Golden Syrup - Production

Production

Originally, in cane sugar refining, golden syrup was made from those sugars that failed to come out of solution at the crystallization stage, but an equivalent product may be made from beet sugar by processing a sucrose solution to break down a proportion of the disaccharide, converting it into the monosaccharides glucose and fructose. This may be done by acid hydrolysis or by adding an enzyme, invertase.

Typically in acid hydrolysis, the disaccharides are split by hydrochloric acid, resulting in a solution which is acidic; neutrality is restored by the addition of lye, which is sodium hydroxide. As a result, syrup made this method contains some common salt, sodium chloride.

The glucose and fructose produced are more water-soluble than the original sucrose. As a result, golden syrups are less likely to crystallize than a pure sucrose syrup. The high fructose content gives the syrup a taste sweeter than that of an equivalent solution of white sugar; when substituting golden syrup for white sugar, about 25% less golden syrup is needed for the same level of sweetness.

The term invert comes from the method used for assessing sugar syrups. The plane of linear polarised light passed through a sample of pure sucrose solution is rotated to the right. As the solution is converted to a mixture of sucrose, fructose and glucose, the angle of rotation reduces, through zero and then increases in the opposite direction, thus the direction appears to have been inverted compared to light passed through the sucrose solution.

Lyle's golden syrup is a partially inverted sugar syrup. It consists of glucose and fructose syrup produced by inversion, which has been blended with the original sucrose syrup in a proportion that creates a thick mixture which does not crystallize.