Gelatinization

The swelling of starch granules as they absorb water and are heated, which thickens sauces and fillings and sets baked goods.

Gelatinization: a saucepan of milk and cornstarch thickening into a smooth, glossy custard on a whisk, turning from thin to thick
  • Food science and baking chemistry

Also called: starch gelatinization

Raw starch granules do not dissolve in cold water. As they are heated in liquid, they absorb water, swell and release starch molecules, and the mixture thickens; this is how cornstarch and flour thicken pastry cream, pie fillings and puddings, and part of how cake and bread crumbs set. Different starches thicken at different temperatures and give different textures, from cloudy and firm to clear and glossy.

Sugar and acid slow or weaken thickening, and stirring too hard after thickening can thin a starch-set filling again. Over time, cooled starch gels can slowly firm up and weep, which is part of why bread goes stale.

Related entries

Sources

Written by VanillaGoods in our own words from these sources. Last reviewed October 15, 2026.

  1. Gelatinization and Solubility of Corn Starch during Heating in Excess Water: New Insights, Journal of Agricultural and Food Chemistry (Ratnayake & Jackson, 2006, 54(10):3712-3716), via University of Nebraska-Lincoln DigitalCommons
  2. DSC enthalpic transitions during starch gelatinization in excess water, dilute sodium chloride, and dilute sucrose solutions, Journal of the Science of Food and Agriculture (Ratnayake, Otani & Jackson, 2009, 89(12):2156-2164), via University of Nebraska-Lincoln DigitalCommons
  3. Using visible and near-infrared reflectance spectroscopy and differential scanning calorimetry to study starch, protein, and temperature effects on bread staling, USDA Agricultural Research Service (Xie, Dowell & Sun, Cereal Chemistry 81(2):249-254, 2004)