Start with extraction and TDS when your coffee is simultaneously sour, weak, bitter or unpredictably strong. The guide distinguishes beverage concentration from extraction yield and provides a weighed 20 g dose example and a four-brew experiment. You can follow its diagnostic workflow without buying a refractometer.
Start with water chemistry when the same coffee behaves differently after you change tap water, filter cartridges or bottled water. It explains why hardness and alkalinity should not be mixed up, how to read a water label and how to compare two waters safely. Espresso-machine owners should check their manufacturer's water specifications before changing mineral composition.
Our practical reading sequence
Choose the symptom or question, not an abstract “perfect coffee” score.
Read the relevant explanation and note which statements are definitions versus suggested experiments.
Change one factor at a time and write down the result. If there is no improvement, return to the baseline.
These are educational explainers, not laboratory reports. We distinguish worked arithmetic examples from measured results and identify outside references where they are helpful.
