How to Make a Cornstarch Slurry

This is how cornstarch is prepared! Use this mixture to thicken sauces, soups, stews and more to a glossy consistency.

Would you like to thicken a sauce or stew? Cornstarch is the answer. This fine white powder is the ultimate culinary shapeshifter. It adds a luxurious, glossy sheen to watery sauces and gives tofu and chicken an ultra-crunchy finish. But before you start, remember that you can’t just sprinkle a little white powder on your dish. You need this specific step: a cornstarch.

What is cornstarch?

A cornstarch mash is a mixture of cornstarch and water (or other liquid at room temperature). When dry cornstarch is added directly to a dish, it clumps together. The ratio of cornstarch to water is usually equal parts cornstarch and liquid.

Cornstarch needs to be heated to about 203°F for thickening to occur. This is the temperature at which “starch gelatinization” occurs: the process by which cornstarch particles absorb water. Therefore, in order to become activated, the cornstarch slurry must be heated once it has been added to the bowl.

When do you make cornstarch? Use it to thicken pan sauces, soups, stews, gravies, fruit sauces, compotes and other sauces where you want a thick, glossy body.

How to Make Cornstarch: Basic Steps

Ready to thicken your sauce? Here are the basic steps for a cornstarch porridge (or continue with the recipe below):

• Mix 1 tablespoon of cornstarch with 1 ½ tablespoons of water. This amount of cornstarch should produce a moderate amount of thickening, but it depends on how much liquid and what you’re making. Start with 1 tbsp, then add more as needed according to your recipe.
• Pour the porridge into the heated dish (sauce, soup, stew, etc.). You can also start cold and heat up with the full recipe.
• Stir constantly while thickening. Cornstarch can still clump together if you don’t stir. Keep stirring while the sauce thickens. If it’s not thick enough, add another ½ or 1 tablespoon of the mixed cornstarch slurry and keep stirring.

Alternative to cornstarch: arrowroot

Don’t want to use cornstarch? A great substitute is arrowroot starch, also known as arrowroot powder. It’s the starch derived from arrowroot and is commonly used in gluten-free baking to add light texture to baked goods. It’s a great cornstarch substitute suitable for those with corn allergies and it offers that nice glossy shine just like cornstarch. Replace arrowroot starch 1:1 with cornstarch.

You can also make porridge the same way as cornstarch. However, flour doesn’t thicken in the same way: it’s not as powerful a thickener, and the sauce isn’t as glossy. We therefore recommend arrowroot starch as the best substitute.

Recipes with cornstarch

Want concrete examples? Here are some recipes that use the concept of cornstarch:

This cornstarch is…

Vegetarian, vegan, plant-based, dairy-free and gluten-free.