tags: [] - coffee/brewing - coffee/brewing/water - coffee/history aliases: - Hendon 2014 - Role of dissolved cations in coffee extraction - Hendon water research

Hendon Study¶

Tags: #coffee/brewing #coffee/brewing/water #coffee/history Aliases: Hendon 2014, Role of dissolved cations in coffee extraction, Hendon water research Related: Water in Coffee MOC | Magnesium in Coffee Water | Calcium in Coffee Water | Magnesium vs. Calcium | Water Standards Status: ✅ Complete

Overview¶

The Hendon Study refers to the 2014 research paper "The role of dissolved cations in coffee extraction" by Christopher H. Hendon, Lesley Colonna-Dashwood, and Maxwell Colonna-Dashwood, published in the Journal of Agricultural and Food Chemistry by the American Chemical Society. This study is the most influential scientific work on coffee water chemistry, establishing that the specific mineral ions in brewing water — particularly the comparison between magnesium and calcium — significantly affect the compounds extracted from coffee and consequently the flavour of the brewed cup. It provided the scientific foundation for the modern specialty coffee approach to water management.

Study Details¶

Authors: Christopher H. Hendon (computational chemist, University of Bath); Lesley Colonna-Dashwood (World Barista Champion 2014, Square Mile Coffee); Maxwell Colonna-Dashwood (Colonna Coffee, Bath)
Journal: Journal of Agricultural and Food Chemistry, American Chemical Society
Year: 2014
DOI: 10.1021/jf501687c
Methodology: Combined computational modelling (DFT — density functional theory) and empirical sensory evaluation; modelled the interactions between mineral ions and coffee solubles; validated computationally predicted extraction differences with sensory panels

Key Findings¶

Magnesium Extracts More Effectively Than Calcium¶

The study's central finding: at equivalent molar concentrations, Mg²⁺ extracts more flavour-relevant compounds from coffee than Ca²⁺. Specifically: - Magnesium produced higher concentrations of organic acids (citric, malic) and aromatic volatile compounds in the brew - Calcium extracted a different profile with lower overall efficiency for brightness-contributing compounds - The mechanism: Mg²⁺ has higher charge density (smaller ionic radius) → stronger electrostatic interaction with the polar functional groups on coffee's organic molecules → more effective dissolution into the aqueous phase

Bicarbonate Suppresses Coffee Acidity¶

The study confirmed the mechanism by which alkalinity (bicarbonate) suppresses coffee's organic acid character: direct chemical neutralisation (HCO₃⁻ + H⁺ → H₂O + CO₂), with experimental demonstration of the quantitative relationship between bicarbonate concentration and suppression of coffee acidity markers.

Water Hardness Matters, But Composition Matters More¶

Total water hardness (TDS) is insufficient as a quality metric — the composition of the dissolved minerals determines the extraction outcome. The same TDS from magnesium-dominant versus calcium-dominant water produces measurably different cups.

Impact on Specialty Coffee¶

The Hendon Study triggered a paradigm shift in how specialty coffee approached water: - Water recipe design moved from "use filtered water" to specific mineral targets - Magnesium as preferred hardness source became the standard in specialty water recipes (Barista Hustle Recipe, Third Wave Water, various barista competition water recipes) - Alkalinity measurement (KH titration) became standard practice in quality-focused cafés - Water chemistry as a competitive variable became recognised at barista competitions; WBC competitors began disclosing and managing water used in competition

The study was popularised through Colonna-Dashwood and Hendon's book Water for Coffee (2015), which brought the research to a general barista audience.

Key Facts¶

Published 2014, Journal of Agricultural and Food Chemistry; authors: Hendon, L. Colonna-Dashwood, M. Colonna-Dashwood
Central finding: Mg²⁺ extracts coffee flavour compounds more effectively than Ca²⁺ at equal concentration
Mechanism: higher charge density of Mg²⁺ → stronger interaction with coffee solute functional groups
Also confirmed bicarbonate's role in suppressing coffee acidity via direct acid neutralisation
Foundational study for modern specialty coffee water management and recipe development

References¶

Changelog¶

Date	Change
2026-04-28	Note created

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