (not traditional beer producer country). This increase in number of craft breweries and production volume run up to an increase in compound annual growth rate (CAGR) within the sector. Craft brewing continues to take market share away from the largest brewing companies. According to Brewers Association report (the U.S. beer sales volume growth 2017, National beer sales and production statistical data), the overall U.S. beer volume sales were down 1% in 2017, whereas craft brewer sales continued to grow at a rate of 5% by volume, reaching 12.7% of the U.S. beer market by volume. Craft production grew the most for microbreweries. Retail dollar sales of craft increased 8%, up to \$26.0 billion, and now account for more than 23% of the \$111.4 billion U.S. beer market [27]. Percentage of craft beer producers (2013–2017)

There are various factors, which favored this increase in overall craft beer consumption. These factors include per capita income growth, the availability of alternatives toward the production of successful and high levels of quality beers, increased health concerns, and the emergence of new government regulations that affects directly the sustainability issue and consistency and innovation among many

A single beer style, lager beer, has long been the main dominant beer in the world market. However, a worldwide change in trend for the last decade has been registered due to the growing interest in craft and specialized beer [34]. A significant growth in the number of breweries, the variety of styles and the total volume

But the reasons for the growth are multiple: first, increase in the demand for high more flavorful and stronger beers [34, 36]. This is particularly important in the case of American consumers, often not satisfied with the dominant in the market American pale lagers. An increase in flavors (malted barley, chestnut, honey flavored) and a more readily quality perceived are the main factors to choose craft beer

**86**

can be seen in **Figure 1**.

**5. Craft and special beers: classification**

of production had been observed in previous years [35].

others.

**Figure 1.**

instead of commercial beer between habitual beer drinkers [37]. Second, exclusivity and "unique drinking experiences" are also highly rated by craft beer consumers [34, 38]. Finally, even though traditional brands of beer are closely linked to very specific places [39], craft beer is part of a broader neolocalism movement in which people are demanding goods and services that have a connection with the local community [36].

Taking into account that all beer types evolve from the combination and relationships among ingredients, processing, packaging, marketing and culture, it is therefore necessary to establish some criteria to establish differences between special and craft beers.

This section analyzes the main criteria for classifying beers as special or craft beers (**Figure 2**).

The first element taken into account is the production output of beer per year (**criterion 1**). Craft beer are characterized by small production output and their "small," "independent," and "traditional" character. These characteristics are compatible with others which have been traditionally used to classify beer styles and now they are assuming new importance and making possible to enrich traditional beer brewing: we refer to type of fermentation and yeast strain selection (**criterion 2**). Here, we will look at non-*Saccharomyces* brewing yeasts which require special attention [40, 41]. While malted barley remains the main source of sugars for fermentation in the production of beer, the ingredients can be changed based on the region and preference of the consumer. Innovative ingredients in wort production can be used as a valuable source of variation in craft beer production (**criterion 3**) The two last criteria are relatively recent and novel and are related with the development of special beers in the perspective on health and nutrition (**criterion 4**) and with the use of emerging technologies in brewing (**criterion 5**).

**Figure 2.** *Main criteria to classify craft and special beers.*

## **5.1 Production output of beer per year (scope of craft beer)**

The annual beer production allows distinguishing between *larger breweries massproducing beer* (annual production capacity of up to 6 million barrels) and *craft beers* or "small" scale breweries (less than 6 million barrels; where 1 BBL = 339 12 oz bottles of beer or 235 half-liter bottles of beer) [26, 42].

According to Kleban and Nickerson [42], small scale beers have different considerations:


The American craft brewing industry assumes that in addition to low volume production, further requirements are expected by the craft beers [36]. They are *independent* in that and not more than 25% of the business is owned by another member of the alcohol industry who is not a craft brewer. *Traditional ingredients* (water, malt, hops, yeast) must also be used in the brewing process although *innovation* in terms of reinterpreting historic beer styles or developing new styles is a hallmark of the industry.

#### **5.2 Selection of the yeast strain and type of fermentation**

The main brewing classification criterion particularly relies on the selection of the yeast strain and type of fermentation [35, 41]. Two types of brewing yeast were originally classified based on their flocculation behavior during fermentation.

Beers are classified into two large groups according to the yeast strain and type of fermentation: Ale beers and Lager beers. **Ale yeasts or top-fermenting yeasts**, which are *Saccharomyces cerevisiae* strains, rise up to the surface of the vessel with the escaping carbon dioxide gas bubbles and become entangled in the fermentation head, facilitating their collection by skimming.

Ale yeast fermentation temperature ranges between 15 and 20°C. **Lager yeast or bottom-fermenting yeast** does not rise and becomes entrapped in the foam but settles out at the end of the fermentation. Lager worts often ferment at lower temperatures (8–14°C) than ale yeasts and are therefore much slower.

Ale beers represent only a small percentage of the total beer consumption. They are very common in Britain, Germany, Canada's eastern provinces, the United States and, last but not least, Belgium. Until the sixteenth century, ale was the main type of beer in Europe [43]**.**

Standard/ordinary bitter (Britain), English pale ale (Britain), Mild (Britain), Brown Porter (Britain), Robust Porter (Britain), Dry stout (Ireland), Sweet stout (Britain), Kölsch (Germany, Cologne), Lambic (Belgium), Rauchbier (Germany) and Weizen/Weissbier (Germany) are some examples of ale beer types.

Lager beer is the dominant style in almost all countries and represents more than 90% of the beer produced worldwide [43]**.**

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*Craft Beers: Current Situation and Future Trends DOI: http://dx.doi.org/10.5772/intechopen.90006*

(Germany), Eisbock (Germany).

important and significant.

*5.2.1 Use of non-Saccharomyces*

Some principal Lager beer types are: German Pilsner (Pils) (Germany), Bohemian Pilsener (Czech Republic), Classic American Pilsner (United States), Vienna Lager (Austria), Oktoberfest/Märzen (Germany), Dark American Lager (United States), Munich Dunkel (Germany), Schwarzbier (Black Beer) (Germany), Maibock/Helles Bock (Germany), Traditional Bock (Germany), Doppelbock

ketones and esters are produced by yeast during fermentation. Although there are many strains of brewing yeast (*Saccharomyces cerevisiae*) for beer production, the choice of suitable yeasts to produce desirable tastes and flavors in beer is very

Several non-*Saccharomyces* yeasts can be used successfully in the making of craft beers with interesting possibilities. Yeasts such as *Lachancea thermotolerans*, *Torulaspora delbrueckii*, *Hanseniaspora vineae* and *Schizosaccharomyces pombe* can help to modulate acidity, aroma, mouthfeel or even color [41, 44]. As the final alcoholic degree in beers is lower than in wines, and normally ranging between 4 and 8% vol, the use of medium fermentative power non-*Saccharomyces* species is possible because most of these yeasts are able to ferment reaching this ethanol level. *Lachancea thermotolerans* is trending yeast in fermented beverages because of its ability to ferment until 4–9% vol producing high amounts of lactic acid from sugars. Therefore, it can be used to decrease pH of beverages [45–47]. Moreover, interesting effects in beer aroma can be reached by the production of fruity esters [48]. The use of *L. thermotolerans* has been also described in beer technology [49, 50]. In the brewing of craft beers, *L. thermotolerans* can be used not only in the primary fermentation of the wort but also during the second fermentation in bottle to produce the suitable foam and CO2 pressure. However, the most interesting application is in the production of sour beers because of the natural biological acidification during wort fermentation [46]. Moreover, even when the early use of *L. thermotolerans* has been proposed in winemaking in which the use of suitable species of these yeasts can produce pH reductions of 0.5 pH units [47] and the use in beer technology is even more effective due to the lower buffer effect in beer compared with wine. In our lab, we reached pH reductions of 1 pH unit [51]. The sensory effect of this acidity is described as a citric acidity without dairy hints because of the low production of acetoin and diacetyl [47]; moreover, the volatile acidity produced by *L. thermotolerans* is very low compared to volatile acidity produced by selected *S. cerevisiae*. *Torulaspora delbrueckii* is another versatile yeast suitable for beer production. It has a medium fermentative power and improves the formation of fruity esters in addition to a low production of volatile acidity. These characteristics make it a good yeast for the initial fermentation of the must and the subsequent in bottle [50]. Also it is possible the use of this yeast sequentially or in mixed cultures with *S. cerevisiae* [52] or *S. pombe* [53]. It has been described as yeast able to decrease volatile acidity during fermentation. The ability to ferment sugars easily reaching 7–9% vol makes it interesting also for secondary bottle fermentation [52]. The production of 2-phenylethyl acetate, a floral ester with positive floral aroma, is increased during fermentation with *T. delbrueckii*; moreover, high amounts of 3-ethoxy propanol are formed by this species [52]. The release of polysaccharides is also improved by the

fermentation with *T. delbrueckii* affecting mouthfeel and structure [54].

*Hanseniaspora vineae* is an apiculate yeast able to produce fresh and complex fermentation, increasing fruity aroma and producing full bodied structure [55]. It is possible

In all beers cited, the flavor-active compounds such as acids, alcohols, aldehydes,

#### *Craft Beers: Current Situation and Future Trends DOI: http://dx.doi.org/10.5772/intechopen.90006*

*New Advances on Fermentation Processes*

considerations:

a hallmark of the industry.

of beer in Europe [43]**.**

**5.1 Production output of beer per year (scope of craft beer)**

bottles of beer or 235 half-liter bottles of beer) [26, 42].

• Minimum production quantity: **Nanobreweries**.

same floor of production (**Brewpub**).

breweries (**Contract Brewing Company**).

their malt flagship (**Regional Craft Brewery**).

**5.2 Selection of the yeast strain and type of fermentation**

head, facilitating their collection by skimming.

90% of the beer produced worldwide [43]**.**

The annual beer production allows distinguishing between *larger breweries mass-*

• The place of sale of beer: production is sold outside (Microbreweries) or on the

• Brewing companies that outsource their production to other already established

• Over 50% or more of their volume production focuses on all-malt beers and/or

The American craft brewing industry assumes that in addition to low volume production, further requirements are expected by the craft beers [36]. They are *independent* in that and not more than 25% of the business is owned by another member of the alcohol industry who is not a craft brewer. *Traditional ingredients* (water, malt, hops, yeast) must also be used in the brewing process although *innovation* in terms of reinterpreting historic beer styles or developing new styles is

The main brewing classification criterion particularly relies on the selection of the yeast strain and type of fermentation [35, 41]. Two types of brewing yeast were originally classified based on their flocculation behavior during fermentation.

Beers are classified into two large groups according to the yeast strain and type of fermentation: Ale beers and Lager beers. **Ale yeasts or top-fermenting yeasts**, which are *Saccharomyces cerevisiae* strains, rise up to the surface of the vessel with the escaping carbon dioxide gas bubbles and become entangled in the fermentation

Ale yeast fermentation temperature ranges between 15 and 20°C. **Lager yeast or bottom-fermenting yeast** does not rise and becomes entrapped in the foam but settles out at the end of the fermentation. Lager worts often ferment at lower

Ale beers represent only a small percentage of the total beer consumption. They are very common in Britain, Germany, Canada's eastern provinces, the United States and, last but not least, Belgium. Until the sixteenth century, ale was the main type

Standard/ordinary bitter (Britain), English pale ale (Britain), Mild (Britain), Brown Porter (Britain), Robust Porter (Britain), Dry stout (Ireland), Sweet stout (Britain), Kölsch (Germany, Cologne), Lambic (Belgium), Rauchbier (Germany)

Lager beer is the dominant style in almost all countries and represents more than

temperatures (8–14°C) than ale yeasts and are therefore much slower.

and Weizen/Weissbier (Germany) are some examples of ale beer types.

*producing beer* (annual production capacity of up to 6 million barrels) and *craft beers* or "small" scale breweries (less than 6 million barrels; where 1 BBL = 339 12 oz

According to Kleban and Nickerson [42], small scale beers have different

**88**

Some principal Lager beer types are: German Pilsner (Pils) (Germany), Bohemian Pilsener (Czech Republic), Classic American Pilsner (United States), Vienna Lager (Austria), Oktoberfest/Märzen (Germany), Dark American Lager (United States), Munich Dunkel (Germany), Schwarzbier (Black Beer) (Germany), Maibock/Helles Bock (Germany), Traditional Bock (Germany), Doppelbock (Germany), Eisbock (Germany).

In all beers cited, the flavor-active compounds such as acids, alcohols, aldehydes, ketones and esters are produced by yeast during fermentation. Although there are many strains of brewing yeast (*Saccharomyces cerevisiae*) for beer production, the choice of suitable yeasts to produce desirable tastes and flavors in beer is very important and significant.

#### *5.2.1 Use of non-Saccharomyces*

Several non-*Saccharomyces* yeasts can be used successfully in the making of craft beers with interesting possibilities. Yeasts such as *Lachancea thermotolerans*, *Torulaspora delbrueckii*, *Hanseniaspora vineae* and *Schizosaccharomyces pombe* can help to modulate acidity, aroma, mouthfeel or even color [41, 44]. As the final alcoholic degree in beers is lower than in wines, and normally ranging between 4 and 8% vol, the use of medium fermentative power non-*Saccharomyces* species is possible because most of these yeasts are able to ferment reaching this ethanol level.

*Lachancea thermotolerans* is trending yeast in fermented beverages because of its ability to ferment until 4–9% vol producing high amounts of lactic acid from sugars. Therefore, it can be used to decrease pH of beverages [45–47]. Moreover, interesting effects in beer aroma can be reached by the production of fruity esters [48]. The use of *L. thermotolerans* has been also described in beer technology [49, 50]. In the brewing of craft beers, *L. thermotolerans* can be used not only in the primary fermentation of the wort but also during the second fermentation in bottle to produce the suitable foam and CO2 pressure. However, the most interesting application is in the production of sour beers because of the natural biological acidification during wort fermentation [46]. Moreover, even when the early use of *L. thermotolerans* has been proposed in winemaking in which the use of suitable species of these yeasts can produce pH reductions of 0.5 pH units [47] and the use in beer technology is even more effective due to the lower buffer effect in beer compared with wine. In our lab, we reached pH reductions of 1 pH unit [51]. The sensory effect of this acidity is described as a citric acidity without dairy hints because of the low production of acetoin and diacetyl [47]; moreover, the volatile acidity produced by *L. thermotolerans* is very low compared to volatile acidity produced by selected *S. cerevisiae*.

*Torulaspora delbrueckii* is another versatile yeast suitable for beer production. It has a medium fermentative power and improves the formation of fruity esters in addition to a low production of volatile acidity. These characteristics make it a good yeast for the initial fermentation of the must and the subsequent in bottle [50]. Also it is possible the use of this yeast sequentially or in mixed cultures with *S. cerevisiae* [52] or *S. pombe* [53]. It has been described as yeast able to decrease volatile acidity during fermentation. The ability to ferment sugars easily reaching 7–9% vol makes it interesting also for secondary bottle fermentation [52]. The production of 2-phenylethyl acetate, a floral ester with positive floral aroma, is increased during fermentation with *T. delbrueckii*; moreover, high amounts of 3-ethoxy propanol are formed by this species [52]. The release of polysaccharides is also improved by the fermentation with *T. delbrueckii* affecting mouthfeel and structure [54].

*Hanseniaspora vineae* is an apiculate yeast able to produce fresh and complex fermentation, increasing fruity aroma and producing full bodied structure [55]. It is possible

to find strains with fermentative power close to 9% vol, which facilitate its use not only for primary fermentation but also for bottle fermentation. Moreover, it is a persistent yeast that can be found until the end of the alcoholic fermentation in wines and therefore also in beers because of the lower alcoholic degree. During the fermentation with *H. vineae*, an increase in the concentration of acetyl esters, benzenoids, and sesquiterpenes [56, 57], and a decrease in the contents of alcohols and acids occurs. Intense either β-glucosidase or β-xylosidase activities has been described in some strains of *H. vineae* increasing the levels of hotrienol and 2,6-dimethyl-3,7-octadien-2,6-diol during fermentation [58]. It is especially noticeable the production of 2-phenylethyl acetate by *H. vineae* [55], compared with other *Hanseniaspora*/*Kloeckera* species.

*Schizosaccharomyces pombe* is a fission yeast able to produce maloalcoholic fermentation, and some strains can reach 13–15% vol of ethanol during fermentation [59, 60]. The peculiar metabolism of *S. pombe* produces an intense degradation of malic acid together with a significant release of pyruvate in the fermentative media [60]. *S. pombe* is especially resistant to some common preservatives such as sulfur dioxide, actidione, benzoic acid, and dimethyl dicarbonate [59, 61]. The main drawback of this yeast is the high production of volatile acidity. Concerning its structure this species has a peculiar and dense 2-layer cell wall. The autolysis produces the release of high amount of polysaccharides during maturation improving the mouth feel of beers [62]. This property can be especially interesting to produce full-bodied and soft bottle-aged beers. Moreover, we have observed intense bottle fermentation with good foam properties. The aromatic profile in beers is fruity and fresh when this is yeast is used specially in bottle fermentation.

#### **5.3 Innovative ingredients**

Raw material in wort production and parameters in production lead to produce an unlimited number of beer types. It might be argued that *beer is a horizontally differentiated product*. [35]. In fact, beers are quite similar in most respects but small differences in their composition can greatly affect both appearance and flavor [63].

We are going to examine each one of the raw materials separately.

#### *5.3.1 Water*

Water is quantitatively the main ingredient of beers; it forms more than 90% and often even more than 94% of the final product. The chemical composition of water has a determinant effect on beer properties and contributes significantly to the final beer flavor. The balance of minerals in brewing water will affect the flavor character and flavor perception of malt, hops, and by-products of fermentation. It may also influence the performance of yeast, which in turn influences the flavor, aroma, and mouthfeel of beer.

Chemical composition of water of the localities where famous beer styles were originated are very different in approximate ionic concentrations (in ppm). The chemical composition of water of Pilzen, Munich, Dortmund or Vienna is typical between Lager examples. Burton-on-Trent, Dublin or Edinburgh are typical between ale examples**.**

#### *5.3.2 Malt*

Malted barley is the main source for fermentable sugars used by yeasts in the traditional brewing of beers [64].

Depending on the conditions (time and temperature), pale or amber-colored or even dark malts are obtained; the color being due to caramelization of sugars

**91**

**Figure 3.**

*Craft Beers: Current Situation and Future Trends DOI: http://dx.doi.org/10.5772/intechopen.90006*

on the malting process [68] and its associated cost.

trations of roasted malt addition on sensory properties of beer.

can also be changed by altering the sugar and amino acid spectra in wort.

but also with the particular character of the selected hop variety [66]**.**

ent in the wort.

*5.3.3 Adjuncts*

commonly used.

*5.3.4 Hops*

hop oil and hop polyphenols [70].

*Effect of roasted barley addition on beer sensory properties.*

and to Maillard-type reactions [65]. The variety of barely and the malting process influences the type and quality of beer [66]. **To elaborate craft beer, the right malt** is a **key factor** because craft beers include high proportion of adjuncts and enzymatic activity of malt has to ensure adequate hydrolysis of all the starch pres-

Malted barley is the main source for fermentable sugars used by yeasts in the traditional brewing, Other grains, malted or not, have been included to provide fermentable carbohydrates to the wort in addition to those from malt [63]. In former times, most cereals were used for malting, emmer, oats, spelt wheat, bread wheat were widely used and, in Estonia, rye was used up until the nineteenth century [67]. Outside Europe, millet, rice, maize and tuber plants have been, and are still,

Bogdan and Kordialik-Bogacka [64] estimate that 85–90% of beer worldwide is now produced with adjuncts. Traditionally they had been used because they lead to reduce the cost of raw materials. When adjuncts are selected as unmalted grains, they present the added advantage of improved sustainability, by reducing reliance

**Craft brewing is increasing the use of adjuncts** [68] because they lead to create a unique beer **flavor/aroma** [69]. **Figure 3** shows the influence of different concen-

Appropriately chosen adjuncts can contribute to light or dark colors, improved colloidal or foam stability and prolongation beer shelf-life [64]. The flavor profile

Hops (*Humulus lupulus* L.) are almost exclusively consumed by the brewing industry. Although hops are only a minority ingredient, they have significant impact on the sensory properties of beer [65]. It contributes not only to bitter flavor

This is mainly due to its particular chemical composition in: the hops resins, the

and to Maillard-type reactions [65]. The variety of barely and the malting process influences the type and quality of beer [66]. **To elaborate craft beer, the right malt** is a **key factor** because craft beers include high proportion of adjuncts and enzymatic activity of malt has to ensure adequate hydrolysis of all the starch present in the wort.
