Scientists have developed a rapid, practical test for assessing the quality of black coffee, allowing baristas and researchers to better understand flavor profiles without the need for complex laboratory analysis.
Bamboo et al. demonstrate that cyclic voltammetry can directly measure the strength of coffee beverages and the degree of coffee roasting, without needing additional sample preparation. Image credit: Sci.News.
Traditional methods for evaluating coffee often rely on subjective tasting panels or estimations of dissolved substances in a sample.
Unfortunately, these methods may not accurately reflect chemical differences arising from varying roasting levels or brewing techniques.
While existing laboratory methods can identify individual molecules, they tend to be time-intensive, costly, and impractical for everyday use.
“Since the 1950s, the coffee industry has sought quantitative methods to evaluate beverage quality that extend beyond sensory panel insights,” noted Christopher Hendon, a researcher at the University of Oregon, along with his team.
“Research has shown that the strength of the coffee and the roasted bean color are two key, independent factors that influence coffee flavor.”
“While bean color can be easily analyzed through spectrophotometry, the most common method for measuring coffee concentration relates the beverage’s refractive index to effective concentration using an empirically derived polynomial.”
Researchers are now proposing a novel method to efficiently assess black coffee strength using an electrochemical test called cyclic voltammetry.
This technique differentiates strength and roast variations by applying voltage and monitoring the current flowing through the coffee in response to the electric field.
The scientists found a linear correlation between beverage strength and total electric charge, with signals decreasing as the roast of the sample darkened.
This reduction is linked to roast-dependent molecules, like caffeine, sticking to the platinum electrode during measurements.
The method’s validity was confirmed by comparing it with color and flavor descriptions from a UK-based roastery’s quality control process.
“This electrochemical test could effectively differentiate between batches of brewed coffee that appear similar and have comparable dissolved solids measurements but differ significantly in flavor,” the authors stated.
“The findings suggest that this approach may become a sensitive and reliable method for assessing coffee composition, complementing current tools in the industry.”
The team’s study is published in the journal Nature Communications.
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Bamboo et al. 2026. Direct electrochemical assessment of black coffee quality using cyclic voltammetry. Nat Commun 17, 3618; doi: 10.1038/s41467-026-71526-5
Source: www.sci.news
