Glucose syrup and corn syrup
Starch broken down into a syrup that resists crystallising — bought for what it stops happening rather than for sweetness.
Also called corn syrup (US); liquid glucose (UK); glucose syrup vs corn syrup (INTERNATIONAL); light corn syrup (US)
Glucose syrup is made by breaking starch down into shorter sugars. Corn syrup is glucose syrup made from maize starch; in Britain the same product is usually sold as liquid glucose and made from wheat. For baking purposes they are the same class of ingredient.
IT IS BOUGHT FOR AN ANTI-CRYSTALLISATION EFFECT. A syrup containing a mixture of sugar types crystallises far less readily than one containing sucrose alone, because the different molecules interfere with each other’s ability to form an ordered lattice. That is why it appears in caramels, fudge, icings, sorbets and anything else where a grainy texture is the failure mode.
IT IS LESS SWEET THAN SUGAR, not more. Glucose is perceptibly less sweet than sucrose, so replacing sugar with it reduces sweetness while keeping bulk and moisture — the opposite of what many people assume.
HIGH-FRUCTOSE CORN SYRUP IS A DIFFERENT PRODUCT and is not what a baking recipe means by corn syrup. It is enzymatically converted to raise its fructose content and is an industrial sweetener rather than a domestic baking ingredient. BakeHQ notes the distinction because the names are close enough to cause real confusion, and takes no nutritional position on either.
GOLDEN SYRUP IS NOT A SUBSTITUTE FOR IT IN CONFECTIONERY, though it is often suggested as one. Golden syrup is an invert sugar syrup with its own flavour and colour; it resists crystallisation too, but it is not neutral and it browns differently.
What changes if it is left out
Where it is preventing crystallisation, the honest alternatives are an acid — a little lemon juice or cream of tartar inverts some of the sucrose during cooking and achieves a similar effect — or golden syrup, accepting its flavour and colour. Plain sugar syrup on its own will crystallise.
Derived from the crystallisation mechanism described above. No quantities are given because they depend on the cooking temperature the recipe reaches.
RecordedFollows from evidence recorded elsewhere on BakeHQ
Related
Compared in
One side of the comparison.
What it does
Moisture retention
Holds water and keeps a confection soft.
Browning contribution
Browns readily, which is why it is in so many caramels.
Commonly confused with
Both resist crystallising; only one of them is neutral in colour and flavour.