Understanding TDS (Total Dissolved Solids) in Coffee

TDS stands for Total Dissolved Solids. It measures the concentration of dissolved solids in coffee, such as sugars, acids, oils, and bitter compounds.

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:

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.