What is the brew chart or Golden Cup standard?
The Brewing Control Chart — the SCA's 'Golden Cup' — is a two-axis diagram: EY on the x-axis (14 to 26 %) and TDS on the y-axis (0.8 to 1.8 %). At its centre, a rectangular sweet spot (EY 18-22 % / TDS 1.15-1.35 %) defines a balanced filter coffee per the SCA standard.
The Brewing Control Chart was designed in the 1950s by Ernest Earl Lockhart for the Coffee Brewing Institute, precursor to the SCAA and the SCA. The chart crosses two variables: concentration (TDS) and yield (EY). The ideal rectangle sits inside four labelled corners: high TDS + low EY = 'strong underdeveloped' (strong but sour); low TDS + high EY = 'weak bitter'; high TDS + high EY = 'strong bitter' (over-concentrated, over-extracted); low TDS + low EY = 'weak underdeveloped' (thin and sour).
The SCA ratified the 18-22 % EY / 1.15-1.35 % TDS window in 1995 for filter coffee, reaffirmed in 2017 at the SCAA-SCAE merger. Matt Perger modernised the visualisation in 2015 with the Barista Hustle 'coffee compass': same idea, wider axes (14-26 % EY, 0.8-2 % TDS) to cover espresso, French press and cold brew, with a moving target by method. The compass made it visual that espresso at 9 % TDS / 20 % EY is balanced, whereas a V60 at 9 % TDS would be undrinkable — the target shifts with the method.
In practice, the chart works like a diagnostic compass. Brew the coffee, read TDS (VST or Atago refractometer), calculate EY, plot the point. If it lands bottom-left, you have an under-extracted, over-diluted cup: tighten grind, raise dose or time. If top-right, an over-extracted, over-concentrated cup: open grind, dilute. Scott Rao stresses in 'The Professional Barista's Handbook' how this feedback loop pulls quality evaluation out of pure subjectivity.
In Belgium, the chart is taught in the opening module of specialty programmes (Antwerp Coffee Academy, Brussels Coffee Project, SCA Foundation and Intermediate Brewing). It hangs in most Brussels and Ghent roastery labs, printed A3 with a paper grid for daily trials. At the Belgian Barista Championship, being able to plot an espresso on a coffee compass is an implicit expectation of the sensory judges.
SCA brew chart zones and interpretation
| Zone | TDS / EY position | Typical taste | Correction |
|---|---|---|---|
| Ideal (Golden Cup) | 1.15-1.35 % / 18-22 % | Balanced, sweet, clean | Keep the recipe |
| Underdeveloped strong | 1.35 %+ / < 18 % | Strong but sour, salty | Tighten grind, keep ratio |
| Underdeveloped weak | < 1.15 % / < 18 % | Thin, sour, flat | Tighten + tighten ratio |
| Bitter strong | 1.35 %+ / 22 %+ | Concentrated, bitter, astringent | Open + extend ratio |
| Bitter weak | < 1.15 % / 22 %+ | Thin but bitter | Open + drop temperature |
| Nordic strong | 1.40-1.55 % / 21-22 % | Strong, sweet, dense | Outside Gold Cup but accepted |