Here’s how to make a cornstarch slurry! Use this mixture to thicken sauces, soups, stews and more to a glossy consistency.
Want to thicken a sauce or stew? Cornstarch is the answer. That fine white powder is the ultimate culinary shape shifter. It gives watery sauces a luxuriously glossy sheen, and it gives tofu and chicken an ultra-crisp exterior.
But before start: you can’t simply sprinkle a bit of the white powder into your dish on its own. You’ll need this special step: a cornstarch slurry! As two cookbook authors, this is one of our top tips for working with this ingredient.
What’s A Cornstarch Slurry?
A cornstarch slurry is a mix of cornstarch and water (or another room temperature liquid). If dry cornstarch is added directly to a dish, it clumps up. The ratio of cornstarch to water is typically equal parts cornstarch and liquid.
Cornstarch must be heated to around 203°F for the thickening to occur. This is the temperature where “starch gelatinization” happens: the process where the the particles of cornstarch absorb water. So in order to be activated, the cornstarch slurry should be heated once it’s added to the dish.
When to make a cornstarch slurry? Use it to thicken stir fry sauces, soups, stews, gravies, fruit sauces, compotes, and other sauces where you want a thick, glossy body.
How To Make A Cornstarch Slurry
Here are the basic steps to a cornstarch slurry (or jump to the recipe below):
- Mix 1 tablespoon cornstarch with 1 ½ tablespoons water. This amount of cornstarch should create a moderate amount of thickening, but this depends upon the quantity of liquid and exactly what you’re making. Start with 1 tablespoon, then add more as necessary depending on your recipe.
- Pour the slurry into the heated dish (sauce, soup, stew, etc). You can also start with it cold and heat it along with the full recipe.
- Stir constantly as it thickens. Cornstarch can still clump up if you don’t stir. Continue to stir as the sauce thickens. If it’s not thick enough, add another ½ or 1 tablespoon mixed cornstarch slurry and continue to stir.
The Slurry Ratio (How Much to Use)
My go-to ratio is 1 tablespoon cornstarch to 1 ½ tablespoons water. How much you need depends on how much liquid you’re thickening. Here’s a basic starting point:
| Amount of liquid to thicken | Light body (for soups, stews) | Medium body (for sauces, gravy) |
|---|---|---|
| 1 cup | 1 ½ teaspoons cornstarch | 1 tablespoon cornstarch |
| 2 cups | 1 tablespoon | 2 tablespoons |
| 3 cups | 1 ½ tablespoons | 3 tablespoons |
| 4 cups | 2 tablespoons | ¼ cup |
| 8 cups | ¼ cup | ½ cup |
When to Add a Cornstarch Slurry
The cornstarch slurry should thicken a liquid within about 1 minute of applying heat. Here’s when to add it for different types of recipes:
- Stir fries: For a stir fry, add it in the last minute of cooking, or whisk it right your stir fry sauce.
- Soups and chili: Stir it in during the last 5 minutes, once the vegetables are cooked through.
- Gravy: Whisk it into the simmering liquid and cook for 1 minute.
- Slow cooker (crock pot): Stir it in for the last 30 minutes and switch to High.
- Fruit sauces and pie fillings: Add it to the fruit sauce while simmering and cook until it looks shiny; this should be about 1 to 2 minutes.
Cornstarch Substitutes
Don’t want to use cornstarch? A great substitute is arrowroot starch, aka arrowroot powder. It’s the starch extracted from the arrowroot plant, and often used in gluten-free baking to bring a light texture to baked goods. It’s a great substitute for cornstarch that works for people with corn allergies, and it provides that nice glossy shine just like cornstarch. Replace arrowroot starch 1 for 1 with cornstarch.
You can also make an all-purpose flour slurry in the same way as a cornstarch slurry. However, flour doesn’t thicken in the same way: it’s not as powerful of a thickener and the sauce doesn’t get as glossy. I recommend using it in soups and gravies.
Recipes That Use A Cornstarch Slurry
Here are a few recipes that use the concept of a cornstarch slurry:
- Stir fries like Shrimp Stir Fry, Cauliflower Stir Fry, Tofu Stir Fry or Baby Bok Choy Stir Fry
- Fruit sauces like Blueberry Sauce, Blueberry Compote, Strawberry Compote or Strawberry Sauce
- Sauces like Balsamic Glaze, Taco Sauce or Teriyaki Sauce
- Pie fillings like Strawberry Pie
Dietary Notes
This cornstarch slurry is vegetarian, vegan, plant-based, dairy-free and gluten-free.
Frequently Asked Questions
Adding cornstarch directly to a hot liquid will cause it to clump up. Creating a slurry allows the cornstarch to dissolve evenly, preventing lumps and ensuring a smooth, thickened consistency.
Whisk the slurry thoroughly before adding it to the hot liquid. Gradually pour it in while stirring continuously to prevent clumping. Bring the mixture to a simmer for about a minute to fully activate the cornstarch and achieve the desired thickness.
Yes, you can use other liquids like broth, milk, or even juice to make a slurry. Just keep in mind that the flavor of the liquid will be incorporated into your dish.
How to Make a Cornstarch Slurry
Here’s how to make a cornstarch slurry! Use this mixture to thicken sauces, soups, stews and more to a glossy consistency.
- Prep Time: 2 minutes
- Cook Time: 0 minutes
- Total Time: 2 minutes
- Yield: N/A
- Category: Sauce
- Method: Stirred
- Cuisine: N/A
- Diet: Vegan
Ingredients
- 1 tablespoon cornstarch
- 1 ½ tablespoons water (or stock)
Instructions
- Whisk together the cornstarch and water in a small bowl until fully combined.
- Pour the mixture into the hot liquid you plan to thicken: stir fry sauce, soup, stew, fruit compote or sauce, etc. Stir constantly and the sauce should thicken in about 30 seconds to 1 minute. If it’s not thick enough, repeat with another tablespoon of cornstarch dissolved in water.
I need to know how to make the black cherry syrup thick to put in my vanilla pound cake creating a marbleized effect like a swirl. I put dollops of the cherry mixture and slightly swirled it. The swirl effect was present but I want a stronger taste of the black cherry syrup. Thank you
I’m not sure, sorry!
I want to make a vanilla pound cake with black cherry syrup making a labeled cake.
this could definetly be helpful for someone one day