Measuring Total Soluble Solids with Refractometers

Inline, process refractometer for beverage production.

Just as weight is expressed in pounds, the level of soluble solids in a solution is measured in degrees Brix (symbol °Bx).  The Brix scale is based on a solution of pure sucrose diluted with water. Adolf Brix first developed the Brix scale in the 1800s. For example, a 100 gram solution with a Brix 50 reading contains 50 grams of sugar (and other dissolved solids) and 50 grams of water.

Fruit juices, wine, nectars, and other beverages all contain soluble solids. Total Soluble Solids (TSS) refers to the total amount of soluble constituents of the juice, wine or other beverage. These are mainly sugars, with smaller amounts of amino acids, pectin, and organic acids. For example, approximately 85% of the total soluble solids of citrus fruit are sugars. Because sugar is the most abundant soluble solid, the Brix scale is used by the beverage industry in determining the sucrose equivalent of soluble solids in their products. The term "Brix" or "degrees Brix" is used interchangeably with % sucrose or % soluble solids by weight.

Refractometers are instruments that determine soluble solid concentration by evaluating the solution's refractive index. Changes in direction of a light beam passing through the solution correlate to the amount of dissolved solids in the solution. Basically, the higher the level of soluble solids in the solution, the greater the bending of the light beam. In large scale beverage plants, inline process refractometers are used to control quality and consistency by continuous monitoring of the soluble solid concentration.

For more information about measuring TSS and/or Brix in a commercial beverage production facility, contact Electron Machine by visiting https://www.electronmachine.com or calling 352-669-3101.