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How To Thicken Tomato Soup | The Best Way

Tomato soup doesn’t always turn out to be the texture you want. When that happens, it may be necessary to rely on other methods to thicken it up. But which way is the best?

The best way to thicken tomato soup is by adding flour since it won’t change the flavor much. However, do not add it directly, or clumping will occur. Instead, whisk some of the soup with a few tablespoons of flour in a separate bowl. Then, slowly whisk the mixture back in until it reaches the desired consistency.

The rest of this article will answer in detail many questions related to this topic, including how to make tomato soup creamy, how to thicken it without flour, whether it’s better to thicken with flour or cornstarch, what to do if your tomato soup is too watery, and more.


How To Thicken Tomato Soup Without Flour

If your soup has come out too liquidy when you were going for thick and creamy, and you don’t want to use flour to thicken it, don’t worry. Here are 7 different ways to thicken tomato soup without flour:

  1. Add starch. Cornstarch, potato starch, and tapioca starch are all great thickening agents. They’re also cheap and easy to find online, such as this 100% pure cornstarch brand found on Amazon. It’s all-natural, gluten-free, and has twice the thickening power as flour. Dilute a tablespoon of your chosen starch with cold water, and mix it into the soup when it’s nearly done cooking. Stir until it reaches your preferred consistency.
  2. Add potato flakes. Adding instant mashed potatoes to your soup is an effective way to thicken it. Just add a tablespoon of instant mashed potatoes to the soup and stir until it reaches your desired consistency. Bob’s Red Mill Potato Flakes would be a great choice. It’s inexpensive, all-natural, and will be sure to make your soup creamy too.
  3. Add eggs. This is a great low-carb, high-protein option. Whisk two eggs in a bowl and then add a ladle of soup to temper it. Add the mixture to the soup and stir until thickened. Don’t boil the soup after adding the eggs, as this will scramble them. If you prefer a richer, creamier soup, use only the yolks. If you want something lighter, use only the whites.
  4. Add cheese. Blending cheese such as mozzarella, cheddar, or American into the soup can thicken it and add wonderful, rich flavor. You can also bring the soup to a low simmer and add the cheese a little at a time, whisking until fully incorporated to prevent clumps.
  5. Add white rice. Add ¼-½ cup raw white rice to 8 cups of soup, and simmer it for around 20-30 minutes, then puree. This will result in a thick and hearty soup.
  6. Add cashews. This method will also add a wonderful nutty flavor to the soup. Blend a cup of roasted cashews with a cup of vegetable broth in a food processor, pulsing until creamy. Add to the soup and stir until thickened. 
  7. Add beans. Beans can be an excellent source of added protein and fiber and add body and flavor to your soup. Blend softened beans in a blender or food processor until smooth, then add to the soup and stir until combined. It’s up to you what beans you use; however, white beans go best with tomato soup for their subtle flavor.

Is It Better To Thicken Tomato Soup With Flour or Cornstarch?

It’s better to thicken tomato soup with flour, as the acidity from the tomatoes may cause the cornstarch to lose its efficiency as a thickener. However, it also depends on personal taste and preference.

Cornstarch doesn’t hold up well as a thickener in acidic soups such as tomato soup. Therefore, it’s best to go with flour. 

However, you may prefer flour over cornstarch for its heartier flavor and added protein. Corn starch thickens more quickly and has a neutral flavor, while flour takes longer to thicken and has a fuller flavor. 

Flour will also give the soup a more opaque look, while cornstarch will give it a slight sheen. Furthermore, there’s a difference in how much you need to heat and cook the soup for each thickener. 

Flour begins thickening at a lower temperature of 126 °F (52.22 °C), but it needs to be cooked much longer, for around 20-30 minutes. Cornstarch needs to reach 180 °F (82.22 °C) to start thickening but only needs to cook for around a minute.

What Is the Healthiest Way To Thicken Tomato Soup?

The healthiest way to thicken tomato soup is by adding extra veggies. Not only will it give the soup a thicker texture and richer taste, but it’ll add nutrients and fiber too. 

Root vegetables such as sweet potatoes, carrots, squash, and pumpkin are wonderful thickening agents due to their high starch contents. Carrots are especially good in tomato soup, as they complement the flavor of the tomatoes very well. Other vegetables you can use include potatoes, parsnips, beans, peas, cauliflower, or corn. 

To use veggies to thicken tomato soup, make sure they’re mashed, mix them into the soup, and let simmer until the soup thickens. Or you can chop up your chosen veggies into chunks and cook the chunks in with the soup. This will cause the veggies’ starches to seep into the soup, adding more thickening power. 

After cooking, you can mash up the veggies into the soup. To make sure the soup is creamy, smooth, and thick, you can blend the soup and the veggies up together before serving.

Adding beans is also another incredibly healthy way to thicken up your soup. Beans will add protein, fiber, iron, magnesium, potassium, zinc, folate, and free radical-fighting antioxidants. You’ll be getting all these health benefits without even noticing it, along with a thicker soup.

Will Cooking Tomato Soup Longer Thicken It?

Cooking tomato soup longer will thicken it. Letting the soup simmer longer will evaporate the excess liquid, thereby thickening the soup and concentrating the flavors. 

Cooking tomato soup longer is a great way to thicken it without the use of any thickening agents. If you wish to thicken the soup in this way, follow these steps:

  1. Make sure the soup is uncovered.
  2. Boil the soup.
  3. Reduce heat and let it simmer.
  4. Simmer until it reduces to the desired consistency. 
  5. Stir regularly to keep the soup from burning.
  6. Remove soup from heat and let sit for a few minutes.

Keep in mind this method will also concentrate the flavors in the soup. To combat this, taste the soup occasionally as it simmers to ensure it remains the flavor you want. 

Woman cooking two pots of tomato soup on the stove
Patience is sometimes all we need for thicker heartier soups.

Does Tomato Soup Thicken As It Cools?

Tomato soup can thicken as it cools if it has added starches or flours, which congeal when cold. The added starches continue to soak up liquid even after the soup stops cooking, resulting in a thicker soup once cooled.

Flour thickens more as it cools. Thus, it may be better to stop cooking soup thickened with flour when it’s a bit thinner than its ideal consistency, as it’ll become thicker as it cools.

The same goes for other added starches such as cornstarch, potato starch, tapioca starch, and so forth. Just like flour, these will continue to thicken as they cool. I recommend taking the soup off the heat when it’s a little thinner than you want it to be, as it’ll continue to thicken afterward.

This is due to the molecules of the starches and fours. These molecules contribute to thickening at high temperatures and bond together when cooled, becoming solid. There’s also less heat energy moving them around, causing them to remain in a liquid state.

Does Milk Thicken Tomato Soup?

Whole milk can thicken tomato soup; however, it’s best used to add creaminess and rich flavor rather than bulk. This is because milk isn’t a thickening agent in itself but only becomes thicker once heated and its moisture has evaporated.

If you wish to thicken soup using full-fat milk, add a few splashes into the soup when it’s nearly finished cooking and simmer for ten minutes, being careful not to make it boil.

Adding yogurt can also thicken the soup effectively if you don’t mind the tangy flavor. A spoonful of very thick yogurt stirred into the soup and simmered for not more than ten minutes can thicken the soup up nicely and make it creamy. 

Be sure not to boil the soup after adding the milk, cream, or yogurt, as that can result in curdling or splitting.

How To Make Tomato Soup Creamy

Here are four foolproof ways of making your tomato soup creamy (You can also do a combination of these methods together to make it as creamy as possible):

  1. Add cream. Heavy whipping cream, coconut cream, half and half, and whole milk all work for this. Stir in the cream after blending up the tomatoes, then add as much as is needed for your preferred level of creaminess. Keep in mind that the less fat the cream has, the less creamy the soup will taste, as the fat is the main cause of the rich texture. 
  2. Blend the soup. Blending the soup is essential for a smooth, creamy texture, as it’ll get rid of all the little rough bits of tomatoes or spices. An immersion blender, regular blender, or food processor will all get the job done.
  3. Strain the soup. Straining the soup can also make it more creamy, as it’ll strain out any rough bits that can’t be blended. It’s best to do this after pureeing the tomatoes to ensure no solid bits are left; then, add your cream. For the creamiest soup possible, try both straining and blending the soup.
  4. Add cream cheese. In place of cream, you can add cream cheese for an even richer, more flavorful, and creamier soup. To do so, add 8 oz (226.79 grams) of softened cream cheese to 3 cups of tomato soup, and blend together.

Related How to Fix Grainy or Gritty Cheese Sauce (In 3 Easy Steps).

What Can I Do if My Soup Is Still Too Watery?

If your tomato soup is too watery, you can simmer the soup uncovered until the excess water evaporates to thicken it up. You can also add a flour roux, potato flakes, or starch if time is a factor.

Starches would be the best way to thicken up a watery soup, as they do an excellent job of absorbing excess liquid. They’ll absorb the wateriness of the soup and expand to add bulk and richness.

You can also add tomato paste to thicken it. Its concentrated flavor will add body to the soup as well as depth. However, it’s best to add the paste before seasoning the soup, as it may cause the flavors to become imbalanced. Therefore, add the paste only a little at a time, tasting after each addition to ensure it doesn’t become too concentrated.

To make a flour roux, melt some butter, add an equal amount of flour, and stir until smooth. Ladle a bit of hot soup into the mixture so that the starchy taste of the flour gets cooked out. Then mix it into the soup and stir until it reaches the desired consistency.

A roux is super simple to make.

Another great method to try for watery soup is to add bread, which will absorb the liquid and add hearty bulk. For this, take some slices of French or Italian bread, make sure they’re dry (you can also toast them), and then blend them into the soup. Add as much bread as you like for your desired consistency. This may make the soup a bit chunky, but it’ll get rid of the wateriness.

Final Thoughts

When your tomato soup doesn’t turn out to be the way you want, all is far from lost. There are many different methods you can try to obtain your desired results. And many of them add even more flavor, depth, and richness to the soup than before.

Hopefully, you found some of these tips and suggestions helpful in your cooking.

For more, don’t miss How Long Does Tomato Sauce Last? | Unopened vs. Opened.