The Easiest, Fastest Ways to Fix Watery Soup—No Flour or Cornstarch Required

Soups are synonymous with cold weather—nothing makes winter go from dreary to cozy faster than settling in with a big, steaming bowl. One of the best things about soup is its versatility: It can be made entirely from pantry ingredients on a weeknight, yet it also opens the door to endless creative flavors. A soup can be as simple as a chickpea soup made with just a handful of ingredients or as layered and aromatic as Moroccan harira.

But during these colder months, when soup is a staple, it helps to understand how to troubleshoot one of the biggest pitfalls: a broth that turns out thin, watery, or lacking the body you hoped for.

Why Flour and Cornstarch Don't Always Work

While plenty of soups intentionally use flour as a thickener—think creamy mushroom soup and some chowders—it's not always the best fix for lighter, brothier soups where you want just a bit of viscosity without heaviness. In those cases, flour tends to thicken too efficiently.

Flour thickens by forming a network of gelatinized starch granules, which produces a smooth, opaque consistency. That can be exactly what you want in a cream soup, but in brothy soups, it often pushes the texture in the wrong direction, creating something closer to a sauce than a spoonable broth. Flour is typically added to soup in the form of a roux, where it's cooked with fat first to remove the raw taste, but even a well-made flour-based roux can give a soup a faintly pasty or chalky quality, which is one reason our culinary director emeritus, Kenji, avoids it in both his New England clam chowder and his broccoli cheddar soup.

Timing only complicates things further—especially when you don't realize a soup is too thin until it's nearly finished. Say you taste the pot toward the end of cooking and find that the broth still lacks body. At that point, making a proper roux isn't practical, so flour often gets added directly to the soup in an attempt of a quick fix. But if you add flour directly to hot soup, it clumps on contact, forming little dumpling-like lumps before it has a chance to disperse. The workaround is to whisk flour into a cold liquid first to make a slurry, but even then it needs several minutes of active simmering. When flour is added late in the process, you're left with two bad options: Tolerate a subtle pastiness, or keep simmering longer than you'd like, risking overcooked vegetables, bloated pasta, or limp greens.

Cornstarch and other powdered starches like potato or rice flour aren't foolproof either. They can make the broth feel slightly gloopy, which is often not the intended result.

7 Ways to Thicken Soup

The good news is that you don't need flour or cornstarch to rescue a watery soup. With the right technique—and whatever pantry staples you have on hand—you can build body and richness in a way that suits your recipe, timing, and desired texture. Here are seven easy options.

Blend a Portion of the Soup

This is one of the easiest and most reliable ways to turn a thin broth into one that's full and comforting. Ladle out a portion of the soup—broth, vegetables, beans, all of it—blend it until smooth, then stir it back into the pot. The tradeoff is that it requires pulling out a blender (and washing it later), but the payoff is significant. It adds body without changing the flavor or requiring extra ingredients or a significant amount of time. In pasta e ceci, for example, blending a small portion of the chickpeas with broth creates a creamy, stew-like base that makes the whole pot feel richer and heartier.

Add Rice or Pasta

Rice and pasta both release starch as they cook, giving thin broth a naturally fuller, silkier consistency. You can stir in cooked rice or cooked pasta near the end—they soften slightly and add instant body—or add them uncooked earlier and let them cook in the soup. The main tradeoff is that this method commits you to rice or pasta becoming a noticeable part of the final dish. When it works, though, it's extremely effective: Soups like avgolemono and chicken-and-rice turn velvety as the rice swells, and pasta e fagioli relies on the starch released as the noodles finish in the pot. Even simple chicken noodle soup takes on a richer feel over time as the pasta simmers and thickens the broth.

Add Bread

Torn bread is one of the most effective ways to give a thin soup instant body. For example, in ribollita, the beloved Tuscan bread soup, bread is folded into a pot of beans and vegetables until it breaks down and thickens the entire pot. Fresh or stale bread pieces break down as they simmer, thickening the broth without making it heavy. This works best with rustic loaves—think country bread, sourdough, or anything with a sturdy crumb that can absorb liquid without turning gluey. The tradeoff is that this method requires having the right kind of bread on hand and committing to bread as a defining, carb-forward element of the finished soup, whether or not that was part of the original plan.

Add Grains or Legumes

Legumes (beans, chickpeas, lentils) and whole grains (bulgur, farro, quinoa, freekeh) also lend natural thickness to soup. As they cook, they release starch and fibers that blend into the broth. You can mash a spoonful of beans directly against the side of the pot for a quick thickening boost, or blend a small portion with broth for a creamier effect. Like the bread-thickening method above, the tradeoffs here are that you need to have these ingredients on hand, and once added, they become a substantial, defining part of the soup. This method works well in dishes like the aforementioned pasta e fagioli, where puréed beans create a velvety base, or chorba frik, which gets its body from simmered cracked green wheat. Sopa de maní, a beloved Bolivian peanut soup, becomes rich and substantial thanks in part to quinoa cooked down into the broth near the end of cooking.

Use an Egg Yolk Liaison

Whisking egg yolks with a little hot broth, then stirring the mixture back into the pot, gives soup a silky, slightly thickened texture without making it heavy. This technique works best when the soup is hot but not boiling, so the yolks can emulsify smoothly instead of scrambling. Greek avgolemono already relies on this method, using eggs to create its signature velvety finish.

Add Coconut Milk or Cream

Both coconut milk and coconut cream add richness, giving thin soups a fuller, rounder texture without the need for flour or starch. They don't thicken as dramatically as blended vegetables or beans, but they add enough body to make the broth feel more cohesive. This works best in soups that already welcome coconut's flavor. In tom kha gai, for example, coconut milk enriches the broth and helps carry the aromatics—galangal, lemongrass, makrut lime—while giving the soup its signature creamy, lightly thickened finish.

Add Ground Nuts or Seeds

Finely ground nuts and seeds blend beautifully into soup, adding nutty richness and a thicker, more cohesive texture. Almonds, cashews, walnuts, and even pumpkin or sunflower seeds emulsify easily when blended with hot broth, giving thin soups gentle body without weighing them down. You can use raw nuts or opt for toasted for an even deeper flavor. Of course, nuts and seeds noticeably influence flavor and require blending to incorporate, making this less of a neutral fix and more of a deliberate stylistic choice.

The Takeaway

No matter which method you use, the goal is a soup that's full-bodied, balanced, and satisfying. With a few pantry staples and a bit of technique, even the thinnest broth can turn into something cozy enough to carry you through the coldest months. Consider this your soup-season toolkit—one you'll reach for again and again.