gelatinisation

• gelatinisation helps to thicken foods that contain starch eg sauces, custards and gravies
• when starch granules are first mixed with liquid, they become suspended in it - if you dont stir the liquid these granules will sink to the bottom
• when the granules are heated with water , the bonds between the starch molecules start to break, allowing water molecules to eneter. as water is absorbed, the starch granules swell in size and soften
• between 62 degrees and 80 degrees, the starch granules burts open and release their starch into the liquid
• the release of starch causes the liquid to thicken. how thick the liquid becomes depends on the ratio of starch to liquid in the mixture - the higher the concentration of starch, the thicker the liquid
• when it cools, the liquid solidifies and a solid gel is formed, this is useful for making 'set' desserts like custards or lemon pie filling ~
• gelatinisation also happens when you cook starchy foods like pasta and rice - they swell, soften and release starch into the water as they cook