R2 Extract Coffee TDS Refractometer

The object

R2 Extract measures total dissolved solids across a stated 0–30% range, covering both brewed coffee and espresso. Its open measurement well and large CMOS sensor are designed to reduce the handling required by conventional lid-equipped refractometers.

Bluetooth links readings to DiFluid's CoffeeOS tools, where dose and beverage mass can turn TDS into an extraction estimate. Espresso samples may still benefit from filtering because oils and suspended material can affect optical readings.