Why Is My Soup Not Thickening? How To Fix It

You’ve made a soup, followed the recipe, used all the right ingredients, and it still seems thin and watery? Luckily for home chefs, there are several ways you can save a thin soup, depending on what’s to hand in your kitchen and how much time you have. I’ve got several methods for fixing a soup and bringing it to thicken up nicely without changing the taste too much.

Soup may not thicken if it contains too much liquid. By raising the temperature to a medium-high and removing the lid, you can evaporate some of the excess stock. Other methods of thickening soup include using flour, cornstarch, dairy products, blending or mashing your soup, and adding okra or starchy vegetables.

There are a few ways to thicken up a watery soup, and they will leave you with different results. I’ve listed some tried and tested methods below and their effect on your soup, including how it looks and tastes. Some are quicker solutions, while others will take time but add to the flavor of your dish, while others will change the texture.

Why Is My Soup Not Thickening?

The problem might be because you added too much stock or water in proportion to your other ingredients, or perhaps you added frozen vegetables, which released extra water into the soup. 

Whatever the reason, you probably want to thicken it up. How to thicken a soup will depend on what you have in your cupboards or fridge, how much time you have, how salty or strongly flavored your soup is, and whether you can use gluten-based ingredients.

I’ve gone through a few methods below to help you get your soup nice and thick, and you can choose the one that seems most appropriate for the kind of soup you are making.

Some methods, such as blending or mashing, will not change the taste of your soup but will affect the texture, so if that won’t work for the recipe, consider adding starch instead.

Vegetables are another excellent way of thickening soup, especially if you add starchy vegetables already in the soup, such as potatoes. It’s a good idea to match the thickening agents you use with the type of soup.

For example, a potato and leek soup could be thickened with potato or potato starch, a chicken and rice soup could use extra cooked rice for thickening, and a gumbo-style soup could be thickened with additional okra. See my post on how to add potatoes to soups and stews successfully.

Will Soup Thicken As It Simmers?

Soup will thicken as it simmers if it has the right ingredients to help it get thicker as the water evaporates. Soup with starchy ingredients like flour, vegetables, or natural sugars will thicken but clear, watery soups and broths will not thicken much.

If you have time to simmer your soup for longer, simmering could be worth a try. It’s a simple way to evaporate excess water or stock which is what waters down the soup.

A longer cooking time might not be appropriate depending on how watery your soup is and your ingredients. Overcooking your soup could also be an issue as the ingredients will get softer.

As the extra water slowly bubbles away, you should be left with a thicker, more tasty soup as the flavor becomes more concentrated.

Remember to remove the cover from your pot – this will stop excess moisture from returning to the soup. If you choose to do this, keep watch that your soup doesn’t start to boil or burn, and stir it every so often. Check out my post on whether you can simmer a soup for too long and when it’s a bad idea to do so.

If simmering doesn’t thicken your soup then you probably want to try adding some extra ingredients. Consider some of the options from below based on the items already in your soup. Adding a starchy slurry is a popular go-to method as well as blending a part of your soup and adding it back in.

How Do I Make My Soup Thicker?

Try adding a starchy slurry mix (cornstarch or flour) and cooking a little longer to allow the starch to thicken the liquid. Adding starch will change the flavor and texture, so avoid adding too much at first. Allow time to cook the thickener into the soup.

To add flour or cornstarch: Mix the flour into a paste/slurry and add a little of this paste to your soup, stirring it in well.

Mix approximately 3-4 tablespoons of soup with 1 tablespoon of flour or cornstarch in a small separate bowl, ensuring that it is a smooth paste with no lumps. You want it to be completely smooth, as adding flour direct to a soup will leave you with clumps of gluey flour in the soup.

Add the mixture to your soup, and bring it back to a simmer while stirring for a few minutes. The soup should thicken during this process. If your soup is still too thin after adding the slurry, you can add more.

Using wheat flour will cloud your soup and give it a more milky, creamy appearance. This cloudiness is fine for blended soups like cream of mushroom or chicken, but if your soup should remain clear, it’s better to use cornstarch for this process.

Judge the taste of the soup – it may need some extra cooking to “cook out” the raw floury flavor. It will add a slight taste, but hopefully not too much to be overly noticeable.

How Do You Make Soup Thicker Without Flour?

If you are unable to use flour, either because it would change the color/texture of your soup in a way you don’t like or for dietary reasons, there are other starches you can use as a thickener.

  • Blend all or part of the soup – remove a cup or two of soup and blend it or mash it up. Add this thick liquid back to the soup to thicken the whole thing. Alternatively, just blend it all for a smooth soup.
  • Cream or yogurt – adding cream or yogurt at the end of the cooking process can add rich, creamy thickness to a blended soup.
  • Potato starch – potato starch is nearly tasteless and makes a good thickener for soups and stews. Don’t mix it up with potato flour – the potato starch is made from dehydrated cooked peeled potato slurry and is a fine powder much like cornstarch. Potato flour is ground from whole dried potato.
  • Cooked rice – this is best for a blended soup, as you add the cooked rice directly into the soup and blend it in. It doesn’t provide a lot of thickening, so it’s suitable for soups that are only a little thin and those that already have rice as the main ingredient.
  • Beans or lentils – an excellent way to add body to soups that already have legumes. Blend some cooked beans or lentils with some of the soup liquid, and stir it into your soup.
  • Cauliflower – this is a good choice if you’re low-carb cooking. Blend cooked cauliflower very well with some of the soup liquid, and add this back to your soup.
  • Okra – traditionally used to thicken gumbo, add chopped okra ten minutes before the end of the cooking process, and let it naturally thicken your soup.


Hopefully, you now know why your soup is not thickening. You can thicken a soup by blending it, if that is suitable, and adding a thickening agent such as flour, starch, cooked beans, or lentils. Another thickening method is to continue to simmer the soup for longer uncovered to evaporate some of the water, and this will have the added benefit of intensifying the flavor.

Some thickening agents can change the color of the soup, so if your soup needs to remain clear, use ingredients like cornstarch or okra that will not cloud the liquid.

Have any questions? Ask me in the comment section below and I’ll get back to you.

Tom Hambly

Tom Hambly is the founder of Boss The Kitchen. With a background in cooking and building websites, he enjoys running this site to help other cooks improve. About Tom Hambly.

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