Essential oils in Czech hop varieties

Abstract

Czech hop varieties were evaluated as part of maintenance breeding. The evaluation was performed in a single location between 2011 and 2020. The average weight of hop essential oils (HEOs) is 0.43 to 2.28% w/w. The Saaz, Saaz Brilliant, Mimosa, Saaz Shine and Saaz Comfort hop varieties have a low amount of HEOs. Their maximum content of these compounds amounts to 1.1% w/w. The average proportion of myrcene is between 23.42 and 45.14% rel. Only the Agnus, Vital and Boomerang hop varieties have the maximum myrcene proportion above 50% rel. The average share of caryophyllene ranges between 6.19 and 13.15% rel. Saaz Late has a broad range of caryophyllene percentage – from 5.39% rel. to 15.53% rel. The average percenatge of farnesene is between 0.14 and 16.91% rel. Only the Saaz Comfort and Saaz Shine hop varieties have the maximum farnesene share above 20% rel. The average humulene content has a very broad range between 2.23 and 35.79% rel. The Vital, Mimosa, Gaia and Saaz Comfort hop varieties are in a group with a low humulene percentage, which is clearly different from other hop varieties. The average share of selinenes ranges broadly from 0.97 to 33.56% rel. Mimosa differs from the before mentioned varieties with its proportion of selinenes between 23.08 and 43.75% rel. The aim was to characterize and compare Czech hop varieties in terms of content and composition of HEOs.

Variability and stability of essential oil composition in Ukrainian hop varieties

“…This aligns with the outcomes of our own research, which revealed the lowest oil content in hop varieties of the Saaz type, specifically Klon 18 and Zlato Polissya, where oil content ranged from 0.40 to 0.78 ml/100 g of dry hop cones. The average values we obtained for these varieties, 0.51 and 0.55 ml/100 g of dry hop cones, respectively, closely approach the lower bounds of the values reported in their passport data, which indicate an oil content range of 0.4-0.9 ml/100 g. Similarly, according to the Atlas of Czech hop varieties (Nesvadba et al, 2012), the essential oil content of Saaz varieties is reported to range from 0.4 to 0.8 ml/100 g of dry hops, consistent with the observations made decade later (Nesvadba et al, 2021). Furthermore, these Czech hop varieties are characterized by their high farnesene content, exceeding 20%, making them highly coveted among brewers for their aroma properties.…”

“…As reported by Czech scientists (Nesvadba et al, 2021) the fine aroma hop varieties of the Saaz type, such as Saaz, Saaz Brilliant, Saaz Late, Saaz Shine, and Saaz Comfort, exhibit notably low levels of essential oil content, ranging from 0.43 to 0.83 ml/100 g of dry hops. This aligns with the outcomes of our own research, which revealed the lowest oil content in hop varieties of the Saaz type, specifically Klon 18 and Zlato Polissya, where oil content ranged from 0.40 to 0.78 ml/100 g of dry hop cones.…”

“…In American hop varieties like Cascade, Amarillo, Citra, and Simcoe, myrcene content typically ranges from 50% to 70% (Ting et al, 2017). European hop varieties, on the other hand, exhibit lower myrcene content, falling within the 20% to 40% range (Nesvadba et al, 2021). Myrcene contributes to a range of aroma properties, often described as green and hoppy with hints of pine and citrus, influencing modern brewing techniques like "dry hopping" (Hauser et al, 2019;Rettberg et al, 2018;Nance et al, 2011).…”

“…Rising temperatures and a lack of precipitation, particularly during the essential oil synthesis phase, are key environmental parameters that can impact the stability of hop varieties. In recent years, increased temperatures and reduced precipitation have adversely affected hop cultivation (Krofta et al, 2019;Nesvadba et al, 2021). Acknowledging this challenge, a research project titled "Application of New Hop Varieties and Genotypes Resistant to Drought in Hop Growing and Beer Brewing" (Nesvadba et al, 2021) was initiated in the Czech Republic in 2021 to explore and utilize new hop genotypes that exhibit resistance to drought conditions, reflecting the industry's commitment to adapting to changing environmental conditions while ensuring stable beer quality.…”

“…The quantity and composition of essential oils are influenced by various factors, including cultivation practices, fertilization methods, and weather conditions. However, the genetic characteristics of hop varieties play a predominant role in determining the quality and composition of HEO, making essential oil analysis valuable for hop variety identification and certification (Nesvadba et al, 2021;Olšovská et al, 2016).…”