Residual sugar in wine is classed as fermentable sugars present after fermentation and consist primarily of D-fructose and D-glucose.
To measure both of D-fructose and D-glucose use the D-Fructose/D-Glucose Assay kit (K-FRUGL) for the manual spectrophotometer format or the D-Fructose/D-Glucose Assay Kit (Liquid Ready Reagents) (K-FRGLQR) for the auto-analyser or microplate formats. These kits can generate either a single value for total residual sugars (D-fructose plus D-glucose) or individual values for both D-fructose and D-glucose.
Sucrose is made up of D-glucose linked through beta-1,2 to D-fructose and is sometimes added to wine as a sweetener.
To include sucrose in the measurement of total sugar use the Sucrose/D-fructose/D-Glucose (K-SUFRG).