Analysis and prognosis of bitter acids content in Czech hop varieties – year 2020 and long-term comparisons and trends

Alexandr Mikyška,Klára Belešová,Jana Tichá

doi:10.18832/kp2021.67.474

Alexandr Mikyška, Klára Belešová + Show 1 more

Open Access

https://doi.org/10.18832/kp2021.67.474

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Abstract

The article deals with the harvest forecast of the content of bitter acids in Czech hop varieties harvested in 2020. This is presented in the context of long-term trends in the content and composition of bitter acids analogues and the stability of the varietal characteristics in the aforementioned harvest. This analysis is usually available at the end of the calendar year. 180 hop samples were analysed using EBC 7.7 (HPLC) method. The α-acids content in the most important variety of Saaz (3.65% in dry matter) was 12.8% rel. higher than in the 2019 harvest and 4.2% rel. higher than the 28-year average. The α-acids content in Saaz Late (3.23%), Sladek (7.9%), Kazbek (6.4%) and Agnus (12.4%) was significantly higher than both the long-term averages for the varieties and the harvest of 2019. The Premiant (8.0%) variety was close to the long-term average. The ratio of α-/β-acids, the relative content of cohumulone and the relative content of colupulone were consistent with long-term averages of the tested varieties. It was confirmed that the harvest forecast provides timely information on the α-acids content of the given harvest, the results being in good agreement with the values of the final evaluation of all harvested hops.

Highlights

This study presents a harvest forecast of the content of αand β-bitter acids in significant Czech hop cultivars from the harvest of 2020 in the context of long-term trends in the content of hop resins in Czech hops
In 2004, the Research Institute of Brewing and Malting (RIBM) began the evaluation of other Czech hop varieties called Sládek and Premiant which are important for domestic breweries
The average content of α- bitter acids in the hop samples examined from the Žatec area was 3.59% (3.25% in the original)

Summary

Introduction

This study presents a harvest forecast of the content of αand β-bitter acids in significant Czech hop cultivars from the harvest of 2020 in the context of long-term trends in the content of hop resins in Czech hops. The evaluation of the α- and β-bitter acids of the harvested hops at the Research Institute of Brewing and Malting (RIBM) is carried out yearly and has been done since 1950. The values provide a harvest prediction based on the analysis of 180–190 hop samples. The evaluation of the whole harvest for all the purchased batches of hops was performed by Chmelarstvi, cooperative Žatec and the Hop Research Institute, where both institutions used the lead conductance value. In 2004, the RIBM began the evaluation of other Czech hop varieties called Sládek and Premiant which are important for domestic breweries. In 2015 the assessment of the aroma variety Saaz Late started. The last variety was recommended by the RIBM for beer production according to PGI Czech Beer in 2013 (Mikyška et al, 2013)

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