The extensive use of pesticides in agriculture has led to the presence of their residues in soil, water sources, and crops. Among these, the plant growth regulators chlormequat and mepiquat are commonly employed to regulate plant growth. The European Union has established maximum residue limits (MRLs) for different types of cereal (barley 7 mg/kg for chlormequat and 4 mg/kg for mepiquat). However, the extent to which these compounds are transferred from raw brewing materials into beer remains poorly understood, and no regulatory limits currently exist for their concentrations in beer. This study aimed to develop and validate a rapid, cost-effective, and straightforward analytical method for the simultaneous determination of chlormequat and mepiquat in beer. A Dilute and Shoot strategy was evaluated: degassed beer samples were diluted with acetonitrile and analysed using a Waters Acquity UPLC system coupled with a XEVO TQ-S micro mass spectrometer, including electrospray ionization (ESI). Chromatographic separation was achieved using an isocratic elution on a Kinetex (R) 1.7 mu m (100 & times; 2.1 mm) HILIC column. Method performance was assessed in terms of linearity, detection and quantification limits, precision, and accuracy. Recoveries were 89% for chlormequat and 84% for mepiquat, with relative standard deviations (RSDs) not exceeding 4%. A total of 90 beer samples were analysed, revealing contamination in 86% of samples, with concentrations ranging from 0.1 to 28.9 mu g/L.
The alpha acids content of Czech hops from the 2025 harvest was evaluated using pre-harvest forecasts, harvest forecasts and final analytical data obtained from more than 3,300 commercial and farm samples processed by three independent laboratories. Weather conditions during the 2025 growing season differed from those in 2024, mainly because of lower summer temperatures and lower precipitation totals during April-September, while September rainfall was high but had only a limited effect on harvest results. In the Saaz variety, the final alpha acids content reached 3.52% w/w in the & Zcaron;atec region, 3.33% w/w in the & Uacute;& scaron;t & ecaron;k region, and 3.23% w/w in the Tr & scaron;ice region, i.e. values higher than those recorded in the preceding three crop years and closer to the long-term typical range for this variety. Among the Czech hybrid varieties, the highest alpha acids contents were observed in Agnus, Vital, and Rubin, while Sl & aacute;dek, Premiant, Kazbek, Saaz Late, Saaz Special, and Saaz Shine also showed commercially relevant levels. The total production of alpha acids in the Czech Republic in 2025 was estimated at 297.8 t, with Saaz accounting for 59% of total alpha acid production despite occupying 82.1% of the harvested area. The results confirmed the dominant role of weather conditions, but also highlighted the effects of stand age, planting material and local environmental conditions on the final alpha acids content.
Pre-harvest sprouting represents a serious agronomic risk in spring barley cultivation, particularly in years characterised by increased air humidity and more frequent rainfall during the pre-harvest and harvest periods. This study evaluates the risk of pre-harvest sprouting in selected spring barley varieties tested in the Czech Republic in 2023. Pre-harvest sprouting intensity was assessed using the Falling Number and Rapid Visco Analyser methods. The results indicate that the site had a dominant effect on pre-harvest sprouting (approximately 70%), while the variety influenced pre-harvest sprouting by 16-18%. Astrong correlation (r = 0.978***) was found between the values obtained by the Falling Number and Rapid Visco Analyser methods, confirming that both methods yield consistent results. The LG Tuplak variety showed a low risk of pre-harvest sprouting. The Kimberly, RGT Proxima, and Guzel varieties had a high risk of pre-harvest sprouting. The study highlights the importance of selecting suitable varieties and growing sites as key factors in minimising the risk of grain pre-harvest sprouting.
Pre-harvest sprouting represents a serious agronomic risk in spring barley cultivation, particularly in years characterised by increased air humidity and more frequent rainfall during the pre-harvest and harvest periods. This study evaluates the risk of pre-harvest sprouting in selected spring barley varieties tested in the Czech Republic in 2023. Pre-harvest sprouting intensity was assessed using the Falling Number and Rapid Visco Analyser instruments. The results indicate that the site had a dominant effect on pre-harvest sprouting (approximately 70%), while the variety influenced pre-harvest sprouting by 16 and 18%. A strong correlation (r = 0.978***) was found between the values obtained by the Falling Number and Rapid Visco Analyser instruments, confirming that both methods yield consistent results. The LG Tuplak variety showed a low risk of pre-harvest sprouting. The Kimberly, RGT Proxima, and Guzel varieties had a high risk of pre-harvest sprouting. The study highlights the importance of selecting suitable varieties and growing sites as key factors in minimising the risk of grain pre-harvest sprouting.
Two new Czech hop cultivars, Art and Uran, were developed within the national hop breeding program of the Czech Republic to improve drought tolerance while maintaining high brewing quality. The cultivars were evaluated for agronomic performance, chemical composition, and sensory properties in both hops and beer. Drought tolerance was assessed by measuring photosynthesis (A) and transpiration (T) rates under water stress using a portable photosynthesis system, complemented by visual evaluation. Art showed the highest drought resistance, maintaining photosynthetic activity and minimal stress symptoms even after ten days without irrigation. The chemical composition of both cultivars was stable. Art contained on average 5.8% w/w of alpha acids with a balanced alpha/beta acid ratio of 1.07, while Uran reached 11.9% w/w and a ratio of 2.34, confirming its classification among bitter hops. Art expressed a fine aroma–flavour character with citrusy and herbal tones, whereas Uran combined bitter and flavour attributes with woody and spicy notes. In brewing trials, both cultivars effectively transferred their aroma into beer. Art produced a delicate bitterness with fruity–herbal notes, while Uran yielded a moderate bitterness with hoppy–woody tones. Both represent promising, drought-tolerant cultivars expanding the diversity of Czech hops.
