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.

  • DiFluid R2 Extract - Coffee TDS Refractometer

    DiFluid R2 Extract - Coffee TDS Refractometer

    DiFluid R2 Extract - Coffee TDS Refractometer

    Stop guessing whether your coffee is under-extracted.

    £175.95
    £175.95
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DiFluid

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Your guide to Refractometers

  • What does a refractometer actually measure?

    A coffee refractometer measures Total Dissolved Solids (TDS) - the percentage of your brew that is dissolved coffee rather than water. From TDS and your brew ratio you can calculate extraction yield: how much of the ground coffee actually ended up in the cup. Typical filter coffee lands around 1.15–1.45% TDS, while espresso is far more concentrated at roughly 8–12%. Most coffees taste balanced when extraction yield sits between 18 and 22% - and knowing your numbers is what lets you move them deliberately.

  • 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.

Other options to explore

  • Water Activity Meters

    Water Activity Meters

    Moisture says how much water. Water activity says whether it's a problem. Check every lot you store.

  • Coffee Moisture Meters

    Coffee Moisture Meters

    Know how a coffee will behave before it hits the drum. Moisture and density readings in seconds.

  • Roast Colour Meters & Analysis Equipment

    Roast Colour Meters & Analysis Equipment

    Roast colour tells you how the roast actually went. Measure it, track it, and reproduce your best batches.

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.

How does the R2 Extract compare to more expensive refractometers?

Devices like the VST Lab III and Atago PAL are the long-standing professional standards, with price tags to match. The R2 Extract reads TDS accurately enough for dialling in espresso and filter at a fraction of the cost, with app connectivity built in. If you're running a lab or need certified accuracy for research, the premium units earn their price. For brewing better coffee — at home or behind a bar — the R2 gives you the numbers that matter.