Cornstarch Substitute for Thickening: 8 Alternatives Compared

When a recipe for a sauce, gravy, or soup calls for cornstarch, it's usually to thicken the liquid to a desired consistency. But what if you don't have any cornstarch on hand? Or what if you're looking for a gluten-free or grain-free alternative? We in the test kitchen have experimented with a wide range of substitutes to see how they stack up. Here's what we found.

Quick Reference Guide to Cornstarch Substitutes

All-Purpose Flour

All-purpose flour is a common pantry staple, making it a convenient substitute for cornstarch. It contains starch, but also protein and fiber, which affect its thickening power and final texture.

How to Substitute

For every 1 tablespoon of cornstarch, you'll need to use 2 tablespoons of all-purpose flour. Flour has about half the thickening power of cornstarch, so you need to use more of it to achieve a similar result. It's also important to cook the flour for a few minutes to eliminate any raw, pasty taste.

When It Works

Flour works best in hearty, opaque sauces and gravies, like a classic country gravy or a beef stew. Because it creates a slightly cloudy appearance, it's not ideal for clear sauces or glazes. We found it integrated well into dairy-based sauces, creating a smooth, creamy texture.

When It Fails

We don't recommend using flour in delicate or clear sauces, as it can make them look muddy and dull. It also doesn't hold up well to freezing; sauces thickened with flour can become spongy and separate when thawed. Finally, because it contains gluten, it's not suitable for those with celiac disease or gluten sensitivity.

Taste and Texture

Sauces thickened with flour have a more matte appearance compared to the glossy sheen of cornstarch-thickened sauces. The texture is slightly less smooth, with a more rustic, hearty feel. If not cooked long enough, flour can impart a noticeable raw, pasty flavor.

Arrowroot Powder

Arrowroot powder, also known as arrowroot starch or arrowroot flour, is a starch extracted from the roots of the arrowroot plant. It's a popular gluten-free and grain-free thickener.

How to Substitute

Use arrowroot powder in a 1:1 ratio to cornstarch. For every 1 tablespoon of cornstarch, use 1 tablespoon of arrowroot powder. Like cornstarch, it's best to make a slurry with a small amount of cold liquid before adding it to a hot sauce to prevent clumping.

When It Works

Arrowroot powder creates a beautifully clear, glossy sauce, making it an excellent choice for fruit glazes and dessert sauces. It has a neutral flavor and holds up well to freezing and thawing, so it's a great option for dishes you plan to make ahead. We also found it works well with acidic ingredients, like citrus.

When It Fails

We discovered that arrowroot powder doesn't work well with dairy. When combined with milk or cream, it can create a slimy, unpleasant texture. It also tends to break down when overheated or cooked for a long time, so it's best to add it at the end of the cooking process.

Taste and Texture

Arrowroot powder has a neutral taste and creates a silky, smooth texture. The finished sauce is clear and glossy, very similar to what you'd get with cornstarch.

Tapioca Starch

Tapioca starch, also called tapioca flour, is extracted from the cassava root. It's another excellent gluten-free thickener.

How to Substitute

Substitute tapioca starch for cornstarch in a 1:1 ratio. Use a slurry to prevent clumping, just as you would with cornstarch.

When It Works

Tapioca starch is fantastic for creating a glossy, translucent sauce. It's particularly well-suited for pie fillings, as it can withstand prolonged baking times and doesn't get cloudy. It also freezes well, making it a good choice for make-ahead meals.

When It Fails

Tapioca starch can sometimes have a slightly sweet aftertaste, which might not be desirable in savory dishes. It can also become stringy if overcooked, so it's best to add it near the end of cooking. We also found it didn't perform as well in highly acidic sauces.

Taste and Texture

The texture of a tapioca-thickened sauce is very smooth and glossy. The flavor is mostly neutral, but as mentioned, a slight sweetness can sometimes be detected.

Potato Starch

Potato starch is a fine white powder made from the dried starch component of potatoes. It's a gluten-free thickener that behaves similarly to cornstarch in many ways.

How to Substitute

Use potato starch in a 1:1 ratio to cornstarch. A slurry is recommended to prevent lumps.

When It Works

Potato starch is an excellent all-purpose gluten-free thickener for soups, stews, and gravies. It has a neutral flavor and creates a clear, glossy sauce. It also thickens at a lower temperature than cornstarch, which can be useful in some applications.

When It Fails

Potato starch does not hold up well to boiling. If you boil a sauce thickened with potato starch, it will lose its thickening power and become thin again. For this reason, it's best to add it at the end of cooking and not let the sauce come to a rolling boil. It also doesn't freeze well, as it can cause the sauce to become spongy.

Taste and Texture

Potato starch has a neutral flavor and creates a smooth, silky texture. The sauce will be clear and glossy, similar to cornstarch.

Rice Flour

Rice flour is made from finely milled rice. It's a common ingredient in gluten-free baking and can also be used as a thickener.

How to Substitute

Use 2 tablespoons of rice flour for every 1 tablespoon of cornstarch. Like all-purpose flour, it has less thickening power than cornstarch.

When It Works

Rice flour is a good choice for delicate, light sauces where you want a subtle thickening effect. It's also a good option for making a roux as a base for gluten-free sauces. Because of its fine texture, it creates a very smooth finish.

When It Fails

We found that rice flour can sometimes have a slightly gritty texture if not cooked long enough. It also creates a more opaque sauce, so it's not ideal for clear glazes. Like all-purpose flour, it's not the best choice for sauces that will be frozen.

Taste and Texture

Rice flour has a very neutral flavor. The texture is smooth, but as noted, can be slightly gritty if undercooked. The final sauce will be opaque.

Xanthan Gum

Xanthan gum is a polysaccharide produced by the fermentation of sugar with a specific type of bacteria. It's a powerful thickener and stabilizer, and a little goes a long way.

How to Substitute

Use a very small amount of xanthan gum: 1/4 teaspoon for every 1 tablespoon of cornstarch. It's best to whisk it directly into the liquid, as it doesn't require heat to thicken.

When It Works

Xanthan gum is an excellent choice for gluten-free baking and for thickening salad dressings and other cold sauces. It's also very stable and can be used in a wide range of temperatures and pH levels. Because you need so little, it doesn't add any noticeable flavor or color to the final dish.

When It Fails

If you use too much xanthan gum, the texture can become unpleasantly slimy or gummy. It's very important to measure it carefully. We also found that it can be tricky to disperse evenly, sometimes leading to small, gelatinous clumps.

Taste and Texture

Xanthan gum is flavorless. When used correctly, it creates a smooth, stable texture. However, overuse can result in a slimy, synthetic mouthfeel.

Ground Flaxseed

Ground flaxseed, when mixed with water, forms a gel-like substance that can be used as a thickener and binder.

How to Substitute

For every 1 tablespoon of cornstarch, mix 1 tablespoon of ground flaxseed with 4 tablespoons of water. Let it sit for a few minutes to form a gel, then add it to your sauce.

When It Works

Ground flaxseed is a good option for hearty, rustic dishes where a slightly nutty flavor and coarser texture are acceptable. It's a great way to add extra fiber and omega-3 fatty acids to your cooking. We found it worked well in things like lentil soup or a hearty beef stew.

When It Fails

Ground flaxseed is not a good choice for delicate or clear sauces. It will make the sauce opaque and will impart a noticeable nutty flavor and a slightly gritty texture. It's also not a powerful thickener, so it's best for dishes that only need a little bit of body.

Taste and Texture

Ground flaxseed has a distinct nutty flavor and a somewhat gritty texture. The final sauce will be opaque and will have a more rustic, less refined consistency.

Reduction

Sometimes, the best way to thicken a sauce is to not add a thickener at all. The reduction method involves simply simmering a liquid until some of the water evaporates, concentrating the flavors and naturally thickening the sauce.

How to Substitute

There's no direct ratio for this method. Simply let your sauce simmer over low to medium heat until it has reached your desired consistency. This can take anywhere from a few minutes to an hour, depending on the sauce and how much you want to reduce it.

When It Works

Reduction is an excellent technique for concentrating the flavors of a sauce, particularly pan sauces, tomato sauces, and wine-based sauces. It's a great way to avoid adding extra starch to a dish and to let the natural flavors of the ingredients shine.

When It Fails

This method doesn't work when you need to thicken a large volume of liquid quickly, or when you don't want the flavors to become too concentrated. It also won't work for dishes where a certain amount of liquid is essential, like a soup that needs to serve a specific number of people.

Taste and Texture

The reduction method results in a sauce with a very intense, concentrated flavor. The texture will be naturally thick, but not in the same starchy way as a sauce thickened with cornstarch. The final consistency will depend on how much you reduce the liquid.

Practical Tips and Common Mistakes to Avoid

• Always make a slurry: For most starch-based thickeners, mixing them with a small amount of cold liquid before adding them to a hot sauce is crucial to prevent clumping.
• Cook it out: When using flour, be sure to cook the sauce for a few minutes to eliminate any raw, pasty taste.
• Don't boil potato starch: Boiling a sauce thickened with potato starch will cause it to break down and become thin again.
• Be careful with xanthan gum: A little goes a long way. Measure carefully to avoid a slimy texture.
• Consider the final appearance: For clear, glossy sauces, choose arrowroot, tapioca, or potato starch. For opaque, hearty sauces, flour or rice flour are better choices.
• Think about flavor: Most thickeners are neutral, but some, like ground flaxseed, will add their own flavor to the dish.

Frequently Asked Questions

1. Can I use whole wheat flour instead of all-purpose flour?

Yes, but it will impart a more noticeable flavor and a darker color to your sauce. It also has slightly less thickening power, so you may need to use a little more.

2. What's the best gluten-free substitute for cornstarch?

Arrowroot powder, tapioca starch, and potato starch are all excellent gluten-free substitutes that behave similarly to cornstarch. The best choice depends on the specific application, as discussed above.

3. Can I make my own potato starch?

While it's possible to make your own potato starch by grating potatoes, mixing them with water, and then collecting the starch that settles at the bottom, it's a labor-intensive process. Commercially available potato starch is a more convenient option.

4. Why did my arrowroot-thickened sauce get slimy?

This is a common problem when arrowroot powder is combined with dairy. The two don't play well together, so it's best to choose a different thickener for cream-based sauces.

5. Can I use corn flour instead of cornstarch?

Corn flour and cornstarch are not the same thing. Corn flour is made from finely ground, dried corn, while cornstarch is made from the starchy part of the corn kernel. Corn flour has less thickening power than cornstarch and will impart a corn flavor to your dish. In most cases, it's not a good substitute.