How to Thicken Soup: 10 Methods That Actually Work

“How do I make my soup thicker?” might be the most common question I receive from home cooks. A watery soup can be disappointing — you want that satisfying, spoon-coating consistency that makes you reach for another bowl. The good news? There are many ways to achieve it, and the best method depends on what kind of soup you’re making.

Understanding Why Soups Need Thickening

Before diving into techniques, let’s understand what we’re actually doing when we thicken soup. We’re either:

1. Adding starch that absorbs liquid and swells
2. Emulsifying fats into the liquid
3. Adding proteins that create structure
4. Reducing liquid through evaporation

Different methods suit different soups. A cream-based chowder calls for different treatment than a rustic bean soup.

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Method 1: The Classic Roux

A roux is equal parts fat and flour, cooked together before liquid is added. It’s the foundation of countless French soups and provides not just thickness but also a subtle nutty flavor.

How to Make It:

1. Melt 2 tablespoons butter in your soup pot
2. Whisk in 2 tablespoons all-purpose flour
3. Cook, stirring constantly, for 2-3 minutes (this cooks out the raw flour taste)
4. Slowly whisk in your liquid, then add remaining ingredients

Best for: Cream soups, chowders, velouté-style soups

Pro tip: The longer you cook a roux, the darker and more flavorful it becomes — but it also loses thickening power. A blonde roux thickens more than a dark roux.

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Method 2: Cornstarch Slurry

This is the quickest fix for soup that’s already made but too thin. Cornstarch has twice the thickening power of flour and creates a cleaner, more neutral flavor.

How to Use It:

1. Mix 1 tablespoon cornstarch with 2 tablespoons cold water (never add dry cornstarch directly to hot liquid — it will clump)
2. Stir the slurry into your simmering soup
3. Cook for 2-3 minutes until thickened
4. Repeat if needed

Best for: Clear broths, Asian-style soups, quick fixes

Important: Cornstarch-thickened soups don’t reheat as well — they can thin out or become gummy. Use this method for soups you’ll serve immediately.

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Method 3: Puree Part of the Soup

This is my favorite method for chunky vegetable soups. It’s natural, adds no extra ingredients, and creates a wonderfully rustic texture.

How to Do It:

1. Remove 2-3 cups of your soup (including vegetables) to a blender
2. Blend until smooth
3. Stir back into the pot

Alternatively, use an immersion blender directly in the pot and pulse a few times — don’t fully blend, just enough to break down some of the vegetables.

Best for: Bean soups, vegetable soups, minestrone, potato soup

Why it works: Starches from potatoes, beans, and other vegetables naturally thicken the liquid while adding body and flavor.

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Method 4: Add Starchy Vegetables

If your soup is thin but you haven’t started cooking yet, consider building thickness into the recipe itself.

Great Thickening Vegetables:

• Potatoes — Add diced potatoes; they release starch as they cook
• Sweet potatoes — Similar effect with a subtle sweetness
• Winter squash — Butternut squash practically melts into soup
• Parsnips — High in starch, adds earthy sweetness
• Carrots — Less starchy but adds body when pureed

Best for: Hearty soups where you want to avoid processed thickeners

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Method 5: Add Beans or Lentils

Legumes are natural thickeners. They absorb liquid as they cook and release starches that create a creamy consistency without any cream at all.

Options:

• White beans (cannellini, navy) — Mild flavor, disappear when blended
• Red lentils — Cook down completely and virtually dissolve
• Chickpeas — Hold their shape but their cooking liquid (aquafaba) thickens

Shortcut: Blend a can of drained white beans with a cup of your soup broth and stir it back in. The soup will be creamy and protein-rich without tasting “beany.”

Best for: Vegetarian soups, Mediterranean-style soups, adding protein and fiber

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Method 6: Heavy Cream or Coconut Milk

Sometimes you want richness along with thickness. Dairy or coconut-based fats create a luxurious, silky texture.

How to Use:

• Add cream at the end of cooking
• Simmer gently (don’t boil, or it may curdle)
• For coconut milk, full-fat versions thicken better than light

Best for: Bisques, cream of mushroom, tomato soup, Thai-inspired soups

Dairy alternatives: Coconut cream, cashew cream, oat cream all work well. For cashew cream, blend 1 cup raw cashews with 1 cup water until silky smooth.

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Method 7: Cream Cheese or Cheese

Adding cheese doesn’t just thicken — it completely transforms the character of a soup into something indulgent.

How to Use:

1. Cut cream cheese into cubes for faster melting
2. Add to warm (not boiling) soup
3. Stir until completely melted and incorporated

For harder cheeses like cheddar or parmesan, grate finely and stir in off the heat to prevent graininess.

Best for: Broccoli cheese soup, beer cheese soup, loaded potato soup

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Method 8: Egg Yolks (Liaison)

This classic French technique creates the most luxurious, silky texture possible. It requires care but delivers spectacular results.

How to Do It:

1. Beat 2 egg yolks with 1/2 cup cream
2. Slowly ladle about 1 cup of hot soup into the egg mixture while whisking constantly (this tempers the eggs)
3. Pour the mixture back into the soup, stirring constantly
4. Heat gently but never let it boil or the eggs will curdle

Best for: Elegant cream soups, avgolemono, special occasion cooking

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Method 9: Bread

Old-fashioned but effective. In Tuscan and Portuguese cuisines, day-old bread has thickened soups for centuries.

How to Use:

• Tear stale bread into chunks and simmer in the soup for 15-20 minutes
• It will break down and thicken the broth
• Alternatively, blend bread into the soup for a smoother result

Best for: Ribollita, açorda, gazpacho, rustic bread soups

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Method 10: Simply Reduce

Sometimes the answer is the simplest one: cook off excess liquid by simmering uncovered.

How to Do It:

1. Remove the lid from your pot
2. Simmer over medium-low heat
3. Stir occasionally to prevent sticking
4. The liquid will evaporate, concentrating both flavor and thickness

Best for: Any soup where you want to intensify flavor along with thickness

Time required: Reducing by half typically takes 20-30 minutes depending on surface area and heat level.

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Choosing the Right Method

If you want…	Use this method
Quick fix for watery soup	Cornstarch slurry
Rustic, chunky texture	Puree part of soup
Creamy without dairy	White beans or lentils
Rich and indulgent	Heavy cream + roux
Clean, clear broth	Egg drop or light cornstarch
Intense concentrated flavor	Reduction

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Common Mistakes When Thickening Soup

1. Adding thickeners too quickly — Always add gradually; you can add more but can’t take it away

2. Not cooking out flour taste — Raw flour tastes terrible; cook your roux or simmer for several minutes after adding

3. Boiling dairy — This causes curdling; keep heat gentle after adding cream

4. Adding cornstarch directly to hot liquid — Always make a slurry first

5. Over-thickening — Soup continues to thicken as it cools and as starches absorb liquid; stop when it’s slightly thinner than you want

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The Bottom Line

The best method for thickening soup depends on what you’re making and what you have on hand. For everyday cooking, I reach for the immersion blender most often — it’s fast, adds no extra ingredients, and creates great texture.

For special occasions, nothing beats a proper roux or liaison for that restaurant-quality silkiness.

Start with the least amount of thickener you think you need, then build from there. A slightly too-thin soup can be fixed; an over-thickened paste is much harder to rescue. Trust the process, taste as you go, and you’ll develop an instinct for exactly how much thickening your soups need.