How Do You Thicken Homemade Tomato Sauce?

By: Sara Elliott  | 
close up of tomato and vegetables sauce in a pan on the kitchen
The consistency is really a matter of taste. Os Tartarouchos/Getty Images

Homemade tomato sauce is the secret indulgence of many backyard vegetable gardeners. It takes quite a few tomatoes to make a savory sauce (about 5 pounds or 2.2 kilograms for every 6 cups), but the vivid fresh flavor is worth it. Tomato sauce can be the base for lots of autumn and winter comfort foods like stew, minestrone soup and chili, and the bright, garden goodness of homemade sauce will enhance almost any tomato-based recipe.

If you've carefully blended your tomato sauce to a smooth consistency only to discover that the end result isn't as thick and rich as you'd like, there are still some things you can do to save the day. Thin sauce isn't a disaster, it's an opportunity.


To Thicken or Not to Thicken

Is your sauce closer to tomato soup?

Here are some ways to deal with thin sauce:

Leave it on the back burner. Most tomato purists advocate giving a watery sauce a little more time on the stove (sans pot lid, of course). Letting tomato sauce thicken by evaporating the excess liquid has some added advantages. The longer tomato sauce cooks, the more complex, smooth and flavorful it becomes. If your sauces have tasted brassy or almost metallic in the past, another hour on the stove could make this year's batch thick enough to coat the back of your ladle and give it some deep flavor notes you'll love. Why not finish it off in a low oven? You won't have to worry about burning the bottom of the pot, and you can spend the next hour doing something more entertaining than watching molten tomatoes bubbling. You can always employ your trusty crock pot, too.


Add a thickener. Artificial thickeners and tomatoes are often at odds with one another. Starches don't hold up well to the acid in tomatoes. Cornstarch, potato starch and some flours can alter the flavor of tomato-based sauces, create lumps or break down over time. If you do add flour, arrowroot or cornstarch, mix it into a little cold water first, and use the tomato sauce right away.

Don't do anything. Thin isn't necessarily bad, and if you plan on using your homemade sauce in stew, soup or chili, the other ingredients will thicken the sauce for you. Lightly mashed potatoes in a stew or mashed beans in chili will add body to your sauce and blend perfectly with the other flavors in the recipe.


Look to Your Pantry

Here are some additions that will thicken your tomato sauce:

  • Add oil. A little olive oil and a hit with an immersion style blender will help emulsify the sauce (incorporate the oil and other ingredients), thickening it naturally. The addition of some oil will help create a smoother texture, too.
  • Add other vegetables. No one ever said that tomato sauce could only contain one vegetable. Blending in some ground carrots or caramelized onion will turn your one-note sauce into a symphony of flavor and thicken it in the process.
  • Pour on the paste. It may seem like a bit of a cheat, but adding some prepared tomato paste to your thin homemade sauce may be the easiest way to give it a thicker consistency. Don't worry; the sauce will still definitely retain its garden-fresh appeal. Just think of adding tomato paste as including a little more of a good thing.

Once your homemade, garden-fresh tomato sauce is cooked to perfection, try using it in a family-friendly meal like meatloaf or chili, or just serve it over spaghetti.


Thicken Tomato Sauce FAQ

How do you make tomato sauce thicker?
The easiest way to thicken tomato sauce is to let it cook down on low heat on the stove in a lidless stock pot until you've got the consistency you want. As a bonus, the longer it cooks, the more complex, smooth, and flavorful it becomes.
How do you reduce liquid in a slow cooker?
Regardless of whether you've got just a liquid or a full meal in the slow cooker, you can reduce it by removing the lid and turning up the heat for the last 30 to 60 minutes of cooking. If you're remaking a dish that turned out a little too thin last time, prop the lid open slightly for the entire duration of cooking, accounting for an increased cook time by adding a few extra minutes.
What are the main methods of thickening sauces?
You can either cook a sauce on low heat for longer to reduce the liquid or add a thickening agent. Cornstarch, potato starch, and some flours can be made into a slurry and used to thicken sauces, but unfortunately these don't work with tomato sauces, as starches don't hold up well to the acid in tomatoes.
How do you thicken pasta sauce quickly?
In a pinch, you can add a can of tomato paste to your tomato sauce to thicken it. It's a bit of a cheat, but it does the trick and doesn't change the overall flavor very much.
What can I do if my soup is too watery?
If it's simply got too much broth in it, consider just scooping some out, putting it in a container or jar, and storing it in the fridge or freezer for another dish. If you're dealing with a blended soup, like tomato soup, then simply turn down the heat on the stove to low, remove the pot lid, and let the soup cook down for an hour or so. Some of the liquid will evaporate, leaving you with a thicker soup.

Lots More Information

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