How To Thicken Sauce (What To Use & Why)

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You are standing over the stove, inhaling the delicious aromas of your latest home-cooked 5-star sauce, but something just doesn’t seem right. The flavors are there and you followed the recipe perfectly, but it simply doesn’t have the hearty thickness you are after. That soulful smooth texture that you expect from such a spectacular sauce. Instead, you are left with a runny, lackluster liquid that will not impress your guests like you had hoped it would.

Not to worry, I am here to help you out with some quick and easy methods on how to thicken sauce so that it can truly shine on your dish. So let’s grab our saucepans and dive right in!

How To Thicken Sauce

The most common method for thickening a sauce is to reduce it. Reducing a sauce is the act of heating it to evaporate some of the moisture. The other main way to thicken various sauces is to add a thickener. Some common thickeners are flour, cornstarch, xantham gum, egg yolk, and tomato paste. You can also simply add more of your other ingredients in some cases.

What are the thickening agents for sauces?

The first thing we must address is what exactly are thickening agents? I can’t just tell you to throw something in your food without telling you why or what they do! To learn how to thicken sauce properly, we must first answer what the various thickening options available are and how they work.

Thickening agents are different ingredients used in cooking to make a liquid more dense and viscous. Throughout history, people have developed various strategies for making sauces, stews, and soups thicker, heartier, and ultimately, more delicious!

Some people might use flour in a roux, while others might use tomato paste for their tomato-based sauces. There are countless options available, and what you choose should depend on the flavors you hope to enhance in your dish.

This article will touch on the best way to thicken your sauce, no matter what it is. Whether you have flour, cornstarch, arrowroot, xanthan gum, eggs, tomato paste, or none of the above at your disposal, I will break down the steps to getting your sauce to the gloriously thick liquid you envisioned it to be.

How do You Thicken White Sauce?

A white sauce is almost always made from a roux. To thicken a standard white sauce, you will be using flour.

The method you are probably most familiar with for how to thicken the sauce is flour. Around since the 17th century, the roux has been the gold standard for sauce. In the French school of cooking, a roux is one of the first things you learn to make, and you never stop making it.

A roux is simply flour and butter combined together over heat until golden brown and can be used to make your sauces and soups less runny. It is not itself a sauce, but it is the basis of many sauces.

How do you thicken sauce with flour?

To thicken sauce with flour, you will want to make a roux. To begin creating your roux, melt butter in a saucepan over medium or low heat and slowly whisk in all-purpose flour. Continue adding flour until you have a mixture of equal parts butter and flour. Continue whisking the sauce until it is smooth and then let simmer at medium heat until it is a light golden brown color, typically takes about 1 minute. Then, you can take your delicious roux and slowly add it to your sauce or soup to thicken it.

Can You Use Flour Without Butter?

Alternatively, if you want to avoid the extra calories from using butter, you can also combine 1 Tablespoon of flour with 1/8th cup of cold water. Whisking these together will give you an excellent thickening agent for your sauce. Introduce it slowly by stirring well and continue adding flour this way until you reach your desired consistency.

As long as you are not concerned with keeping the dish gluten-free and don’t mind the sauce having a slightly cloudy appearance, a roux is a way to go. If, however, you want to keep the sauce gluten-free, then I recommend trying one of the other methods below.

Can you Make A Roux With Cornstarch?

A roux is traditionally made with butter and flour. While you can use cornstarch to thicken the sauce similarly to a roux, you should not replace a roux in a recipe unless you specifically need to make it gluten-free, as this will change the entire taste of the dish.

How to thicken sauce without flour

If you don’t have flour available or you wish to make a gluten-free meal, there are a few other options. Here are a few ingredients you can try in your recipes.


Cornstarch is a type of carb derived from corn and can be used in much the same way as flour to thicken sauces, soups, and stews in your cooking. Cornstarch has some added advantages over flour–it is tasteless, gluten-free, and remains clear, so it will not make your dish cloudy as a roux would.

How to Use Cornstarch

Start by creating a mixture of equal parts cold water and cornstarch, stirring well to make sure it is smooth. This forms what is referred to as a “cornstarch slurry” and is one of the most popular methods to thicken sauces for home cooks. A cornstarch slurry is not the same as a roux as roux are traditionally always flour and butter, but they can both accomplish similar goals in your kitchen.

Stirring your sauce over medium heat, whisk in 1 Tablespoon of your slurry thickener for every cup of sauce. If done correctly, your food should retain its full flavor and still be just clear as to when you began.

Is Arrowroot a Substitute for Cornstarch?

You may have also heard of arrowroot, a starch that functions similarly to cornstarch in thickening soups and sauces. You can use the same instructions for adding arrowroot as a thickening agent as you would cornstarch.

However, while arrowroot has the added benefit of being GMO-free, it does not combine well with food with dairy, so best to avoid it in your more hearty dishes.

Xanthan gum

Xanthan gum is an ingredient used to thicken sauces and other foods. It is gluten-free and makes liquids have a thicker consistency without altering their flavor. Xanthan gum can be bought in most stores or online.

How to Use Xanthan Gum

To use xanthan gum, you want to whisk together a ratio of 1/4 teaspoon xanthan gum in 1 Tablespoon of hot water. Typically you want to add 1 Tablespoon of the xanthan mixture per cup of sauce, but xanthan gum is powerful. A little can go a long way, so add your mixture in slowly and test it periodically. If you add too much xanthan gum, it can become gloopy and mucus-like. Once the sauce has reached your desired consistency, pour it through a strainer to capture and remove any extra lumps you may have missed.

Xanthan gum is best for thickening gravy or syrups. It is the most potent thickening option on this list and should only be used in the most challenging cooking situations.

Egg yolk

The act of heating egg yolks denatures the proteins allowing them to be combined with something else when they cool and reform. Depending on how thick you want your sauce to be, you can add more or fewer egg yolks. But a good rule of thumb is to start with one or two.

How to Add Egg Yolk

The trick to adding egg yolk to thicken sauce is ensuring that you do not accidentally cook some scrambled eggs instead. To avoid doing this, put your yolks into a separate bowl and gradually stir in 1 cup of the hot sauce you want to thicken. This will heat the egg yolks slowly, and you should avoid cooking them. Once the yolks have been combined smoothly, you can stir them into the pan with the rest of the sauce. Make sure to whisk it well while adding it in.

Adding egg yolks to a sauce using this method is also a way to fix a broken sauce. A broken sauce occurs when you add fatty ingredients to your sauce or soup too quickly, causing the components to separate out and curdle rather than becoming rich and smooth as you intended.

Tomato Paste

Tomato paste works well for tomato-based pasta sauces and stews. While it will taste better the earlier that you add it due to the sweet caramelizing effect it can have when heated, tomato paste can also be a handy last-minute addition to make your food thicker.

How to Add Tomato Paste

To improve texture with tomato paste, simply add 1 or 2 Tablespoons to your sauce while simmering in the pan. After it has been thoroughly stirred in, you can test the thickness of the sauce with the back of a spoon before deciding if you want to add more.

Tomato paste is best for dishes that already contain tomatoes, such as spaghetti sauces and chili, as it will simply add to the flavor while also making it thicker. However, it should be avoided in cream sauces, gravies, and dessert dishes.

What About Cream of Tartar?

Tartar sauce is not actually an ingredient you should be used to thicken sauce. While both tartar sauce and cream of tartar can be used in cooking to change the consistency of food, it is not recommended that you use either to thicken sauce.

How do you thicken a sauce naturally?

If you want to thicken your sauce naturally without other ingredients, you will want to reduce it. A reduction is a process of continuing to heat your sauce to evaporate excess liquid, causing it to become thicker.

What is a Reduction?

The final option to thicken a sauce is simply not adding a thickener but instead making a reduction. As a home cook, you have probably often heard the term “reduction” but may not actually know what it means. I am happy to tell you that it is a relatively simple procedure.

A reduction in cooking means that you are heating the dish to reduce the amount of water content and increase the consistency of the food. Reductions are common in recipes and can be seen in everything from sauces, soups, stews, and even some dessert recipes!

How do you reduce sauce?

To perform a reduction, simply heat your sauce over medium heat until it reaches your desired thickness. You will want to monitor the sauce and continue stirring it to make sure it doesn’t burn. You can test the consistency of the sauce using the back of a spoon and sample a taste this way. A sauce that has been reduced tends to have a more concentrated flavor profile as well.

Because of this reason, a reduction is a good option for cream or pasta sauces but should not be done with anything with high salt content, such as soy sauce. Reducing sauces with high salt contents will often leave them too salty and unpalatable.

How do you thicken a healthy sauce?

If you want to thicken a healthy sauce, you should avoid options like a roux that adds unneeded butter. For a healthy sauce, as long as it is not too salty, you are best off using a reduction to thicken your sauce.

How to thicken pasta sauce

If you are working with a spaghetti sauce or other tomato-based sauces, you should, of course, go with tomato paste. The earlier you add it to the dish, the better it will taste, and add the perfect note to your meal.

Your pasta water. There is a secret trick to the perfect pasta sauce, and I guarantee it’s an ingredient you have access to. When you boil your noodles, starch is shed into the water. Using that water adds just a bit of starch to your sauce, making for a perfect texture.
Of course, that should be done as you are creating the sauce. Adding water to a sauce, you have already made will thin the sauce.

How to thicken stew

To thicken a stew, you should either go with a roux or tomato paste depending on what flavor notes you would like to add to the dish. A roux can make it heartier, while tomato paste can add a bit of sweetness to the meal.

How to thicken soup

To thicken soup, you can either make a reduction or add a thickening agent to enhance the flavor. If the soup has tomatoes, you can try tomato paste. For a clear soup, you should use cornstarch. For a hearty cream-based soup, you can’t go wrong with a roux.

How to thicken au jus

Since au jus is a more transparent sauce, you should go with cornstarch or arrowroot as your thickening agent. This will keep the clarity and the great flavor of your meal.

Can you use instant potatoes to thicken gravy?

Yes, you can use instant potatoes to thicken gravy. While over medium heat, add 1 Tablespoon at a time while mixing well until you reach the ideal thickness. Be aware that using potatoes to thicken gravy will change the texture of the dish. If you want to keep the original texture, I recommend using a roux instead.

Which thickener should I use?

Now that we have broken down the thickeners options and how to use them, you must now decide which option is best to use. Choosing a thickener to use depends heavily on what you have available to you and how you want to affect the dish’s taste.

For cream-based and other white sauces, a reduction or a roux is the best bet. A reduction would enhance the current flavors, while a roux would add more fat and give the dish a heartier flavor. You also don’t have to worry about a roux giving the sauce a cloudy appearance as it will be hidden in the delicious murky depths of the cream sauce.

A roux is also a great way to go for gravy and other brown sauces intended for meat. Gravies stand up well to the flavor boost of a roux and can enhance the dish nicely. If your gravy is particularly weak and runny, then xanthan gum is the way to go. If, however, the food contains tomatoes, you should choose pasta sauce instead to give it an extra sweet pop for your taste buds.

If you are working with a spaghetti sauce, stew, or other tomato-based sauces, you should, of course, go with tomato paste. The earlier you add it to the dish, the better it will taste, and add the perfect note to your meal.

How do You Thicken Soy Sauce?

For soy sauces and other salty liquids, you likely want to choose cornstarch or arrowroot as they will keep the clarity of the sauce and not alter the flavors. You mainly want to avoid performing a reduction as it will make the saltness unbearable.

How do You Thicken Chocolate Sauce?

A reduction is the safest bet for dessert sauces as you don’t want to accidentally introduce other flavors. Keep in mind that you should test it periodically with the back of a spoon for the thickness and ensure you do not concentrate the sweetness too much.

When All Else Fails

Barbeque sauces and other condiment-style liquids can be thickened with most of the above methods. Choose whichever tools you have on hand that you believe fits the flavor you are aiming for. Whether that is a hearty roux, a sweet tomato paste, creamy egg yolk, a concentrated reduction, or a neutral starch. You should now be prepared to handle even the worst of your thin sauce cooking confrontations.

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