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7 Best Ways to Thicken Tomato Sauce

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Everyone loves making their own sauces and it is becoming more and more popular. What is essential for sauce-making is achieving the correct consistency! More often than not, homemade sauces end up not being thick enough.

With tomato sauce specifically, more often than not it comes out watery.

So, what are the best ways to thicken tomato sauce? We highly recommend reducing the sauce over heat until you’ve reached the desired consistency. Alternatively, you can add cornstarch, arrowroot powder, mashed vegetables, a roux, or an egg yolk.

Today, we will have a look at the best methods to thicken tomato sauce that is homemade.

We will discuss the pros and cons of each method, as well as give thorough instructions on how to do so. Now, you don’t ever have to worry about runny tomato sauce again!

What is the Correct Consistency for Tomato Sauce?

The consistency of any sauce will depend on what you want to use it for. Most sauces need to have a relatively thick consistency.

This can be tested by adding a dollop of sauce on a plate; the sauce shouldn’t run around on the plate, but it also shouldn’t be as thick as a paste is.

A lot of sauce recipes already have the correct consistency for what they are usually used for.

For example, a béchamel sauce (white or cheese sauce) will have a thick and luscious consistency for lasagna, or macaroni and cheese, while a spaghetti sauce will have a more runny and fluid consistency.

Tomato sauce specifically has a wide variety of uses and thus a wide variety of consistencies. You have thicker versions that are used as dipping sauces, or you have runnier consistencies that can be used for something like a pizza sauce.

That is why it is difficult to find a good recipe that has the perfect consistency for your desired use. Even if you do find one, a lot of environmental factors can lead to the consistency not becoming what you want it to be.

The thicker the consistency of your tomato sauce, the deeper the flavor will be. This is why tomato paste, which has a very thick consistency, has an extremely deep, concentrated, and intense flavor.

How to Thicken Tomato Sauce Without Tomato Paste

So, now you’ve tried a recipe and the consistency is not close to what it needs to be! You might be realizing that it’s more difficult to thicken sauces than to thin them down. 

The most common way is by incorporating tomato paste into the runny sauce. This method is great because it helps deepen the tomato flavors while also thickening the sauce.

thicken tomato sauce

Begin by adding 1 tablespoon at a time as you reheat your tomato sauce, letting it cook, and then tasting before adding any more tomato paste. The amount you use will vary depending on how much tomato sauce you have.

However, as life goes, when you desperately need tomato paste, you’ve just run out! Luckily, there are tons of other ways to help thicken your tomato sauce!

You can choose any of the following methods depending on the amount of time you have to thicken the sauce and the ingredients available to you.

Simmering / Reducing

This is by far the easiest method to follow when it comes to thickening any type of sauce, especially tomato sauce. 

Tomatoes have a lot of water in them which is released when they are cooked. The water, unfortunately, is what affects the consistency and makes it runny. An excessive amount of water is also what dilutes the flavor of the sauce.

Again, the thicker the sauce, the deeper and more intense the flavor will be.

In order to get rid of the excess water, you can simply continue cooking the tomato sauce until the desired consistency is achieved, meaning the correct amount of water has evaporated during cooking.

The downfall to using this method is that it can take quite some time to reduce, especially if the consistency is extremely runny or if you want to achieve a very thick consistency.

Regardless, if you have some time on your hands, it is a fantastic method as you can simply leave the sauce on the heat and allow it to simmer – no extra steps, no extra equipment or ingredients are necessary.

By allowing the sauce to reduce, you are concentrating the natural flavors without affecting them with that of other ingredients.

Reduces and concentrates the natural tomato flavors. The tomato sauce will be unaffected by the flavors of other ingredients.This is a time-consuming method and can take up to an hour depending on how runny the consistency is or how thick it needs to get.
No additional ingredient is needed.There is a possibility of the sauce burning at the bottom of the pot due to prolonged cooking.
No extra equipment is needed.
An easy method to thicken the consistency without any effort.

How to Reduce Tomato Sauce

  1. Test the consistency of your tomato sauce and determine how thick you want it to be.
  2. Leave the sauce on medium-low heat and continue simmering it, uncovered, to allow excess moisture to evaporate and the sauce to thicken.
  3. Continue cooking the sauce for 10-20 minutes or until the desired consistency is achieved.
  4. Make sure to stir the sauce every 5-10 minutes to prevent it from burning at the bottom.

Add a Roux

A roux is a mixture of butter and flour that has been cooked. The roux is usually a starting base for many sauces and helps thicken with ease!


Roux’s can be made with different ratios that will affect the consistency. The ratios are as follows:

  • A thin roux (to make thinner sauces) uses a 2:1 consistency ratio, meaning 2 parts butter, and 1 part flour.
  • A medium roux (to achieve medium consistencies) uses a 1:1 ratio of butter and flour.
  • A thick roux (to make extremely thick sauces like béchamel) uses a 1:2 consistency ratio, meaning 1 part butter to 2 parts flour.

We would recommend using a 1:1 ratio of butter and flour to help thicken your tomato sauce. No matter what consistency it is at, it will help thicken it without making it too thick. You can use 1 tablespoon of each per cup of sauce you have.

Making a roux is easy, but incorporating it into an already-made sauce is more difficult. You have to follow very precise steps to prevent lumps from forming and the sauce from thickening incorrectly.

A very effective way to thicken tomato sauce and you can use different ratios for different consistencies.Very easy to create lumps if you don’t follow the steps correctly.
Making a roux is very easy if the correct steps are followed.Extra ingredients and equipment are needed.
Doesn't affect the flavor of the sauce if you bring it to a boil (which helps cook out the flour taste).
Very time-effective way to thicken your tomato sauce.

How to Thicken Tomato Sauce with a Roux

  1. In a saucepan, melt 1 part butter. Remove the pan from the heat and whisk in 1 part flour until a thick paste forms.
  2. Still off the heat, slowly whisk in the thin tomato sauce. Start by adding 1/8 cup at a time, whisking well between each addition.

If you add too much liquid without incorporating it properly into the roux, lumps will form which are very difficult to remove.

  1. Once all of the sauce has been incorporated, put the saucepan back onto the heat and bring the sauce to a boil.
  2. Reduce the heat and continue simmering the sauce until has reached the desired consistency, about 5-10 minutes.

Make sure to continuously whisk to prevent the sauce from burning at the bottom.

Add Cornstarch

Cornstarch is an age-old thickening agent that is used in thousands of recipes! Although it isn’t necessarily added as the primary thickener, it does make a fantastic backup plan.


Cornstarch has a very neutral flavor that can be cooked out by boiling the sauce. It also doesn’t affect the color of the sauce, it is very easy to incorporate, and it doesn’t affect the texture.

If however, you overcook the sauce, the texture will change a bit to an almost grainy-like consistency.

An extremely easy method to use.Extra ingredients required.
Extremely quick to do.There is a possibility that the texture can change when overcooked.
Doesn’t affect the taste or color of the sauce.

How to Thicken Tomato Sauce with Corn Starch

  1. Add 1 teaspoon of cornstarch to every 1 cup of tomato sauce. Whisk in the cornstarch until it has completely dissolved into the sauce.
  2. Simmer the sauce on low heat until it thickens, about 5-10 minutes.

Add Arrowroot Powder

Arrowroot powder has become especially popular over the past few years, despite being an ancient ingredient. This powder is obtained from a root vegetable and, like cornstarch, has thickening characteristics.

arrowroot powder

Arrowroot is completely flavorless and odorless, even more so than cornstarch. It will not affect the taste of your sauce or even the smell.

Make sure you only add the slurry mixture to a barely warm sauce, otherwise, it can ruin your texture. Do not allow your sauce to boil under any circumstances!

Very easy method to incorporate.Additional ingredients required that can be difficult to find.
Not time-consuming.Texture can change when overcooked.
Doesn’t affect taste, color, or smell.

How to Thicken Tomato Sauce with Arrowroot Powder

  1. Combine 1 tablespoon arrowroot powder with 1 tablespoon water. Whisk them together until a smooth slurry forms.
  2. Heat your tomato sauce over low heat and add your arrowroot mixture to the sauce.
  3. Whisk until the two mixtures are completely incorporated.
  4. Continue cooking your tomato sauce until it reaches the desired consistency.

Add Mashed or Pureed Vegetables

Despite being a fantastic method to thicken your tomato sauce, this method will only work with recipes that contain vegetables, otherwise, the taste of the sauce will be completely changed.

Let’s say for example you have potatoes with your tomato sauce or in the recipe, by simply adding 1-2 tablespoons of mashed potatoes, you can thicken your sauce effortlessly.

You can use any type of vegetable puree, as long as it has a nice thick consistency. Starchy vegetables work best as the starch helps thicken the sauce

You can also of course add different vegetables to change the flavor of your tomato sauce, so instead, you could be making a roasted pepper and tomato sauce, or a carrot and tomato sauce. 

Mashed vegetables will change the texture of your sauce, so you also might want to blend it smooth.

Even though this method does alter the taste, texture, and even color of your tomato sauce, it is still an effective thickening method and does make a mouth-watering sauce!

Does affects the flavor, texture, and color – which can be fantastic if that is the goal.Extra ingredients and equipment are needed for this method.
Great way to use leftover ingredients and vegetables.Does takes longer than other methods.
Will change the texture, flavor, and color depending on which vegetables you use.

How to Thicken Tomato Sauce with Mashed Vegetables

  1. Make a thick puree with the vegetable of your choice. Make sure to cook out excessive liquid (water) before using the puree or mash in your tomato sauce. You will only need 1-2 tablespoons of mash per 1 cup of tomato sauce.
  2. Heat the tomato sauce over low heat and add the mashed vegetables.
  3. Whisk together the 2 mixtures and adjust the seasoning as needed.

Add an Egg yolk

Adding even a single egg yolk will help thicken your sauce a lot! This method does have a few steps involved, but is extremely quick and effective – and, you probably always have an egg or two lying around somewhere!

egg yolk

Egg whites have binding characteristics but not thickening. So if you were to add the whites, they will cook in the hot sauce which will change the texture. However, they won’t thicken the sauce at all!

Only use egg yolks as they will thicken and enrich the tomato sauce.

Very convenient to use an egg yolk as you will almost always have an egg at home.Easy to cook the egg yolk and not incorporate it correctly, which then will change the texture without thickening your sauce.
A very effective way to thicken your sauce without changing the flavor or texture.
Enriches the sauce.

How to Thicken Tomato Sauce with Egg Yolks

  1. Combine 1 egg yolk with ½ cup lukewarm tomato sauce.
  2. Whisk until the egg yolk is completely incorporated into the sauce. Do not use heated sauce as it will cook the egg, creating scrambled egg pieces in your sauce instead of thickening it.
  3. Add the egg yolk mixture to the rest of your lukewarm tomato sauce.
  4. Whisk the two together well to incorporate the egg into the rest of your tomato sauce.
  5. Slowly bring the sauce to a simmer without boiling it while whisking continuously.

Related Questions

Now that we’ve gone over some of our favorite methods for thickening tomato sauce, here’s a few more questions we thought you might’ve had while reading this article!

Why Is My Sauce Watery?

Any sauce that is watery is due to excess moisture. This can either be due to incorrect recipe ratios, insufficient cooking times, or in the case of a tomato sauce, an extra juicy tomato!

Can I Use Flour to Thicken My Sauce?

Do not use flour by itself to thicken a sauce. Rather make a roux that can be incorporated more easily into the sauce. The flour can easily create lumps and affect the flavor.

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