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VST LAB Coffee III Refractometer

Barty Single Origin

Regular price $1,426.61

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The VST LAB Coffee III Refractometer is a tool that has been used for measuring coffee & espresso Total Dissolved Solids (TDS) to understand the efficiency and quality of brewing through extraction. 

VST Labs have advanced the Refractometer with the latest fourth-generation that provides laboratory precision that comfortably fits into the palm of your hand. The Lab III Refractometer has an expected accuracy of +/- 0.02% and worst case precision of +/- 0.1%.

Designed for the rapid and accurate calculation of coffee concentration within a sample, an automatic temperature compensation has been programmed to automatically correct for temperature within the range of 15-40cº. 

Advanced Sapphire Optics backed by a 1024 Element Detector Array boost precision and improve accuracy to +/- 0.03% in the Filter coffee sample range and +/- 0.05% in espresso sample range. The super fast reading will automatically average multiple measurements and than display the resulting TDS as a decimal reading, easily converted to a percentage out of 100%.

Using the built-in Auto ranging TDS Scale you can explore and understand the nuances of flavour vs strength vs extraction and begin to catalogue effective ways to make better tasting coffee.

An ambient light shield and evaporative cover protect the stainless steel sample well and optics. Intended for use in commercial settings, the VST Lab Refractometer adopts a durable rugged rubber armour jacket to sustain the tough cafe and kitchen environment. 

With the added option of VST CoffeeTools Software, (Window or MacOS) you'll gain access to further tools to be used alongside the VST LAB Coffee III Refractometer  to calculate the extraction yield and other variables.

VST LAB Coffee III Refractometer  FEATURES

TDS Analysis – Discover the extraction yield of brewed coffee using Light Refraction.

Sapphire Optics – With extreme surface hardness and scratch resistance.

Multiple Measurements – Averaging out the TDS over several samples taken.

Auto-Ranging – From Filtered Coffee to Espresso range of 0.00-20.00%

Temperature Stable – Automatic Temperature Compensation provides accurate results regardless of surrounds.

Smart Zero Set – Using distilled water ensures precision and accuracy of reading.

Durable Cover – It will protect the Refractometer in harsh environments.


  • VST LAB Coffee III Refractometer


Coffee Espresso Coffee & Espresso
Unit of Measurement % TDS
Range 0.00 - 9.99 0.00 - 20.0 0.00 - 20.00
Resolution 0.01% 0.1% 0.1%
Precision +/- 0.02% +/- 0.1% +/- 0.03%
Accuracy +/- 0.05% +/- 0.1% 0.00 - 4.99 – +/- 0.05%

5.00-20.00% – +/- 0.10%

Prism Material Sapphire
Well Material Stainless Steel
Detector 1024 Elements
Temperature Range 15 to 40ºc
Sample Volume 0.3ml
Measuring Time <2 Seconds
Power 2 x AAA Batteries
Battery Life >4,000 Readings
Dimensions (mm) (L) 145 x (W) 75 x (D) 37
Weight 250g

Note: This is just the refractometer. Included software is available to gain access to further calculations of extraction yield and other results. The VST LAB Coffee III Refractometer only, measures % TDS.


Available Styles

  • With Software - VST LAB Coffee III Refractometer
  • Without Software - VST LAB Coffee III Refractometer

Check out how to use the VST LAB Coffee III Refractometer in the Video Below: