TDS
Definition
TDS (total dissolved solids) is how concentrated the drink is, usually read with a coffee refractometer. Filter coffee often lands near 1.2–1.5%; espresso 8–12%. TDS is strength. Extraction yield needs TDS and the brew ratio. Bypass water lowers TDS without changing how far the grounds were extracted.
Calculators that use this
Grind size & dialing in
TDS Target Calculator
Work backwards from dose, beverage yield and a target extraction yield to the TDS your refractometer should read. Strength is not extraction.
Grind size & dialing in
Espresso Extraction Yield Calculator
Compute extraction yield and brew ratio from refractometer TDS, basket dose and beverage mass. EY% = TDS% × yield / dose.
Water chemistry
Water Bypass Calculator
Add bypass water to a brewed batch to hit a lower target TDS. Beverage mass goes up; extraction yield of the grounds stays where it was.
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