Understand the choice
TDS describes the concentration of dissolved material in the beverage. Extraction yield estimates dissolved coffee mass relative to the dry coffee dose. With a suitable refractometer, an approximate yield is beverage mass multiplied by TDS percent, divided by dose.
Put it into practice
The calculation assumes a representative, correctly prepared sample and excludes misleading solids or crema readings. Espresso and filter protocols differ; the number should support tasting rather than replace it.
Keep the conversation useful
Share your actual recipe or experience, identify the coffee or equipment and explain what changed. A clear question with measurements makes the discussion easier for others to answer.