TDS stands for Total Dissolved Solids. It measures the concentration of dissolved solids in coffee, such as sugars, acids, oils, and bitter compounds.
Quick Answer: TDS means total dissolved solids, a measurement of dissolved material in brewed coffee. It can help compare strength, but it does not replace taste. Use it with brew ratio, extraction, water, and sensory evaluation.
For the extraction basics behind TDS, compare this guide with What Is Coffee Extraction?.
What is TDS in Coffee?
Simply put, TDS indicates the proportion of coffee solids dissolved in your brewed beverage, expressed either as a percentage (%) or parts per million (ppm).
Example:
- A pour-over coffee with a TDS of 1.30% means that 1.3% of the coffee is extracted solids, while the remaining 98.7% is water.
Why is TDS Important?
TDS helps quantify how much coffee material is dissolved, which is crucial for controlling flavor and consistency:
|
TDS Value |
Perceived Taste & Texture |
Notes |
|
~1.15–1.35% |
Typical pour-over concentration |
Clean, distinct layers |
|
~1.4–1.5% |
Slightly denser pour-over |
Fuller, richer mouthfeel |
|
~8–12% |
Espresso concentration |
Strongly concentrated, intense flavor |
How to Measure TDS?
You measure TDS with a specialized instrument called a Refractometer (or TDS meter):
- VST Refractometer (Industry standard)
- DiFluid R2 (Cost-effective, also calculates extraction yield)
- Atago PAL-Coffee (Renowned Japanese brand)
Relationship Between TDS and Extraction Yield (EY)
- TDS: Measures coffee's strength or concentration.
- Extraction Yield (EY): Indicates the total percentage of coffee solids extracted from the coffee grounds.
Calculation of Extraction Yield:
Troubleshooting with TDS & EY:
Adjust your brewing based on TDS readings:
- High TDS → Coffee tastes overly bitter or strong:
- Solution: Coarser grind, faster brewing flow.
- Low TDS → Coffee tastes weak or thin:
- Solution: Finer grind, increase extraction time.
Understanding TDS allows you to systematically refine your coffee brewing process, consistently achieving optimal flavor profiles.