Pasta and sauce in a bowl

How to Make Tomato Pasta Sauce Less Watery

We can all agree that nothing beats a thick hearty tomato sauce for our pasta dishes. It goes so well with any pasta like, spaghetti, linguine, ravioli, and the list goes on.

That’s everyone’s goal but a common question heard around the world in kitchens is why isn’t my spaghetti sauce thick?

There are several reasons why you might wind up with a watery pasta sauce. Even if you follow the directions precisely, there are a few things that may go wrong.

The amount of moisture in the veggies you choose. When vegetables are cooked down, they release liquid. Some vegetables have more than others, leaving you with extra unaccounted moisture.

You didn’t let your pasta sauce simmer and thicken long enough on the stove. If we’re in a hurry, sometimes we don’t allow our pasta sauce to simmer down enough. It’s so easy to not account for enough time when cooking tomato sauce.

Too many liquid-based ingredients were used. We overuse oil, broth, cream, and water when we wing a pasta sauce, leaving us with a watery sauce.

How to Thicken Pasta Sauce

Here are three simple and quick ways to thicken a sauce that’s too watery.

Make a Roux

Making a fast roux is an easy method to thicken any sauce. Whether you’re preparing a cheese sauce or just thickening a pasta sauce, making a quick roux is simple. The ratio of flour to fat used in a roux is generally 1:1. We utilize all-purpose flour and unsalted butter. When making a richer pasta sauce, we prefer to use a roux.

In a real pinch you can forgo the butter and just use flour to thicken the sauce. A good general ratio to use is 2 tablespoons flour for each cup of liquid. Start by adding a little bit at a time and cooking, stirring, for a few minutes to allow the sauce enough time to thicken and cook off the raw flour flavor; if the results are insufficient, add more.

How to Make a Roux

  1. To create a roux, heat a separate saucepan (that is not your pasta sauce pan) over medium heat.
  2. Add the butter to the saucepan and, when melted, whisk in the flour. Keep an eye on the butter to avoid burning.
  3. Allow the flour and butter to cook for 1-2 minutes, until a paste forms.
  4. Bring the simmering sauce to a gentle boil. Whisk in the roux and cook for another 30 seconds to 1 minute, or until smooth and thickened.

Use Pasta Water

Yes, you can thicken tomato sauce by adding pasta water. When it comes to pasta sauce, starchy pasta water is like magic because you don’t have to do much, it’s already there for you! Just remember that you need to set aside some pasta water before straining the pasta. Check out this article If you don’t have a strainer or colander.

How to Use Starchy Pasta Water

  1. Bring a large pot of salted water to a boil. Add the pasta and cook until al dente, according to package directions.
  2. When it comes to straining the pasta, drain one cup of starchy cooking water first. In case we have more need than planned, we like to keep this reserved pasta water!
  3. Add 1/4 cup of the pasta water to your pasta sauce and bring the pasta sauce to a gentle boil. Your pasta sauce should thicken as it simmers. You may need to add more in but don’t go overboard with adding too much.

Use Cornstarch

Cornstarch slurry is another quick and simple approach to thicken your sauce. When preparing a slurry, use a 2:1 ratio (water:cornstarch). When the cornstarch is cooked, it becomes activated.

We like to use a cornstarch slurry in pasta sauces with strong tastes, such as Asian-inspired pasta dishes, tomato sauces, and so on. Why? Because if you’re making a simple pasta sauce, the cornstarch taste may be rather overwhelming.

We like to make a slurry rather than simply adding cornstarch to a pasta sauce because we don’t want clumps of cornstarch in our final product.

How to Make a Cornstarch Slurry

  1. Add water and cornstarch to a small bowl and whisk the two ingredients together until the cornstarch has dissolved. Use a small amount of cornstarch, we recommend 1 tbsp with about a cup of water.
  2. Bring a moderate boil to the sauce and whisk in the cornstarch mix. As it simmers, your pasta sauce should thicken rapidly.


We hope this has helped you understand how to thicken pasta sauce! If your pasta sauce is still too watery, don’t hesitate to try one of these methods.

Buon appetito!