The refractometer is used to measure both °Brix and S.G (specific gravity) depending on which axis the reading is taken. In the brewing industry, it is used during the brewing process to measure the wort extract at any given time.
Operation:
Once the apparatus has been zero’d with distilled water (using the adjustment screw), a drop of sample is placed on the reading (daylight) plate, and the cover closed gently while avoiding bubbles from forming. The apparatus is then pointed towards a source of light while the operator looks through the eyepiece to observe the reading. There is a focus adjustment as well if the reading is unclear.
The range of this specific refractometer is 0-32°Brix. It is important to note that the reading given by the refractometer is at 20°C. If the sample transferred onto the apparatus is at a temperature other than this, a correction needs to be made – These correction tables can be found online.
On the technical side:
1 °Brix represents a 1g Sucrose in 100g solution. The °Brix obtained provides an indication of the mass percentage of dissolved solids. In brewing, the °Brix that is read represents the mass percentage extract in the wort. This result can be used to determine the efficiency of one’s mashing regime, seeing as the mass of extract obtained can be compared to the total grist mass.
