What does cornstarch mean?
Cornstarch is a fine, powdery white substance made by grinding the starchy endosperm of corn kernels. Prized for being nearly flavorless and producing a clear, glossy gel, it is the go-to thickening agent in American kitchens, where it gives body to gravies, sauces, puddings, and pie fillings. A small amount dissolved in cold water — a mixture cooks call a slurry — is stirred into hot liquids near the end of cooking, where it thickens quickly at relatively low temperatures. Beyond the kitchen, cornstarch serves industrial purposes, appearing in papermaking, adhesives, cosmetics, and even biodegradable plastics, while a playful mix of cornstarch and water creates oobleck, the famous non-Newtonian fluid that behaves as both liquid and solid. Known as 'cornflour' in Britain and much of the English-speaking world outside North America, cornstarch should not be confused with cornmeal or corn flour, which are ground from the whole kernel and carry a distinct corn taste. It is a humble pantry staple whose quiet versatility makes it one of the most useful ingredients in modern cooking.
nounA fine, white powder made from the endosperm of corn kernels, used chiefly as a thickening agent in cooking and baking.
- A fine white powder made from corn endosperm, used as a thickener in cooking and baking.
- (Figuratively, rare) Something that stiffens or thickens a mixture or situation.
"Whisk a tablespoon of cornstarch into the cold milk before heating it to prevent lumps."
"Dust the fruit with cornstarch before filling the pie so the juices set as it bakes."
"The sauce was too thin, so she whisked in a slurry of cornstarch and water."
Rarely pluralized since cornstarch is normally a mass noun; the plural appears only when distinguishing types, grades, or brands of the product.
"The test kitchen compared several cornstarches to see which produced the glossiest glaze."
Mix cornstarch with water and you get oobleck — a substance that's liquid when stirred but solid when punched, beloved by science teachers everywhere.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cornstarch
Cornstarch is a transparent compound of 'corn' and 'starch', both ancient Germanic words. 'Corn' comes from Old English 'corn', meaning grain or seed, cognate with Dutch 'koren' and German 'Korn', while 'starch' derives from Middle English 'sterchen', to stiffen, ultimately rooted in the Old English adjective 'stearc', meaning stiff or strong — the same source that gives us the word 'stark'. The compound arose once corn became the dominant cereal crop in North America, where refining the kernel's endosperm into pure starch became a commercial process in the nineteenth century. Its British counterpart, 'cornflour', follows the same logic using the British sense of 'corn' for any cereal grain.
How cornstarch is actually used
Primarily an uncountable noun in culinary contexts ('add cornstarch'), though 'cornstarchs' occasionally appears when referring to varieties or brands. It is the standard American term; speakers of British English almost always say 'cornflour'. Unlike flour, cornstarch is typically mixed with cold water before being added to hot liquids to avoid clumping.
Easily confused with cornstarch
In most of the world, 'cornflour' is simply the British and international name for the same product Americans call 'cornstarch', though in the US 'corn flour' can also refer to a finely ground whole-corn meal.
Cornmeal is coarsely ground whole dried corn with a gritty texture and corn flavor, whereas cornstarch is a refined white powder extracted purely for its thickening starch.