Cornstarch
A fine, chalky starch powder milled from corn endosperm, used as a powerful thickening agent and tenderizer.
1 Tbsp Cornstarch = 8g • Thickening ratio: 1 Tbsp cornstarch thickens 1 cup of liquid
Cornstarch is a pure carbohydrate starch extracted from the endosperm of the corn kernel (maize). It is a fine, bright white powder that squeaks when pinched. In cooking, it is used as a powerful thickening agent for sauces, gravies, custards, pie fillings, and puddings. When heated with liquid, the starch granules absorb water and swell, a process called gelatinization. This occurs at around 144°F to 162°F (62°C to 72°C), turning cloudy liquids clear and thick. Cornstarch has twice the thickening power of wheat flour and yields a glossy finish rather than a matte one.
In baking, cornstarch is blended with wheat flour to tenderize the crumb. By diluting the protein content of all-purpose flour, it limits gluten development, mimicking the soft properties of cake flour. It is also added to cookie doughs to prevent spreading and create a soft, melt-in-your-mouth texture. To thick hot liquids, cornstarch must first be dissolved in a cold liquid slurry to prevent clumping.
Adding dry cornstarch directly to hot liquids. The starch instantly gelatinizes upon contact with heat, forming dry, lumpy clumps that cannot be whisked out. Always mix into a cold liquid slurry first.
In the UK and Australia, cornstarch is commonly labeled as Cornflour. This is identical to US cornstarch, not to be confused with yellow corn meal.
Use to thicken fruit pie fillings, puddings, custards, stir-fry sauces, or to soften flour in cakes and shortbread cookies.
Replace 1 tablespoon cornstarch with 2 tablespoons all-purpose flour (requires boiling longer) or 1 tablespoon arrowroot powder.
Keep in an airtight container in a cool, dry place indefinitely. Starch is highly sensitive to moisture and will clump if exposed to humidity.
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