Optimization of cold brew coffee extraction variables through sensory evaluation by Q-graders
DOI:
https://doi.org/10.25186/.v21i.2412Abstract
Cold brew is a type of coffee beverage that has recently become popular worldwide, with a future global market for 2027 worth more than a billion dollars. There is no consensus among baristas, on the internet, or in scientific literature on how to prepare this type of brew. The ranges of extraction time (t), as well as water temperature (T) and coffee-to-water ratio (R) in published works reveal end products that are quite different from each other. In this study, a novel protocol for the quality evaluation of cold brew coffee was developed and different extraction conditions of the beverage were investigated, which were evaluated by coffee experts (Q-graders) in terms of eleven sensory attributes through quality scales. After a series of experimental design results, desirability functions were used to perform statistical optimization of sensory data. Extraction conditions leading to beverages of presumably superior quality were proposed with coffee-to-water ratio R=1:5 (w/v) and 22:43 h of infusion when brewed under refrigerated temperature (~5 °C) or 18:53 h of infusion under room temperature (~20 °C) water. Extraction conditions leading to supposedly inferior, or average-quality beverages were also proposed.
Key words: Coffee quality; cupping; desirability; Arabica coffee; central composite design.
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