How to Thicken Spaghetti Sauce

Co-authored by Katie Hake RDN, LD

You may need to thicken your spaghetti sauce at some point, whether you make it from scratch or buy it in a jar from the grocery store. There are many ways to thicken a sauce, but some can slightly change the taste or texture. The ingredients you have on hand, the amount of time you have available and the taste you are trying to achieve will determine which of the thickening options you choose. The following guide will help you thicken your spaghetti sauce.

Method 1

Method 1 of 2:

Thickening Without Changing the Flavor

1
Reduce by cooking at a low boil or simmer. Reduction is the most natural and easy way to thicken a spaghetti sauce. Here's how you do it:
- Bring your tomato sauce to a boil and slightly reduce the heat, allowing it to simmer uncovered to the desired consistency. Stir the sauce often to prevent burning. This will encourage the evaporation of extra water, thickening the sauce.
- This method does not change the taste of the sauce, but can take more time, depending on how much water you want to evaporate.
2
Add some cornstarch to the spaghetti sauce. The cornstarch mixture has no flavor, so it will not change the taste, but it may change the consistency of the sauce by giving it a silky sheen.
- Use equal parts water and cornstarch, mix, then add it to the sauce. Only pour in a small amount at first. Cornstarch is a powerful thickening agent, so you might need less than a teaspoon for a large pot of spaghetti sauce.
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3
Make a Roux and add it to the sauce. Melting butter and adding flour makes a roux, and this is the most common way to thicken a sauce. They are used in French cooking as a thickening agent. In fact, a roux is the reason that the creamy alfredo sauce is as thick as it is!
- After making the roux and adding bit by bit to the spaghetti sauce, you should cook the sauce for at least 30 minutes longer or you will be able to taste the grainy flour texture. You can also cook the roux before adding to the spaghetti, thus removing the mealy flour texture.
- Even with the additional cooking, the roux can change the flavor of your sauce, albeit subtly.
4
Try adding breadcrumbs. Breadcrumbs, like roux, is a nice thickening agent because it's primarily flour. Although you may be able to taste the addition of breadcrumbs slightly, they are pretty much vectors for the sauce; you'll definitely notice the thickness more than you'll notice the flavor.
5
Add mashed potatoes. Peel, boil, and mash potatoes, adding butter and milk or cream if desired, and stir them into the sauce. The flavour may become very slightly sweeter, but the main effect is the thicker sauce. It will also be much more filling.
6
Finish cooking the spaghetti in the sauce itself. Prepare the spaghetti until it's slightly underdone (south still of al-dente). Drain the spaghetti thoroughly so that no water remains and add the spaghetti into the pan with the sauce. Finish cooking the spaghetti one or two minutes in the sauce itself. The starch from the spaghetti will help thicken the sauce, and you'll be sure that the spaghetti is well-coated with sauce.

Method 2

Method 2 of 2:

Thickening with Flavor Boosters

1
Add tomato paste. The best time to add the paste is in the beginning, allowing the flavors of the spices to mellow the paste flavor. Tomato paste can also be added later if you need a quick thickening agent.
2
Add grated Parmesan or Romano cheese to thicken the sauce. Grated or shredded cheese will help to thicken the sauce quickly. The cheese will slightly change the taste of the sauce.
- Cheeses such as Parmesan and Romano have a higher salt taste, so keep that in mind when adding salt to your sauce.
3
Add heavy cream to make a creamy tomato sauce. This will slightly thicken the sauce and completely changes the taste and type of spaghetti sauce.
4
Add vegetables to your sauce. Vegetables add depth and richness to your spaghetti sauce, giving it additional nutrition to boot.
- Traditional Italian cooks have been known to add shredded carrots to sauce, but it must be allowed to cook until the carrots are soft and mushy. This also helps reduce the acidity of the sauce.
- You can puree and sauté onions and peppers to thicken the sauce, but this will change the flavor.
- Try also shredding up various mushrooms into small pieces and adding them for extra thickness and a delicious umami flavor.
- Finely shredded eggplant also works like a charm! Be sure to remove the tough outer skin before shredding.
5
Brown some ground beef or Italian sausage and add it to the sauce. The meat and tomato flavors are blended best when allowed to cook in the spaghetti sauce for a longer period.

Community Q&A

Question

What do I do if I put too much hot sauce in my spaghetti sauce?

Kristi Lee

Community Answer

If you added too much hot sauce to your spaghetti sauce, you can add salt. It takes away from the burn.
Question

Can I use mashed potato flakes?

Community Answer

You could try but I don't think it would help very much as they have a low starch content. It might just result in a bad texture for your sauce.
Question

How do I make my sauce taste beefier without using meat?

Community Answer

Add some beef stock or broth when cooking the sauce for a more robust flavor.

Warnings

Ensure you mix the cornstarch with cold water to avoid lumps.

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Adding water from cooked pasta does not thicken the sauce.

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