Why was the work done: The use of pellets was introduced as a method to reduce volume and increase shelf-life of hop plants (Humulus lupulus). There is no evidence that pellets retain better hop qualities compared to powder. The objective of this study was to compare the physical-chemical properties of hops in flower, powder, and pellet forms. How was the work done: Hop species (Cascade, Northern Brewer, and Comet) were analyzed in triplicate using chromatography, conductometric titration, steam distillation, and gravimetry, for essential oil content, alpha-acid percentage, and humidity, respectively. What are the main findings: A consistent reduction in essential oil content, alpha-acid percentage, and humidity was observed as the degree of hop processing increased from flower to powder to pellet. (p<0.0001, ANOVA and Tukey's post hoc test). Why is the work important: These results provide evidence that the pelleting process reduces key compounds like essential oils and alpha acids that contribute to hop quality for beer production when compared to the powder presentation. Eliminating the pelleting process could potentially reduce some production costs associated with hop processing. Pelleting requires additional equipment and energy, which contributes to overall production expenses.
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