Evaluation of Nonvolatile Chemistry Affecting Sensory Bitterness Intensity of Highly Hopped Beers

Abstract

The range of different nonvolatile constituents extracted from hops in highly hopped beers suggests that isohumulones may not be the sole contributor to beers' bitterness. Among brewers producing hop-forward beer styles, there is concern that the bitterness unit (BU) is no longer an accurate predictor of beer bitterness. This study examined factors within the beer matrix that influence sensory bitterness perception in highly hopped beers. Over 120 commercial beers were evaluated using sensory and instrumental techniques. Chemical analysis consisted of the BU via spectrophotometry, hop acids via high-performance liquid chromatography, total polyphenols via spectrophotometry, and alcohol content plus real extract via an Alcolyzer. Sensory analysis was conducted over two studies, and the beers' overall bitterness intensities were rated using a 0-20 scale. This study identified that the BU measurement predicts sensory bitterness with a nonlinear response, and it proposed an alternative approach to predicting bitterness based on isohumulones, humulinones, and ethanol concentrations. The study also revealed the importance of oxidized hop acids, humulinones, as a significant contributor to beer bitterness intensity.

Humulone Modulation of GABAA Receptors and Its Role in Hops Sleep-Promoting Activity

“…The Human Equivalent Dose (HED) based on body surface area for 10 mg/kg in mice is 0.81 mg/kg (Nair and Jacob, 2016). Noting that humulone solubility is 14 mg/L in beer and was detected up to 28 mg/L (Fritsch and Shellhammer, 2007), the dose of 10 mg/kg is comparable to a 60 kg human consuming 2 L of hopped beer with a humulone concentration of 24.2 mg/L (Hahn et al, 2018). Despite humulone did not alter the onset of sleep induced by ethanol, the evident increase in the duration of sleep could be attributed to the synergistic interaction with ethanol on native GABA A receptors as discussed above.…”

Impact of static dry‐hopping rate on the sensory and analytical profiles of beer

“…Al-though polyphenols were not measured in this study, it is expected that the extraction of hop polyphenols at the higher dry-hopping rates may have led to this deviation. Hahn et al (33) recently observed that the perception of bitterness intensity of hoppy beers is associated with primarily humulinone and isohumulone concentration. Therefore, although the sensory bitterness of these dry-hopped beers was not evaluated, it is clear that dry-hopping rate has a direct impact on the concentration of analytes that are important for the perception of bitterness in beer.…”

Insights into chemical and sensorial aspects to understand and manage beer aging using chemometrics

“…More recently, studies have compiled several possible aging indicators and their potential formation mechanisms (Baert et al, 2012;Vanderhaegen et al, 2006). In addition recent research has highlighted the sensory influence of changes on taste and mouthfeel caused by aging compounds (Hahn, Lafontaine, Pereira, & Shellhammer, 2018;Vrzal et al, 2019). These molecules possess chemically distinct functional groups such as aldehyde, ketone, ether, and ester moieties.…”