14 Ways to Thicken Tomato Sauce

Making a homemade tomato sauce is super simple, but what can you do if it isn’t quite thick enough? Here are 14 ways to easily thicken tomato sauce.

We love pasta dishes in our home for so many reasons.

Red sauces are easy and cost effective, especially when poured over a bowl of perfectly al dente pasta.

I make a great Italian red meat sauce that is always a crowd please and turns out beautifully every time.

Occasionally, I will need to thicken it for my homemade no-boil lasagna and I’m sharing a few easy ways you can thicken your tomato sauce.

If you prefer a different type of pasta sauce, be sure to check out my creamy white sauce, lemon garlic pasta, or the family favorite creamy pesto pasta.

Why Do You Need To Thicken Tomato Sauce?

If you are making homemade tomato sauce from garden fresh tomatoes, you may be frustrated to find that you are consistently left with a watery sauce.

Premade, canned tomato sauces are thick, thanks to emulsifiers.

A watery sauce pools around the bottom of the bowl of pasta, more like a soup than a sauce. It doesn’t cling to pasta, meats, or vegetables, and so it doesn’t add any flavor to the dish.

What Causes Watery Tomato Sauce?

Enzymes! Fresh tomatoes are filled with enzymes that break down and eat through thickening agents. You need to deactivate those enzymes before you do anything else.

Otherwise, no matter what thickening method you try, you’ll be fighting against the very tomatoes themselves!

So before you go any further, bring your tomatoes up to a rapid boil – stirring constantly to prevent burning – and then bring the sauce back down to a simmer. That burst of high heat will deactivate the enzymes that would work against you.

Common Foods That Require A Thick Sauce

There are times when you can get by with a thin sauce, but most of the time, you need a sauce with some grip.

• Spaghetti – Spaghetti sauce doesn’t need to be fancy, but it does need to stay on the noodles!
• Bolognese – This meaty sauce is meant to be stick-to-your-ribs thick.
• Pizza Sauce – You’ll have a hard time keeping your toppings on your pizza slice if the sauce is watery!

1. Let The Sauce Reduce

If you look at tomato sauce recipes from generations past, you’ll notice that they let the sauce simmer for a long time – actually, hours.

The easiest way to get rid of the excess water in your thin sauce is to simply heat it high enough and long enough that it evaporates off!

This simple trick will give you a thick tomato sauce without adding any additional flavors. In fact, it will naturally amplify the tomato flavor, and any other herbs and spices you added. An extended period of simmering will also significantly reduce the acidity of the sauce.

All you need is time! You can let a crockpot handle this for you, if you’d like. If you want to let the sauce simmer on the stovetop, be sure to use a wide, shallow pan.

This increases the amount of surface area where water can evaporate.

2. Add A Starch

A starch is a long chain of polymers. A starch can thicken watery sauces because each molecule in that chain will absorb water, if combined with heat!

There are different ways to add starches to a sauce. Adding any of these starches will significantly shorten the amount of time spent during the reduction process!

• Make A Cornstarch Slurry – Perhaps the best thickening agent is corn starch. In a small bowl, mix together equal parts cold water and corn starch. Once the cornstarch is completely dissolved, add it to your watery pasta sauce. If you want to avoid corn starch, you can substitute arrowroot powder.
• Add Mashed Potatoes – Potato starch is a powerful starch, and it only takes a little bit. It’s also a great starch option for those with a gluten allergy! If you don’t have any leftover mashed potatoes on hand, you can achieve the same result with about half cup of instant potato flakes.
• Make A Roux – A roux is a mixture of butter (or another oil) and flour. Melt a quarter cup of butter on the stovetop over medium heat. Add an equal amount of all purpose flour and mix until it’s nice and smooth. Add it to your red sauce.

3. Add Fine Breadcrumbs

Breadcrumbs are another starch option that you can use in a pinch. Stale bread is best, and if you can, toast the bread before breaking it down into fine crumbs.

These crumbs will soak up additional water, acting somewhat like a natural sponge. A half cup of bread crumbs will thicken a cup of sauce. Be sure to stir the sauce vigorously when you add the breadcrumbs, as they can have a tendency to become lumpy otherwise.

The yeast in the bread might add a slightly sour taste to the sauce.

4. Add Shredded Parmesan Cheese

This is a delicious way to improve both the texture and the flavor of your sauce! Adding cheese to your sauce will not only make it thicker, but also make it creamier.

It may take a while for the cheese to fully melt into the sauce, so add it as early in the cooking process as possible.

The cheese won’t absorb any of the excess liquid, but it will add a thickness of its own.

5. Stir In A Can Of Tomato Paste

Perhaps the best method of thickening a watery spaghetti sauce is to add a can of tomato paste. Tomato paste won’t alter the taste of the sauce at all, and will even boost the tomato flavor!

Add the tomato paste to the sauce in individual spoonfuls, rather than dumping in the whole can all at once. This helps the tomato paste incorporate into the sauce better.

6. Add An Egg Yolk

Adding an egg yolk is a great way to thicken your sauce to the desired consistency! You can’t just pop the egg yolk into the sauce pan and stir, however.

Separate out a cup of tomato sauce and mix the egg into it. Once that mixture is fully blended, you can add the cup of liquid back into the pan.

7. Add Mashed Vegetables

We’ve already talked about adding mashed potatoes to help your sauce reach a thick consistency, but other mashed vegetables will do the trick as well!

However, they won’t be functioning in the same way as a starch. Instead, they will simply be adding bulk to the sauce. Some vegetables to consider are mashed cauliflower, carrots, and onions.

All of these options will affect the flavor of the sauce, so keep in mind what flavor profile you need for the recipe.

Mashed or pureed carrots will add a sweetness to the sauce that children might enjoy!

8. Combine With A Thicker Sauce

Sometimes, time is money.

If your homemade spaghetti sauce is just too thin to cut it, and you have a jar of thicker tomato sauce that you either bought at a store or canned yourself, there’s no shame in simply combining the two.

Work smarter, not harder!

9. Melt Cream Cheese In The Sauce

If you really want a creamy, thick texture, look no further than a block of cream cheese.

It can take a while for it to fully melt into the sauce, so add it early in the cooking process.

The cream cheese will turn the tomato sauce into a lighter orange color, more commonly called a “cheese sauce”, but it’s oh so delicious.

10. Clear Gel Can Thicken Thin Spaghetti Sauce

If you’re cooking up a homemade spaghetti sauce to can, consider using clear gel to thicken it to the consistency you want.

Gelatin is an easy way to thicken up sauce prior to canning, and it stays shelf-stable.

11. Use Pasta Water

When you cook pasta, the starchy ingredients from the pasta soak into the water. The simply ways are often the best ways, and it doesn’t get much more simple than adding a cup of leftover pasta water to your homemade sauce.

12. Add Meat To Create A Thick Spaghetti Sauce

Many recipes with tomato sauce also use meats. You can use those meats to help thicken your spaghetti sauce!

They won’t soak up the extra water, but they will add bulk to the sauce, which will improve the texture. You can add ground beef, Italian sausage, pork sausage, or stew meat.

13. Grind Some Almonds

Starches are one of the best ways to take care of extra liquid in a sauce, but for people with gluten allergies, options are limited.

One great way is to grind up almonds! Almond flour is a particularly thirsty flour, and will soak up a large amount of water.

Adding ground almonds to your watery sauce will work somewhat similarly to adding breadcrumbs.

14. Add A Squeeze Of Lemon

Tomatoes are full of pectin. You can use that to your advantage by adding the acid of lemon!

The lemon juice will cause the pectin to firm up, thickening the texture of the sauce. A half a lemon will be plenty for a large pan of sauce.

Keep in mind that lemon is a strong flavor. Don’t get overzealous and overdo it!