TDS in Coffee
What total dissolved solids means in coffee brewing, how refractometers measure it and what TDS cannot tell you.
What TDS means
Total dissolved solids (TDS) in coffee describes the concentration of dissolved material in the brewed beverage, usually expressed as a percentage or parts per million.
Refractometers
Coffee refractometers estimate dissolved concentration using optical measurements. They are useful for repeatable recipe comparison but depend on calibration, sampling and appropriate coffee-specific methods.
TDS is not extraction yield
TDS describes concentration in the beverage. Extraction yield estimates how much soluble material was removed from the coffee dose. They are related mathematically but answer different questions.
Use TDS comparatively
A TDS value is most useful when interpreted with brew ratio, beverage mass and extraction yield rather than treated as a universal target.
Continue exploring
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Green coffee →Coffee chemistry
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Coffee chemistry →Coffee extraction
Connect grind, water, temperature, time, concentration and extraction.
Coffee extraction →Coffee Knowledge presents technical subjects as an educational reference. Terminology, grading systems and production practices can vary by country, producer, equipment and commercial context.