Scientists Develop Quicker Test to Measure Coffee Quality
Researchers have developed a quick, convenient test to assess the quality of black coffee, giving baristas and scientists a clearer view of flavor without complex laboratory work.
Boumbaugh and others. show that cyclic voltammetry can be used without any additional sample preparation to directly measure the strength of a coffee beverage and, separately, the dark color of roasted coffee. Image credit: Sci.News.
Existing methods for evaluating coffee typically rely on tasting panels or indirect measurements, such as estimating the amount of dissolved material in a sample.
However, these methods cannot distinguish chemical differences caused by roasting level or brewing choices.
Other laboratory techniques can identify individual molecules, but they are slow, expensive, and often impractical for routine use.
“Since the 1950s, the coffee industry has sought quantitative methods to assess beverage quality beyond those informed by sensory panels,” said University of Oregon researcher Christopher Hendon and colleagues.
“Meanwhile, a litany of research on the subject has revealed that the concentration of the beverage and the color of the roasted beans are the two primary and independent factors that dictate the sensory perception of coffee.”
“Bean color is easily determined spectrophotometrically, while the most widely used technique for measuring solvated coffee concentration relates the refractive index of the beverage to an effective concentration via an empirically derived polynomial.”
Researchers propose a new method to quickly assess the strength of black coffee using an electrochemical test called cyclic voltammetry.
The test involves applying a voltage and measuring the current transmitted as the coffee reacts to the electric field, which helps isolate differences in strength and roasting.
In their study, the scientists observed a linear relationship between the strength of the drink and the total electrical charge, with these signals also getting weaker as the roast of the samples became darker.
This weakening is attributed to roast-dependent molecules, including caffeine, which adhere to the platinum electrode during measurement.
The methods were validated by comparison with color and flavor descriptions from the quality control process of a UK-based roastery.
“This test could help distinguish batches of brewed coffee that appear identical and have similar dissolved solids values but differ in flavor,” the authors said.
“The results suggest that this test could provide a sensitive and reliable way to assess coffee composition, complementing existing tools used by the industry.”
The team’s work was published in the journal Natural communications.
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RE Bumbaugh and others. 2026. Direct electrochemical assessment of black coffee quality by cyclic voltammetry. Nat Common 17, 3618; doi: 10.1038/s41467-026-71526-5
