What it does
Granules take up water and swell on heating, the structure inside them melts, and viscosity develops. That is gelatinisation. On cooling, the chains begin to reassociate, which builds set and, over time, causes retrogradation.
Where it works
Simple systems that are cooked once, eaten soon and not stressed: a sauce made and served, a bakery product where set and crumb matter more than storage. It is also the cheapest and the cleanest on a label, which is often the reason it is chosen.
Where it does not
The swollen granule is fragile. Shear from a pump or a homogeniser breaks it and the viscosity collapses. Acid hydrolyses it. Prolonged heat overcooks it. And retrogradation makes it a poor choice for anything chilled or frozen, where the result is weeping and a grainy texture.
What it interacts with
Sugar, which competes for water and delays gelatinisation. Acid, which destroys it. Hydrocolloids, which are often added precisely to protect it.
