How to Use Flour or Cornstarch to Thicken Sauce, Gravy, and Soup (2024)

FAQs

How to Use Flour or Cornstarch to Thicken Sauce, Gravy, and Soup? ›

Use two tablespoons flour mixed with ¼ cup cold water for each cup of medium-thick sauce. Thoroughly mix in the water to prevent lumps. After stirring the combined flour and water into the sauce, cook and stir over medium heat until thickened and bubbly.

If your gravy is on the skimpy side, you can thicken it quickly with flour or cornstarch. But don't add your thickener directly to the gravy, which will create lumps. Instead, try stirring in three or four tablespoons of flour or cornstarch into a small amount of cold water until you have a smooth paste.

Both are cereal starches, but cornstarch is pure starch while flour contains gluten. The gluten reduces the thickening power of flour. One tablespoon of cornstarch thickens one cup (250 mL) of liquid to a medium consistency. It takes two tablespoons of flour—twice as much—to thicken the same amount of liquid.

Start by combining one tablespoon of cornstarch with two tablespoons of cold water in a small bowl and stirring the mixture until it forms a thick paste with no lumps. Next, slowly add the cornstarch slurry to the simmering soup, stirring continuously as you go.

To make a good cheese sauce or gravy, you need a thickening agent. Cornstarch and flour are two common thickening agents in the home kitchen. Both are cereal starches and when they're mixed with a liquid and then heated, they gelatinize.

Make a Slurry

If you want to use flour, mix 2 tablespoons of flour per 1 cup of cool liquid. Whisk the slurry until it is smooth and lump-free, then add about 1 tablespoon at a time to your hot pan drippings and liquid mixture, using a whisk to thoroughly combine.

Cornstarch is a common thickening agent in the culinary arts, but if you add it directly to the liquid you want to thicken, it will clump up. To thicken a sauce or soup with cornstarch, you first need to make a slurry, which is a mixture of equal parts cornstarch and liquid (usually water, stock or wine).

Cornstarch needs heat (in the ballpark of 203°F) in order for “starch gelatinization”—that is, the scientific process in which starch granules swell and absorb water—to occur. In other words, if you don't heat your cornstarch to a high enough temperature, your mixture will never thicken.

Cornstarch has twice the thickening power of flour. When a gravy, sauce, soup or stew recipe calls for flour, use half as much cornstarch to thicken. To thicken hot liquids, first mix cornstarch with a little cold water until smooth. Gradually stir into hot liquid until blended.

How much cornstarch to thicken 4 cups of soup? ›

If you're cooking hot liquids like sauces, stock or broth, 1 tablespoon of corn starch per cup of liquid will give you a thin to medium consistency that's appropriate for soups or very thin sauces. 2 tablespoons per cup will give you a thicker, more gravy-like consistency.

Add Flour Or Cornstarch

You can thicken soup by adding flour, cornstarch, or another starchy substitute. For the best results, never add flour or cornstarch directly to your soup. If you do, it will clump up on top. Instead, ladle a small amount of broth into a separate bowl and let it cool.

Add flour or cornflour

Put a tablespoon of either into a small bowl and stir in 2-3 tbsp of the soup until you have a smooth mixture. Stir this back into the soup and bring it to a simmer. Cook for a few minutes to allow the starch granules to burst to thicken, and to cook out any flour flavour.

Browning adds more flavor to the gravy and gets rid of the raw flour taste. You're basically making a roux. We find that a flour-based gravy holds up better and reheats better later, which is why we tend to prefer using flour over cornstarch to make gravy unless we have a guest who is eating gluten-free.

Cornstarch. Cornstarch is a very effective thickener, and a little bit can go a long way. Add cornstarch to a small amount of cold water or other liquid (wine or stock) and whisk into a thick slurry. Then the slurry can be stirred into a simmering soup, a bit at a time to set the final consistency.

Cornstarch has twice the thickening power of all-purpose flour, which means you'll want to use twice as much: For every 1 tablespoon of cornstarch, you'll want to use 2 tablespoons of flour.

All-Purpose Flour

It also won't provide the same thin, shatteringly crisp crust cornstarch gives to some fried foods, but it can work for either situation in a pinch. Some tips: Use two tablespoons of flour for every tablespoon of cornstarch.

To make a slurry, start with 1 to 2 ratio of cornstarch to water. For example, prepare 1 tablespoon of cornstarch and 2 tablespoons of water. Then whisk together really well. When you add more water, it just takes more time to thicken the sauce or soup.

If your sauce is really that watery, cornstarch is a safer bet, but technically, baking powder will work, too.