cornstarch dissolved in 2 tbsp. water

Cornstarch, also known as corn flour or maize starch, is a fine white powder derived from the endosperm of corn (maize) kernels through wet milling and extraction. The starch granules are isolated, dried, and pulverized into an impalpable powder that remains insoluble in cold water but gelatinizes when heated, creating a glossy, translucent thickening agent. Cornstarch is nearly pure carbohydrate with minimal flavor, making it a neutral thickening medium in both sweet and savory preparations.

When cornstarch is dissolved in cold water or other liquid, it forms a slurry or suspension known as a "cornstarch slurry" or "slurry thickener." This technique—mixing cornstarch with a small amount of cold liquid before adding to a hot preparation—prevents clumping and ensures even distribution of the starch granules, which then gelatinize uniformly when exposed to heat, producing a smooth, lump-free thickened sauce or filling.

A cornstarch slurry is essential in both classical European and Asian cuisines as a reliable thickening agent for sauces, gravies, custards, fillings, and stir-fry liquids. In Asian cooking, it is particularly valued for achieving the silky, glossy consistency characteristic of Cantonese and Chinese cuisine. The slurry method—dispersing cornstarch in cold liquid before adding to a simmering dish—prevents lumping and ensures a smooth texture. It is used to thicken fruit pies, puddings, and glazes, and provides body to gravies without the richness of flour-based roux. Cornstarch produces a more translucent thickening than flour, making it preferred in dishes where clarity of the sauce is important, such as fruit sauces and delicate stocks.