This article explores the accuracy and affordability of using a Brix refractometer compared to a more expensive Atago refractometer for measuring Total Dissolved Solids (TDS) in espresso. The author conducted experiments to compare the two methods and found that the cheaper Brix meter provided comparable results.
total hardness of 50-175 ppm CaCO3 (2,9-9,8 dH°)
carbonate hardness of 40-75 ppm CaCO3 (2,9-9,8 dH°)
total hardness should exceed carbonate hardness
pH of 6.5-8
carbonate hardness of 40-75 ppm CaCO3 (2,9-9,8 dH°)
total hardness should exceed carbonate hardness
pH of 6.5-8
Brew water containing low levels of both calcium ions and bicarbonate (HCO₃⁻) – that is, soft water – will result in a highly acidic cup, sometimes described as sour. Brew water containing high levels of HCO₃⁻ – typically, hard water – will produce a chalky cup, as the bicarbonate has neutralized most of the flavorsome acids in the coffee.
