Cornflour (Cornstarch)

Food · Pantry & Condiment · Food, Typed Supps

Pure starch, nothing else — which is exactly what it is for.

Stage by stage

No flavour (Taste): Pure starch contributes texture and nothing else, which is the point of it.
Gelatinisation (The pan): Granules swell and burst near 90 °C, trapping water into a gel.
Rapid starch (Small intestine): No fibre or protein to slow it, though the quantities used are usually small.
Wheat risk (Gut): Australian "cornflour" may be wheat starch — the ingredient list is the only check.

Timing

Nothing to time nutritionally. Technically, cold slurry first, and do not boil hard once it has thickened.

Time to effect

~90 °C: Where the starch gelatinises and the sauce thickens.
15–30 min: Glycaemic response, at intakes large enough to matter.

Allergens

None of the fourteen major allergens. Derived from what this food is, not from a product label.

Eating patterns

Fits: Vegan, Vegetarian, Pescatarian, Halal, Kosher, Gluten-free. Depends on the product: Low-FODMAP.

Satiety

Not scored: the satiety index is measured on 240 kcal servings, and nobody eats a 240 kcal serving of this. The question does not apply rather than the answer being unknown.

Environmental footprint

1.7 kg CO2e and 216 litres of freshwater per kg, matched to "Maize" in Poore & Nemecek (2018), Science 360.

Cost band

Cheap — roughly £1.5 per kg, as a band midpoint rather than a price.

Key nutrients

Carbohydrate

Nutrition per 100g

Calories: 348
Protein: 0.4g
Carbohydrate: 84.1g
Fat: 0.6g
of which saturated: 0.1g
Sodium: 16mg

Food vs. supplement

Cornflour is one of the few foods whose entire purpose is physical rather than nutritional. It is in the dish to change how it behaves, and its nutrition panel is beside the point.

Kitchen tip

Slurry it in cold water before it goes anywhere near the pan. Dry cornflour hitting hot liquid clumps on contact and never recovers.

Common myth

“Cornflour is corn, so it’s gluten-free.” In reality: Not necessarily in Australia, where "cornflour" can legally describe a product made from wheat starch. AFCD lists the two separately for that reason. For coeliac disease the maize-only version is the one to buy, and the only reliable way to tell them apart is the ingredient list — the front of the packet often looks identical.