Shelf life of confectionery
Sugar has an impact on the keeping qualities of confectionery.
Boiling a sugar solution to the point of over-saturation and subsequently cooling it down is the basis for manufacture of hard toffee. The keeping qualities of hard toffee can be limited.
Over time the sugar starts to crystallise. This crystallisation can be prevented by adding glucose syrup.
However, it is important to achieve the correct ratio of sugar to glucose syrup. If the content of glucose syrup is too high, the toffee gradually become more and more sticky.