Glucose syrup is a solution (up to 80%) of glucose (dextrose) in water. It is normally obtained by enzymatic hydrolysis of starch, which is a polymer of glucose. Starch from wheat, corn, potato or any other plant can be used for this purpose. The origin of the starch does not have to be labelled and can only be provided by the producer. However, due to new EU legislation on allergens, glucose syrup derived from wheat has to be labelled as such.

Glucose syrup is less sweet as normal sugar, but has several technological advantages in the food industry.