How to thicken soup

Thickening soup can make it much more filling and satisfying. There are plenty of options to thicken soups, and you probably already have the ingredients in your kitchen. If you’ve made a soup and think it looks a little runny, you can add a thickening agent, such as starch, to adjust the consistency or add chopped vegetables to bulk up a thin broth.

What can be used as a soup thickener?

Starchy foods are ideal as soup thickeners. The best types of starches to use are those that expand when in contact with water and bind together to provide a richer consistency. Flour, potato, lentils, cornstarch, rice, pasta, noodles and bread all contain the necessary starches for thickening soup.

Whichever thickener you choose, it is important to note that the best results are likely to come from broken-down starches. In other words, you can’t just throw a slice of bread into your soup and expect it to become thicker. You should break it down into breadcrumbs before adding it as a soup thickener. The same goes for pasta. Small pasta shapes with a large surface area, such as Risoni or Stelline, for instance, will work better than penne or spaghetti. Even better, flour or potato starch will combine with the liquid of a soup, offering not only a thicker soup but an even consistency.

How to thicken soup with flour

When thickening a soup with flour, it’s best to sprinkle it gradually over the soup, using approximately one teaspoon at a time. Stir continuously as you add the flour to prevent clumping. Maintain high heat to keep the soup simmering, allowing the flour to swell upon contact with the liquid and effectively thicken the soup.

How to thicken soup with potato

To thicken soups like vegetable soup or fish chowder, finely diced potatoes work well. For a smoother integration, grating the potato is the best method. After grating, you can add potato to the soup, but it will still take some time to give off all of its starches. You can release more starch and speed up the process by placing grated potato into warm water and rubbing it together by hand before adding it to your soup.

How to thicken soup with cornflour

Cornstarch is even better at thickening soup and sauces than plain flour. However, cornstarch can be more prone to creating lumps if you add it directly into a liquid. To prevent this, heat butter or oil in a pan, then stir in your cornflour. The fat should combine with the cornflour to form a paste or roux. With the two ingredients thoroughly combined, you can add the paste to your soup without the risk of lumps.

How to thicken tomato soup

Tomato soup can be thickened using any of the methods mentioned above – adding a cornflour roux, grated potatoes or plain flour. However, there are some more traditional options. One good way to thicken tomato soup is to add tomato purée, which will add flavour as well as thickness.

You can also reduce your tomato soup, which simply means to continue simmering it without a lid. Reducing a dish means lowering the amount of water through evaporation. After a few minutes of slow boiling, water will escape from your tomato soup as vapour. What remains in your pan will become progressively thicker and more dense. Keep stirring the soup when using this reduction method, as this will help prevent the soup from sticking to the bottom of your pan.

How to thicken vegetable soup

Vegetable soup can be thickened by reducing or adding any of the common thickening agents – cornflour, wheat flour or potato starch. For a heartier vegetable soup, you can slice or cube potatoes instead of grating them. Yams, parsnips and squashes are also great choices for thickening soups. Alternatively, try this Mulligatawny Style Soup and Spiced Broccoli recipe, that uses red lentils as a thickener.

FAQs

How do you thicken watery soup?

Add starch to a watery soup to make it thicker. Flour, cornstarch or fine potatoes are all good options.

Is it better to thicken soup with flour or cornstarch?

Either way is good, but to avoid lumps, make a roux with cornstarch. The extra preparation step can be worth the effort.

Can you thicken soup without cornstarch?

If you don’t have cornflour to act as a thickening agent, then use plain flour. You can also make a roux with it for more consistent results.

Tools to use for thickening soup

When thickening soup, stirring helps to spread the starches around and avoid lumps. As such, your best tool will be a wooden spoon.