Brix (°Bx) is a unit of measure that has been traditionally used in the wine, sugar, fruit, and honey industries to estimate the sugar (sucrose) or water soluble content (on a percent by weight basis). Forages are composed of many soluble and nonsoluble compounds. Water-soluble compounds (WSC) could include sugars (sucrose and fructans), oils, minerals, pectins, acids, proteins, lipids, amino acids, tannins, etc. Download the PDF above.