Refractometers

Refractometers

Refractometers bring lab-grade precision to coffee brewing. By measuring Total Dissolved Solids (TDS), they help you understand how much of the coffee has been extracted into the cup – giving you the data to fine-tune recipes and brew more consistently. Used by baristas, roasters, and quality control teams, they’re a valuable tool for anyone chasing better coffee through better measurement.

  • What does a coffee refractometer measure?

    A coffee refractometer measures Total Dissolved Solids (TDS) – the percentage of dissolved compounds in a brewed coffee sample. With this TDS value, and knowing your dose and final beverage weight, you can calculate extraction yield. This helps you understand how much of the coffee’s soluble content has made it into the cup – and whether you’ve under- or over-extracted.

  • Who uses them – and why?

    Refractometers are widely used in professional settings – by baristas for espresso calibration, by roasters for QC and sample evaluation, and by trainers for education. Increasingly, they’re also used by home brewers looking for more consistency and clarity in their brews. The tool gives users a way to quantify what’s happening in the cup, rather than relying on taste alone.

  • How do they help improve brewing?

    By measuring TDS and calculating extraction yield, a refractometer helps you adjust brewing variables with intent. For example, if your extraction is low, you might grind finer or extend brew time. If it’s too high, you may reduce contact time or coarsen the grind. The result is more consistency across brews, better understanding of how changes impact flavour, and ultimately a more controlled approach to brewing.

Your questions, answered

Is a refractometer only for espresso?

Not at all. Refractometers work for any brew method – espresso, filter, immersion, or cold brew. You just need a clear sample to measure.

Do I need special software to use it?

Some models come with their own software or apps to calculate extraction yield. Others give you the TDS reading, and you can do the calculation manually using your dose and yield.

How accurate are refractometers?

Very accurate when used properly. Cleanliness, sample clarity, and temperature all affect results, so following the instructions closely makes a big difference.

Can beginners use a refractometer?

Yes – it might seem technical at first, but they’re easy to use once you’ve run through a few brews. They’re especially useful if you’re experimenting or want to troubleshoot consistency.