Specialist supplier of scientific water analysis, beverage and laboratory test equipment

Let Science help to Quantify Coffee Quality

Written by Janice M on . Posted in Food & Beverage

coffee_manAre you disagreeing or struggling to decide on the flavour of different coffee samples? You can now measure the brix / concentration of coffee with the new PAL-Coffee. This allows you to express and control the acidity and bitterness.

Coffee fans the world over are in search of the “perfect cup”. One of the important characteristics of coffee is the mouth-feel. The same coffee beans can provide a different mouth-feel, depending of whether it is strongly brewed or weakly brewed. The mouth-feel of coffee is closely related to the yield.

Coffee baristas, developers and tasters can now enjoy supporting their work with PAL-Coffee assisted control.

What is the yield?

The yield refers to the amount of coffee extracted from the grounds. The yield is a numerical parameter and thus a consistent tool for remaking the same good flavour every time. The yield needs to be monitored whilst the recipe for a specific bean is being developed.

The yield alone cannot contain all the aspects of a coffee tasting. The sensory evaluation of coffee also includes characteristics such as the body, aroma, flavour and aftertaste. (You may be interested in reading Cupping Protocols by the Statistics & Standards Committee of the Specialty Coffee Association of America for guidelines.)

However, the yield is closely related to the acidity and bitterness and helps to quantify these important aspects of coffee flavour.

Typical Correlation of Yield*

  • Too low a yield = sour tasting coffee
  • Too high a yield = bitter-tasting coffee
  • Low brix = weak coffee
  • High brix = strong coffee
*The brix / concentration of coffee may not always be indicative of its yield.
Brix and Yield (with target value examples provided by Atago customers)

Brix and Yield (with target value examples provided by Atago customers)

Tips for Accurate Coffee Measurements:

  1. Zero-set the unit with room temperature water before measuring and after measuring. Both the meter and water should be acclimated at room temperature before measuring.
  2. Clean the prism thoroughly with cotton swabs after each measurement.
  3. The concentration of the coffee changes over the course of the extraction process. Gently stirring the coffee will even out the consistency and promote measurement stability.
  4. French press coffee: Pour the coffee into a cup and allow it to sit undisturbed for a while to allow particles to sink to the bottom. Avoid sampling from the oily surface.
  5. Espresso: Generally contains more particles than drip coffee. Measurement fluctuation by 0.5% is common.
  6. When cupping: Scoop out any floating grounds and oil thoroughly as they may cause unstable measurements.

Measurement fluctuation with the PAL-Coffee has been reported to be less than 0.1%. This is because the PAL-Coffee waits until the sample temperature is measured accurately to start measuring and produce accurate measurements.To ensure absolute accuracy, taking three consecutive measurements is recommended. The third reading will be fully stabilised.


coffee_app_logoMY COFFEE RECIPE App

MY COFFEE RECIPE App from Atago is available for purchase on the iTunes store. This allows you to record and track coffee testing information on an apple device..


  • Record your coffee concentrations – 10 records can be stored
  • Save measurement data as a new recipe
  • Record daily TDS and extraction testing results for each recipe
  • Convert daily testing results into graphs
  • Share recipes via email



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