The best cornstarch substitutes depend on what you're thickening
Cornstarch thickens sauces, gravies, and pie fillings by absorbing liquid and turning it glossy. If you don't have cornstarch on hand, potato starch, arrowroot powder, and tapioca starch work almost identically—they thicken at the same temperature and create the same texture. For baking, flour is your most reliable swap, though it produces a slightly less transparent result. The substitute you choose depends on whether you're thickening a sauce, filling a pie, or mixing a cake batter.
Each replacement has a different thickening power. Some work at a 1-to-1 ratio with cornstarch; others require you to use more or less. Temperature matters too—some thickeners work in cold liquids, while others only set up when heated. Knowing these differences keeps your dish from turning out too thin, too thick, or with the wrong texture.
Key Takeaways
- Potato starch, arrowroot powder, and tapioca starch thicken at the same strength as cornstarch and can replace it in a 1-to-1 ratio in sauces and gravies.
- All-purpose flour thickens at half the strength of cornstarch, so you need twice as much, and it creates an opaque rather than glossy result.
- Arrowroot powder works in cold liquids and is the best choice for fruit pies and desserts that won't be reheated.
- Tapioca starch and potato starch break down if stirred too much or reheated, so use them for sauces you'll serve once.
- Xanthan gum thickens without heat and works in tiny amounts, making it ideal for gravies and cold sauces.
Potato starch for sauces and gravies
Potato starch is the closest match to cornstarch in both strength and behavior. Use it in a 1-to-1 ratio—if a recipe calls for 1 tablespoon of cornstarch, use 1 tablespoon of potato starch. Mix it with cold water first to make a slurry, then stir it into your hot sauce or gravy. It thickens at around 140°F (60°C), slightly lower than cornstarch, so your sauce will set faster.
The main drawback is texture after reheating. Potato starch breaks down if you reheat the sauce the next day or stir it too vigorously while it's cooking. If you're making a sauce to serve when ready, potato starch is ideal. If you need to store it and reheat it, arrowroot or tapioca starch hold up better.
Arrowroot powder for pies and desserts
Arrowroot powder thickens at a 1-to-1 ratio and creates a clear, glossy finish—the same look as cornstarch. It works in both hot and cold liquids, which makes it the best choice for fruit pies and custard-based desserts. Unlike potato starch, arrowroot doesn't break down when reheated, so a pie filling stays thick even after a day in the refrigerator.
Arrowroot does have one limitation: it thickens less effectively in acidic liquids like lemon juice or vinegar. If your pie filling or sauce contains a lot of acid, increase the arrowroot by 25 percent (use 1.25 tablespoons instead of 1 tablespoon). Arrowroot also doesn't work well in dairy-based sauces—the mixture can become slimy rather than smooth. For cream sauces, stick with cornstarch, potato starch, or flour.
Tapioca starch for Asian dishes and glazes
Tapioca starch (also called tapioca flour) thickens at a 1-to-1 ratio and produces a glossy, slightly slippery texture that's common in Asian cooking. It's the starch used in bubble tea and works well in stir-fry sauces, glazes, and sweet-and-sour dishes. Like potato starch, it breaks down if reheated or stirred too much, so use it for sauces you'll serve fresh.
Tapioca starch can create a slightly grainy texture if not mixed properly. Always make a slurry with cold water before adding it to hot liquid, and stir constantly for the first 30 seconds to prevent lumps. If you do end up with lumps, strain the sauce through a fine-mesh sieve.
All-purpose flour for baking and light thickening
Flour thickens at half the strength of cornstarch, so you need twice as much. If a recipe calls for 1 tablespoon of cornstarch, use 2 tablespoons of flour. Make a slurry with cold water or milk before adding it to hot liquid, just as you would with cornstarch. Flour works best in gravies, soups, and stews where a slightly opaque, matte finish is acceptable.
In baking, flour is a direct replacement at a 1-to-1 ratio because you're not relying on it to thicken—you're using it for structure. A cake or cookie recipe that calls for 1 tablespoon of cornstarch can use 1 tablespoon of flour instead. The texture will be slightly denser, but the result will still be edible. Flour doesn't create the same glossy finish as cornstarch in pie fillings, so if appearance matters, choose arrowroot or tapioca starch instead.
Xanthan gum for gravies and cold sauces
Xanthan gum is a thickener that works without heat and in tiny amounts—usually 1/4 teaspoon thickens 1 cup of liquid. It's useful for gravies that need to thicken quickly and for cold sauces like salad dressings or marinades. Xanthan gum doesn't require a slurry; you can sprinkle it directly into cold or hot liquid.
The catch is texture. Xanthan gum creates a slightly slimy, gel-like consistency that some people find unpleasant. It also clumps easily, so add it slowly while whisking constantly. Xanthan gum works best in small amounts and in dishes where a smooth, uniform texture is expected—gravies, salad dressings, and sauces rather than pie fillings.
Comparison table: thickening power and best uses
| Substitute | Ratio to cornstarch | Best for | Main limitation |
|---|---|---|---|
| Potato starch | 1-to-1 | Sauces, gravies (serve fresh) | Breaks down if reheated |
| Arrowroot powder | 1-to-1 | Pies, desserts, cold sauces | Doesn't work well in acidic or dairy liquids |
| Tapioca starch | 1-to-1 | Asian dishes, glazes (serve fresh) | Can become grainy; breaks down if reheated |
| All-purpose flour | 2-to-1 | Gravies, soups, baking | Creates opaque rather than glossy finish |
| Xanthan gum | 1/4 tsp per cup | Cold sauces, quick gravies | Can create slimy texture; clumps easily |
How to make a slurry so your sauce doesn't lump
A slurry is a mixture of starch and cold water that prevents lumps when you add it to hot liquid. Use a 1-to-1 ratio of starch to water—1 tablespoon of starch mixed with 1 tablespoon of cold water. Stir until smooth, with no visible lumps. The mixture should look like thin paste.
Pour the slurry slowly into your hot sauce or gravy while stirring constantly. Keep stirring for at least 30 seconds after you've added all the slurry. The sauce will thicken as it heats; if it's not thick enough after 1 minute of stirring, make another small slurry and repeat. Never add dry starch directly to hot liquid—it will clump and create a grainy texture that's hard to fix.
Frequently Asked Questions
Can I use rice flour instead of cornstarch?
Rice flour thickens at about half the strength of cornstarch, similar to all-purpose flour, so you'd need to use twice as much. It works in gravies and soups but creates a slightly grainy texture and opaque finish. For pie fillings and sauces where a clear, glossy look matters, arrowroot or tapioca starch are better choices.
What if I'm thickening a sauce with lemon juice or vinegar?
Acidic liquids weaken most starches. Arrowroot is the weakest in acid, so increase it by 25 percent. Potato starch and tapioca starch work better in acidic sauces than arrowroot does. Flour and xanthan gum are less affected by acid. If you're making a lemon sauce, potato starch or flour are your most reliable options.
Can I use when ready pudding mix to thicken a sauce?
when ready pudding mix contains starch plus sugar and flavorings, so it will thicken but also sweeten your sauce. It works only in dessert sauces where added sugar is acceptable. For savory gravies and sauces, use plain starch instead.
Why did my sauce break down when I reheated it?
Potato starch and tapioca starch break down over time and when reheated, becoming thin and watery. Arrowroot and flour hold up better to reheating. If you need a sauce that will be stored and reheated, use arrowroot powder or all-purpose flour instead of potato or tapioca starch.
How much xanthan gum do I need?
Start with 1/4 teaspoon per 1 cup of liquid and whisk it in slowly. Xanthan gum thickens quickly, so add it gradually and taste or check the texture as you go. Too much xanthan gum creates a slimy, unpleasant texture. If you overshoot, thin the sauce with a little more liquid rather than trying to add more thickener.