Just hear us out.
Each product we feature has been independently selected and reviewed by our editorial team. If you make a purchase using the links included, we may earn commission.

Most tomato and marinara sauces are just fine when you follow the recipe precisely and use fresh ingredients. These universal sauces are usually robust, with hints of tomato sweetness and a delicate herbaceousness from loads of basil, oregano, and parsley. But every once in a while, a batch of homemade tomato sauce, or even a beloved jarred marinara sauce, just falls flat. You know it the moment a drop hits your tongue—limp, lifeless, and just plain puny. It’s no fault of your own or the ingredients. Sometimes, everything just doesn’t come together like you intended. (There’s a life lesson here, too, dear reader.)

The good news is you can resurrect that sauce before you settle for mediocre. But the ingredient you need to save that stock pot of sauce is likely to cause some turned-up noses.

Fish sauce will save your tomato sauce.

Why fish sauce? Well, this bottle of slap-you-in-the-face funk liquid adds a certain je ne sais quoi to any dish in which it’s used, from marinades for steak tacos to even guacamole. It’s deeply rich and intense, and there’s almost nothing else like it in the grocery store.

In tomato sauce, fish sauce is particularly powerful because it adds a boastful meaty flavor to a sauce when nary a speck of meat is to be found. Of course, if you’re cooking this sauce for a vegetarian or vegan, you need to tell them you’ve used fish sauce. The secret ingredient may make this dish a no-go for them.

So what is fish sauce?

Once you catch the tiniest whiff of fish sauce, you may believe it’s made during some ungodly procedure—no really, be sure to put the cap back on or else—but it’s actually quite simple: salt a bunch of fish (usually anchovies), let them ferment for months (even years), then squish them. The brown liquid that oozes out is fish sauce.

Please, don’t DIY this at home unless you want to make everyone in your house and your neighborhood quite angry.

Fish sauce is rich in glutamates, acids that read as umami to your tongue. So when fish sauce is used in any dish, you’re adding the same deeply rich, unctuous flavor you know and love in miso, seared beef, even aged cheeses. But in fish sauce, it’s amplified by several factors.

If you don’t want to use fish sauce, you can use aged Parmesan cheese as a flavor booster. It’s not as strong, but it’ll work. Canned or jarred anchovies will work, too. Just let them melt into your pan as you cook down any onions and garlic. Both of these packs a powerful umami punch, but even they can’t beat back the funk of fish sauce.

Be sure to add it at the right time

There’s just one thing you need to know about fish sauce before you use it. You need to let it cook before you eat the dish. If you splash fish sauce into marinara sauce or soup just before serving, you’re going to be hit with full-on fish funk at your first bite.

Instead, pour in a bit of fish sauce, a teaspoon at a time, and cook 10-15 minutes. The flavors will meld into the recipe and disappear. What’s left is booming flavor, sans fishiness.

Can’t detect a difference? Keep adding the brown liquid, bit by bit, to get what you want. But you won’t need a lot. For tomato sauce, one tablespoon of fish sauce is usually adequate for a two-quart recipe.

Look for fish sauces that aren’t doctored up with unnecessary ingredients to mask off flavors or odors. Fish sauces that aren’t high quality can use sugar or spices to flavor the sauce. Red Boat, our pick, has just two ingredients: anchovies and salt.

Once you see how good it is in your tomato sauce, you may be tempted to add fish sauce to every dish. Try recipes like Umami Bomb Burgers and Spaghetti Aglio e Olio, both of which are designed to really let fish sauce shine.