Characterising the sensory profiles of beers made from new hop varieties is of considerable importance for their application in brewing. New Czech bitter varieties Boomerang and Gaia were tested in three-year pilot brews (200 l) of 12% single-hopped pale lager, produced in kettle and kettle+dry-hopped variants. The hop-derived aroma and bitterness profile of the beers was evaluated using a comprehensive descriptive method. Hop-related volatiles in beer were determined by GC/MS-MS method. Both of these bitter varieties showed a pleasant bitterness profile even in dry-hopped beers. The overall impression of the beers from the varieties tested was favourable, at the level of the control beer (Saaz). The profile of hop derived volatiles and aroma in beers from Gaia and Boomerang varieties were different. The results show the potential of Boomerang for both single kettle-hopped beers and dry-hopped lagers due to its interesting aroma profile (spicy, herbal, floral). The Gaia variety can be used in a similar way, with a preference for dry hopping to give a well-balanced hop-derived aroma profile. Both varieties have shown considerable potential for the production of new beer brands, and their drought tolerance may also help their widespread cultivation.

Historic spring barley varieties can be a source of resistance to abiotic (drought) and biotic (diseases) environmental factors in breeding programs. They can be a source of the new technological characteristics of malt or sensory characteristics of beer. Beers made from Pilsner malt from two historical varieties – Chlumecky (1902) and Stupicky Starocesky (1926) and two contemporary varieties – Bojos and Sebastian (2005) were evaluated. These beers have beenflavoured with valerian, which in combination with hops has been shown to have anxiolytic and sedative effects. A comparison of elementary and sensory parameters of beers with addition of 0.5 g.L-1 and 1.5 g.L-1 of valerian to two different series of beers was carried out. The Chlumecky samples had the lowest content of alcohol by volume (6.17% and 5.12%) in both batch series of beer and the highest real extract in the first batch series (4.11%). The samples of beer from the Stupicky Starocesky variety had low real extract (3.57% and 3.60%) and high content of alcohol by volume in both batch series (6.34% and 5.96%). In terms of sensory analysis it means that beers brewed from the malt made from the older barley varieties – Chlumecky and Stupicky Starocesky with addition of 0.5 g.L-1 of valerian had the highest overall impression.

After the harvest 2023, three varieties were registered in the Slovak Republic after three years of testing: the spring barley variety LG Rhapsody, the two-row winter barley variety Claudia, and the six-row winter barley variety MH Irén. The malting quality was determined for the varieties LG Rhapsody and Claudia. LG Rhapsody gave extract in malt dry matter of 83.2%. Proteolytic modification of this variety was high (Kolbach index 52.3%). The diastatic power (343 WK), the quality of the sweet wort (apparent final attenuation 82.1%), and the cytolytic modification (friability 94% and β-glucan content 60 mg/l) were at an optimal level. In all cases, the variety gave a clear sweet wort. The winter two-row barley variety Claudia gave a sweet wort with an extract of 81.5%. Kolbach index (46.2%) and diastatic power (508 WK) were at optimal levels. The quality of the sweet wort (apparent final attenuation 80.5%) and the cytolytic modification (friability 83% and β-glucan content of the wort 169 mg/l) were at an average level.

The course of weather conditions during the growing season, but also beyond it, decides the economics of hop cultivation every year. Ongoing climate changes manifested by more frequent occurrence of compound hot and dry waves affect hop cultivation not only in the Czech Republic, but in the entire region of Central Europe. The paper evaluates the harvest results (yields, alpha acid content) of four Czech hop varieties in the period 2019–2022 with a focus on the weather diametrically opposed vintages 2021 and 2022 on a specific agricultural farm in the Žatec (Saaz) hop-growing region. While the 2021 vintage was rich in precipitation in the decisive vegetation phase, the 2022 vintage was very dry and hot. The age of the plants significantly influenced the alpha acid content of the varieties Saaz, Sládek and Premiant independently of the vintage. Young growths of the Saaz variety contained at least 60% rel. more alpha acids than older growths (more than 5 years old), while the increase in the Sládek variety was 30–40% rel. and in the Premiant variety 20–25% rel. In the case of the variety Agnus, the age of the plants did not have a demonstrable effect on the content of alpha acids. In 2021 the yields of all varieties were negatively affected by the calamitous occurrence of downy mildew. In 2022, the rainfall deficit was so large that it could not be fully compensated even by the maximum use of drip irrigation. Of the evaluated varieties, the Agnus variety coped best with the different weather conditions of the assessed vintages. This shows that the cultivation of climate resistant varieties is one of the promising but time-consuming ways to face the expected climate changes. Other options include regular renewal of hop growths, consistent regionalization, i.e. planting hop in locations that are suitable for the given variety and efficient use of irrigation systems.

Czech bitter varieties were evaluated between 2010 and 2022. Hop varieties displayed an average content of alpha acids between 10.24% w/w (Agnus) and 13.73% w/w (Gaia). Variability below 15%, proved good stability of alpha acids content in all tested bittering hops. All varieties showed a decrease in the content of alpha acids over a period of 13 years of hop cultivation. The highest content of beta acids was determined in Gaia (7.30% w/w). In contrast, the lowest content of beta acids was found in Rubín (3.73% w/w). The new bitter genotypes Uran and 5304 had an average alpha acid content of 11.56% w/w and 10.82% w/w, respectively. Uran showed an average beta acid content of 5.47% w/w and for the genotype 5304 it was 3.61% w/w. In terms of the alpha/beta acids ratio, the hop varieties can be divided into three groups. The first group included the varieties with an alpha/beta acids ratio below 2, i.e. Vital, Boomerang and Gaia. While Agnus and Uran displayed an alpha/beta ratio slightly above 2. The highest alpha/beta ratio above 3 was found in Rubín and the 5303 genotype.

Historical Czech malting barley varieties Chlumecký, Stupický staročeský, Opavský Kneifel, and Diamant were tested in pilot malting and brewing tests (50 L) of 12% pale lager and compared with five Czech barley varieties recommended for the production of the beer with the protected geographical indication ‘České pivo’. The grain yield of the historical varieties (6.00–7.83 t/ha) was lower compared to the current varieties (8.23–9.39 t/ha). The malts from the historical varieties had high nitrogen content (12.45–13.89%), and low extract (75.2–78.6%, proteolytic (Kolbach index 37.4–40.9%) and cytolytic modification (friability 46.2–57.7%) was also low. Apart from lower extract yield and lower beer filtration rate, the experimental malts from the historical varieties were well processable in the pilot brewery. The sensory quality of the beers was very good (overall impression 3.3–3.8 points), fully comparable to beers made from malts from current barley varieties (3.4–3.9 points). Cluster analysis clearly differentiated the sensory profile of beers of historical and current barley varieties. The historical malting barley varieties under study may find their use mainly in the production of regional microbreweries.

Exposure of beer to light results in the formation of undesirable flavours or complete spoilage. Photo-damaged beerhas a specific, so-called skunky or light-struck flavour (LSF). The compound responsible for LSF is 3-methylbut-2-ene-1-thiol (MBT). Riboflavin (RF) plays a key role in the formation of MBT. It absorbs light in the blue part of thespectrum and transfers excitation energy to isohumulones. This process is accompanied by the decomposition of RF,which causes a decrease in the absorbance of the sample at 450 nm. The decomposition is directly related to theformation of LSF. In this study, the decrease in absorbance associated with the defined illumination of model and realbeer directly in commercial bottles was measured. The decrease in absorbance correlated with the decrease in RFconcentration and the formation of LSF detected by the sensory panel. The Light-Struck Flavour Susceptibility Indexwas introduced as a rate of the beer susceptibility to light degradation and the formation of LSF.

Although barley malt is considered a traditional appropriate raw material for beer production, there are several reasons to introduce alternative sugar or starchy materials into brewing. Economic and market demands play a crucial role in the selection of raw materials. However, different adjuncts bring various technological challenges due to their specific physicochemical properties as well as the degree of processing when entering to the brewery. This review is focused on the current practice as well as on innovations in the use of several barley malt substitutes. The beer production from various proportions of adjuncts is presented step by step and the pros and cons associated with technological changes and equipment are discussed. The impact on sensory character is also considered. The aim of the paper is to offer theoretical background and reveal the latest possibilities for practice.

Non-microbial beer turbidity of lager beers often indicates a technological problem. Therefore, the occurrence of permanent haze in filtered and stabilized beer should not be underestimated. In this study, practical examples from industrial breweries, where several types of non-microbiological haze of colloidal were identified, are presented. These examples of haze were caused by slightly different factors, and as a result, they had a different microscopic image. It is often accompanied by mechanical impurities and sometimes by microorganisms that function as nucleation centers. Moreover, a very interesting example of almost brilliant permanent beer haze caused by the destruction of yeast cells with the following pouring intracellular contents of cells into beer is introduced. This phenomenon, which could be called “precedent”, was caused by a bad physiological condition of yeasts cells and inappropriately chosen yeast separation technology.

Brewing recipe design is mainly based on brewer’s expertise, information available in catalogs and certificates of analysis (CoA’s). Hop schedule design and formulation has become an essential topic since hoppy craft beers took the scene. But how accurate is the flavor profile information provided in catalogs? How useful is the chemical composition profile information in CoA’s? Besides current research and tons of reported experiences, hops impact is still a mystery, and topics like biotransformation are black-boxes for brewers. In this study, nine single hopped beers were brewed, and a trained panel conducted sensorial beer analysis. Then, to asses hop impact, qualitative and process-related-quantitative beer characteristics were contrasted to find valuable correlations and trends between hop catalogs and final beers. Discrepancies with catalog qualitative data were reported. In addition to what is already described in the literature, here we describe how α-acids, linalool, myrcene, and geraniol (despite the classical use for these compounds) could predict positive and negative hop impact of nine different hop varieties on bitterness, flavor, and aroma, when they are applied in different brewing process steps. Also, with this pipeline we stand the basis of a tool to be improved, available for brewers, to better predict their brews and assess new hop varieties in real-life pilot brewing set ups.