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? ›

For each cup of liquid, you want to thicken, start with 1 tablespoon of cornstarch in a small bowl. Add an equal amount of cold liquid and stir until smooth paste forms. This is your slurry. Whisk the slurry into the hot, simmering liquid that you want to thicken.

It's important to note that cornstarch has twice the thickening power of flour.

Cornstarch, or corn flour, can be used to thicken soup through its high starch content. Cornstarch is a great thickener for soup because only a little bit is needed to significantly thicken a soup, and it will not affect the flavor profile of the soup.

Cornstarch is finer, silkier, and doesn't have the protein of flour. It needs to be mixed completely with cold water before being added to boiling liquid, and once added, it needs to be cooked only until the liquid has thickened. If you cook it too long, it will break down and the liquid will lose its thickness.

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.

Using flour as a thickener will make the sauce opaque and cloudy while cornstarch leaves a shiny, more translucent finish. This is a desirable feature for fruit pie fillings and certain sauces, especially in Chinese stir-fries. If a sauce is quite acidic, cornstarch won't thicken it quite as well.

Cornstarch is one of the most commonly used thickeners, but it has some unique traits. So thanks for the good question! Cornstarch must be cooked to 95°C (203°F) before thickening begins. At that point, it usually thickens fairly quickly and the sauce turns from opaque to transparent.

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.

The most classic and surefire way to thicken a broth-based soup is with a cornstarch slurry. Whisk together equal parts cornstarch (or arrowroot) and water or broth, then whisk it into the pot of soup. A good ratio to get to a pleasant thickness without your soup tasting goopy or heavy is one tablespoon.

It's important that the soup is hot as this will help to dissolve the flour. Carefully dunk a heat-safe cup into the soup pot and transfer it into a small bowl.

What happens if you add too much cornstarch? ›

Plus, using too much cornstarch can result in an excessively brittle coating, which might be undesirable for a particular dish. Like any pantry ingredient, cornstarch is just another tool in the toolbox we call our kitchen.

This means it's possible to swap your cornstarch for flour, but you will need more of it to get the same effect. In general, it's recommended that you use twice as much white flour as cornstarch for thickening purposes. So if you need 1 tablespoon of cornstarch, use 2 tablespoons of white flour.

Carbohydrates like potato starch are natural thickening agents, so try to use a particularly starchy potato, like a russet potato or a Yukon Gold potato, and make sure to use raw potatoes rather than already cooked potatoes.

Flour can be mixed with a little cold water to make what is unattractively called a 'slurry', which is then stirred to disperse it and stop it forming clumps – a technique called 'slaking'. After adding to the stew, it's brought to the boil to cook out the flour taste and allow the starch to swell.

First, you can create a slurry by whisking 2 tablespoons of flour with cold water and adding it gradually to the soup. Another method of using flour to thicken soup is by making a roux on the stovetop. A roux, which is a mixture of fat and flour, is often used as a base for sauces and is an easy way to add starch.

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.

Arrowroot

Some people prefer arrowroot to cornstarch because it contains more fiber (1, 2). It also forms a clear gel when mixed with water, so it's great for thickening clear liquids ( 3 ). It's recommended to use twice as much arrowroot as cornstarch to get similar results.

Roux is commonly made with flour, but you can also sub in cornstarch or arrowroot powder. Mix the cornstarch or arrowroot powder with water to form a slurry before adding it to the pan and cooking it with the fat.

Given that baking powder only works as a thickener because of the cornstarch in it, it makes more sense to just use plain cornstarch. This way you'll have better control over the consistency without worrying about the other ingredients in the baking powder that could make your sauce taste bitter.