How to Thicken Soup: 7 Easy Ways That Actually Work

You made a pot of homemade soup, tasted it, and realized it is much thinner than you wanted. Fortunately, watery soup is usually easy to fix.

Learning how to thicken soup comes down to choosing a method that fits the soup you are making. A flour or cornstarch slurry works quickly, a roux adds richness, potatoes add body, and sometimes all your soup needs is a little more uncovered simmering.

Quick Answer: How to Thicken Soup

For most soups, start with one of these simple fixes: stir in a flour or cornstarch slurry, blend part of the soup, add mashed potato or potato flakes, stir in cream, make a roux, or simmer the soup uncovered so excess liquid evaporates.

For a medium pot of about 4 to 6 cups of soup, start small. Try about 1 tablespoon of cornstarch mixed with 1 tablespoon of cold water, 1 to 2 tablespoons of flour mixed with cold water, or about 1/4 cup of mashed potato. Let the soup cook briefly, check the consistency, and add more only if needed.

Quick-Reference Soup Thickening Guide

Why These Soup-Thickening Methods Work

Different thickeners solve different problems. Starches such as flour and cornstarch absorb liquid as they cook. Potatoes, beans and vegetables release starch or fiber when mashed or blended. Reducing simply removes excess water through evaporation.

That means there is no single soup thickener that is right for every recipe. A clear chicken soup may be better with a small cornstarch slurry, while potato soup can often be thickened simply by blending some of the potatoes already in the pot.

1. Make a Flour Slurry

A flour slurry is one of the easiest ways to fix watery soup. It works especially well for hearty chicken soups, beef soups, stews and vegetable soups where a slightly opaque broth is fine.

Start with 1 to 2 tablespoons all-purpose flour for about 4 to 6 cups of soup. In a small bowl, whisk the flour with roughly twice as much cold water until completely smooth.

Slowly stir the slurry into gently simmering soup. Cook for several minutes, stirring occasionally, so the flour can thicken the liquid and lose its raw flour taste.

Do not sprinkle dry flour directly into the soup. It tends to form stubborn lumps as soon as the outside of the flour gets wet.

2. Use a Cornstarch Slurry

A cornstarch slurry for soup is a good choice when you need a fast, powerful thickener. It works particularly well when you do not want to add much extra fat or significantly change the flavor.

For about 4 to 6 cups of soup, start with 1 tablespoon cornstarch mixed with 1 tablespoon cold water. Stir until completely smooth before adding it to the soup.

Pour the slurry into the hot soup while stirring. Give it a short time to thicken before deciding whether you need more.

Do not add several tablespoons at once. Too much cornstarch can turn a pleasant soup into a gelatinous mixture very quickly.

Allergy notice: Always check ingredient labels and avoid substitutions that may introduce allergens. This recipe has not been verified as allergen-free.

3. Make a Roux

A roux is an excellent choice when you want a rich, creamy soup with a little more body. It is especially useful for chowders, creamy chicken soup, broccoli cheese soup and similar recipes.

For a moderate amount of thickening, start with 1 to 2 tablespoons butter and an equal amount of flour.

Melt the butter in a separate small saucepan. Stir in the flour and cook for about 1 to 2 minutes, stirring constantly. Whisk in a little warm broth from the soup until the mixture is smooth, then gradually stir it back into the soup.

This extra step helps prevent flour lumps and removes the raw taste that flour can have when it has not cooked long enough.

4. Blend Part of the Soup

If your soup already contains beans, lentils, potatoes, squash or other soft vegetables, you may not need to add another ingredient at all.

Remove about 1 to 2 cups of the soup, blend it until mostly smooth, and stir it back into the pot. You can also use an immersion blender for a few short pulses directly in the pot.

This method is particularly useful when you want to thicken soup without flour or cornstarch.

Be careful with potato-heavy soups. Blending potatoes too aggressively can break down their starches and create a gummy, glue-like texture. Use short pulses and stop as soon as the soup has enough body.

5. Add Mashed Potatoes or Potato Flakes

Potatoes are an easy soup thickener for chowders, vegetable soups and other hearty recipes.

Start with about 1/4 cup plain mashed potato for 4 to 6 cups of soup. Stir it in thoroughly, simmer briefly, and check the consistency.

Instant potato flakes work too. Start with only 1 to 2 tablespoons, stir well, and wait before adding more. Potato flakes absorb liquid quickly, so a small amount can make a noticeable difference.

Plain potatoes work best. Strongly seasoned leftover mashed potatoes can change the salt level and flavor of your soup.

6. Add Cream or Other Dairy

If you are trying to thicken creamy soup, heavy cream, half-and-half, evaporated milk, sour cream or full-fat plain yogurt can add richness and body.

For 4 to 6 cups of soup, try starting with about 1/4 to 1/2 cup of heavy cream or half-and-half. Keep in mind that dairy alone usually makes soup richer and somewhat thicker rather than dramatically thickening it.

For a very thin creamy soup, combine dairy with another technique such as a roux, blended vegetables or reduction.

Once dairy is added, avoid aggressively boiling the soup. Gentle heat helps maintain a smooth texture, especially with lower-fat dairy or cultured ingredients such as yogurt and sour cream.

7. Simmer the Soup Uncovered

Sometimes the easiest answer to how to fix watery soup is simply to remove some of the excess water.

Take off the lid and let the soup simmer gently for about 10 to 20 minutes, stirring occasionally. As water evaporates, the soup becomes thicker and its flavors become more concentrated.

This method is particularly useful when the soup tastes good but simply has too much broth.

Watch the seasoning. Because reducing concentrates everything in the pot, an already salty soup can become too salty if you reduce it significantly.

Which Thickening Method Should You Use?

For brothy chicken or vegetable soup, try reduction first if you simply added too much liquid. A small cornstarch slurry works when you need a quicker fix.

For creamy soups and chowders, a roux usually gives the most traditional smooth, substantial texture. Cream can add richness afterward.

For potato soup, mash some potatoes against the side of the pot or briefly blend part of the soup. Potato flakes are a useful backup when you need more body quickly.

For bean, lentil and vegetable soups, blending part of the soup is often the simplest option because the ingredients already in the pot become the thickener.

For soups you want to thicken without flour, choose cornstarch, potatoes, blended beans or vegetables, dairy when appropriate, or uncovered reduction.

Tips for Thickening Soup Successfully

• Start with less thickener than you think you need.
• Give starches time to work before adding another batch.
• Always mix flour or cornstarch with cool liquid before adding it to hot soup.
• Stir while adding a slurry so it disperses evenly.
• Remember that many soups become thicker as they cool.
• Taste again after reducing because the salt and seasonings become more concentrated.

How This Comes Together

First decide whether your soup actually needs a thickening ingredient. If it is simply too watery because you added too much stock, simmering uncovered may solve the problem.

If you need a bigger change, choose a thickener that suits the soup. Add a small amount, cook or simmer as required, and then check the consistency before repeating.

The key is working in stages. Thickening gradually gives you much more control over the final texture.

How to Fix Soup That Is Too Thick

If you went a little too far with the thickener, the easiest solution is usually to add liquid back gradually.

Add a few tablespoons of broth, stock, water, milk or cream at a time, depending on the type of soup. Stir thoroughly and let the soup warm through before checking the consistency again.

Use broth for savory soups when you do not want to dilute the flavor too much. Milk or cream works well for creamy soups. Water is fine in a pinch, but taste the soup afterward because you may need to adjust the seasoning.

If a starch-thickened soup becomes much thicker after sitting or refrigerating, do not immediately add a large amount of liquid. Warm it first, then thin it gradually until it reaches the consistency you want.

Common Mistakes When Thickening Soup

Adding Dry Flour Directly to the Pot

Dry flour can form lumps almost immediately in hot liquid. Whisk it with cold water first or cook it with fat to make a roux.

Using Too Much Cornstarch

Cornstarch is powerful. Start with a small slurry, let it work, and then decide whether the soup needs more.

Adding Too Much Thickener at Once

Whether you use flour, cornstarch, potato flakes or another thickener, gradual additions give you better control.

Boiling Dairy Aggressively

After adding cream, milk, sour cream or yogurt, use gentler heat. Aggressive boiling can hurt the smooth texture of dairy-based soups.

Over-Blending Potatoes

A blender can turn cooked potatoes gummy when they are processed too much. Blend briefly or mash them by hand when possible.

Not Waiting Before Adding More

Give your thickener time to work. Adding a second batch immediately can leave you with soup that becomes much thicker than expected a few minutes later.

Storage and Reheating

Store leftover soup in covered containers in the refrigerator. Most cooked leftovers should be used within 3 to 4 days.

Starch-thickened soups often become thicker in the refrigerator. When reheating, stir in a splash of broth, water or milk if necessary to restore the original consistency.

Reheat leftovers thoroughly. USDA guidance recommends reheating leftovers to 165°F throughout.

Food Safety Note

Perishable soup should not sit at room temperature for extended periods. Refrigerate leftovers promptly in shallow containers so they cool efficiently. If soup has been left unrefrigerated for more than 2 hours, or more than 1 hour when temperatures are above 90°F, follow current food-safety guidance rather than relying on reheating to make improperly stored food safe.

Frequently Asked Questions

What is the best way to thicken soup?

The best method depends on the soup. Cornstarch is useful for quick thickening, a roux works well for creamy soups and chowders, and blending part of the soup is excellent for bean, lentil, potato and vegetable soups. If the soup simply contains too much liquid, simmering it uncovered may be all you need.

Can I thicken soup without flour?

Yes. Cornstarch, mashed potatoes, potato flakes, blended beans or vegetables, dairy, and uncovered reduction can all thicken soup without flour.

Can I thicken soup after it is cooked?

Yes. Most of these methods work on an already-cooked soup. A slurry, potato flakes, partial blending or additional uncovered simmering can be particularly convenient for fixing soup just before serving.

How do I thicken creamy soup?

For creamy soup, try a roux, blended vegetables or potatoes, or a small amount of flour or cornstarch slurry. Heavy cream adds richness and some body, but a very watery creamy soup usually needs another thickening method as well.

Why is my soup still watery?

Your soup may contain too much broth, the vegetables may have released additional water, or you may not have used enough thickener. Starch thickeners also need enough heat and time to work. Give the soup a few minutes before deciding it needs another addition.

Final Notes

A thin soup is usually fixable, so do not rush to add a large amount of thickener. First consider what kind of soup you are making, then choose the method that fits its texture and flavor.

Useful cooking tip: Before reaching for flour or cornstarch, scoop out a spoonful of soup and let it cool slightly. Soup often feels noticeably thicker once it is no longer piping hot, and checking first can keep you from accidentally over-thickening the whole pot.

Trusted Resources

For current guidance on safely cooling, storing and reheating cooked foods, consult the USDA Food Safety and Inspection Service.

Mistakenly Delicious Kitchen Picks

Helpful Kitchen Tools for Easier Cooking

These beginner-friendly guides and kitchen picks can make cooking, baking, food-safety checks, and meal prep easier.

Affiliate disclosure: This section contains Amazon affiliate links. As an Amazon Associate, I earn from qualifying purchases at no additional cost to you.

Essential Kitchen Tools for Beginner Cooks

Start with practical everyday tools instead of filling your kitchen with gadgets you may rarely use.

Read Guide View on Amazon

Best Affordable Meat Thermometers

Check chicken, burgers, roasts, and other foods without guessing whether the center is fully cooked.

Read Guide View on Amazon

Best Baking Dishes for Casseroles

Compare dependable baking dishes for casseroles, rice bakes, biscuit bakes, desserts, and family meals.

Read Guide View on Amazon

Best Air Fryers for Beginner Cooks

Find a beginner-friendly air fryer for crispy foods, quick dinners, reheating leftovers, and smaller meals.

Read Guide View on Amazon

Best Food Storage Containers for Meal Prep

Store leftovers, lunches, freezer meals, and weekly meal-prep portions more neatly.

Read Guide View on Amazon

Featured Kitchen Pick

Explore another practical kitchen pick that can make everyday cooking and food preparation easier.

View on Amazon

• Best Ingredient Swaps for Beginner Cooks
• Simple Pantry Soup
• Easy Vegetable Soup for Beginners
• Loaded Baked Potato Soup
• Creamy Cheeseburger Soup