Cornstarch and Water Slurry

Introduction

A cornstarch slurry is a quick thickener made with 1 tablespoon cornstarch and 2 tablespoons cold water. You use it when a sauce, soup, or stir-fry needs body without adding flour or a long simmer. It takes about 2 minutes and works best when you re-mix it right before pouring it in.

Recipe Details

• Prep Time: 2 minutes
• Cook Time: 0 minutes
• Total Time: 2 minutes
• Servings: 1 batch

Ingredients

• 1 tablespoon cornstarch
• 2 tablespoons cold water

Instructions

1. Pour the cornstarch in a cup.
2. Add water and mix thoroughly with a fork. Re-mix as needed to keep the cornstarch in suspension.

Variations

• Replace the cornstarch with arrowroot powder in the same amount if you want a clearer, glossier finish in sauces.
• Replace the cornstarch with tapioca starch in the same amount for a slightly silkier texture that works well in fruit fillings and glossy gravies.
• Increase the cold water to 3 tablespoons if you want a thinner slurry that is easier to pour into a very small saucepan without clumping.
• Double both the cornstarch and cold water if you are thickening a larger volume of liquid; the texture stays the same, but you get more thickening power in one mix.

Tips for Success

• Use cold water, not warm or hot, so the cornstarch disperses smoothly instead of forming lumps.
• Mix in a cup with enough room for a fork so you can break up any dry pockets at the bottom.
• Re-mix right before using because cornstarch settles fast and the thickening power won’t be evenly distributed if it sits.
• Add the slurry to a hot liquid gradually while stirring so it thickens evenly instead of creating gelled streaks.
• Stop adding once the liquid looks slightly thinner than you want; cornstarch thickens fully after a brief simmer.

Storage and Reheating

Store the slurry in a small sealed jar or airtight container in the fridge for up to 1 day. It will separate as it sits, so shake or stir it thoroughly before using.

FAQ

Can you use warm water instead of cold water?

No. Warm water starts hydrating the cornstarch too quickly and makes lumps much more likely.

How much liquid will this thicken?

This batch is usually enough to lightly thicken about 1 to 2 cups of hot liquid, depending on how thick you want the final sauce or soup.

Can you make it ahead?

Yes, but only briefly. Keep it in the fridge for up to 1 day and stir or shake it well before using because the cornstarch settles to the bottom.

Can you swap cornstarch for another starch?

Yes. Arrowroot powder or tapioca starch can be used in the same amount, though the final texture and gloss will be a little different.