---
type: Abbreviation
title: TDS — Total Dissolved Solids
description: Brew-strength measure — the proportion of dissolved coffee solids in
  the finished cup.
aliases:
- TDS
- Total Dissolved Solids
tags:
- coffee
- brewing
- measurement
resource: raw/brewing-science-notes.md
timestamp: '2026-07-16T15:03:02Z'
citadel_version: 0.3.0
---

Total Dissolved Solids (TDS) is the percentage, by mass, of dissolved coffee solids in a brewed cup — used to measure a brew's strength objectively rather than by taste alone.[^llm1]

The [Specialty Coffee Association](../organizations/specialty-coffee-association.md)'s "Golden Cup" standard targets a strength of about 1.15-1.35% TDS in the finished brew, with some references widening the pleasant band up to about 1.45%.[^s1] Espresso runs far more concentrated, around 8-12% TDS.[^s2]

The same measurement also applies to the brewing water itself, expressed in parts per million (ppm) of dissolved minerals rather than as a percentage: the SCA's brewing water target is about 150 mg/L (ppm) TDS, with a usable range of roughly 75 to 250 ppm.[^s3]

Cold brew is measured the same way, but as an undiluted concentrate before serving: [Cordwell Roastworks](../organizations/cordwell-roastworks.md)' locked house spec targets a concentrate TDS of 4.0-4.2%, well above a filter coffee's brewing-strength range because it has not yet been diluted to drinking strength.[^s4]

## See also
- [Coffee Brewing](../concepts/coffee-brewing.md)
- [Specialty Coffee Association](../organizations/specialty-coffee-association.md)
- [Cordwell Roastworks](../organizations/cordwell-roastworks.md)
- [EY — Extraction Yield](ey-extraction-yield.md)

## Sources
[^s1]: [raw/brewing-science-notes.md](../../raw/brewing-science-notes.md), § The SCA Golden Cup numbers — brewed-coffee strength target (ingested 2026-07-16)
[^s2]: [raw/brewing-science-notes.md](../../raw/brewing-science-notes.md), § Espresso vs. filter — the two ends of the same dial — espresso TDS (ingested 2026-07-16)
[^s3]: [raw/brewing-science-notes.md](../../raw/brewing-science-notes.md), § Water chemistry — the invisible ingredient — brewing water TDS target (ingested 2026-07-16)
[^s4]: [raw/cold-brew-notes.md](../../raw/cold-brew-notes.md), lines 108-113 — locked cold-brew concentrate TDS target (ingested 2026-07-16)
[^llm1]: LLM - model knowledge, not from a raw file (added 2026-07-16)
