Effects of grind size and brew time upon sensory traits, consumer likability and antioxidant activity of Arabica cold brew

This study examined effects of grind size (n = 3; 0.65, 1.15, 1.65 mm) and brew time (n = 3; 18, 24, 30 h) on the sensory traits, consumer likability and antioxidant activity of cold brew coffee (brewed at 4 degrees C). Total dissolved solids were measured to evaluate extraction efficiencies. The finest grind size demonstrated significantly greater antioxidant activity than the other samples, but grind size was not a significant factor for eighteen of the nineteen assessed sensory traits nor for hedonic assessments of appearance, flavour or overall likability. Notably, 24 h brew time samples showed consistently lower magnitudes of sensory traits, hedonic assessments and antioxidant activity than those brewed at 18 or 30 h. This effect was significant in predictive modelling and not explainable by magnitudes of dissolved solids (which increased with brew time). Findings demonstrate substantial nonlinear relationships between processing time and cold brew attributes.

Automated summary

This study found that grind size significantly affects the antioxidant activity of cold brew coffee, while brew time has important effects on sensory traits, consumer likability, and antioxidant activity. Notably, samples brewed for 24 hours showed lower sensory traits and antioxidant activity compared to those brewed for 18 or 30 hours.