What Is Fish Sauce? Everything You Need to Know

If you've ever cooked Thai food, chances are you've come across fish sauce.

It's one of the most essential ingredients in Southeast Asian cooking, yet it's also one of the most misunderstood. Some people worry it'll make their food taste fishy. Others skip it entirely because of its bold aroma.

Here's the secret: fish sauce doesn't make food taste like fish. It makes food taste more like itself.

Rich in natural umami, fish sauce adds depth, balance, and complexity to everything from stir-fries and marinades to soups and salad dressings.

What Is Fish Sauce?

Fish sauce is a savory condiment made by fermenting fish. Most commonly anchovies with salt over many months. During fermentation, the fish naturally breaks down, creating a clear amber liquid that's rich in amino acids and packed with umami.

The result is a deeply flavorful seasoning that has been a staple in Southeast Asian kitchens for centuries.

What Does Fish Sauce Taste Like?

On its own, fish sauce is intensely salty and savory with a distinctive aroma.

But once it's added to food, something remarkable happens.

Instead of tasting fishy, it enhances the flavors already in the dish. It deepens broths, brightens stir-fries, rounds out sauces, and adds a richness that's difficult to achieve with salt alone.

Think of it the way you might think about Parmesan cheese, anchovies in Caesar dressing, or soy sauce, a small amount transforms the entire dish.

Is Fish Sauce Really Made From Fish?

Yes. Traditional fish sauce contains just two ingredients:

• Fish (typically anchovies)

• Salt

Some modern brands may include sugar or preservatives, but high-quality fish sauce is often beautifully simple.

How Is Fish Sauce Used?

A little goes a long way.

Fish sauce is commonly used to:

• Season stir-fries

• Build soups and broths

• Marinate meats

• Make dipping sauces

• Dress salads

• Balance curries

• Finish noodle dishes

Many recipes call for just a teaspoon or two, but those few drops make an enormous difference.

Is Fish Sauce the Same as Soy Sauce?

Not quite.  While both add umami, they're made differently and bring different flavors to a dish.

Fish sauce is fermented from fish and salt, giving it a clean, savory depth.

Soy sauce is made from fermented soybeans and often wheat, creating a richer, toastier flavor. They're not interchangeable, but they each have an important place in the kitchen.

Does Fish Sauce Need to Be Refrigerated?

An unopened bottle is shelf-stable. After opening, many people keep it in the pantry, while others prefer refrigeration to preserve its flavor over time. Either approach works, as long as it's stored in a cool, dark place and tightly sealed.

Is Fish Sauce Gluten-Free?

Many traditional fish sauces are naturally gluten-free because they're made with only fish and salt. However, some brands include additional ingredients, so it's always worth checking the label if you have dietary restrictions.

Why Do Thai Cooks Love Fish Sauce?

Because it's one of the easiest ways to build flavor.

Thai cooking is all about balance: sweet, salty, sour, spicy, and umami—and fish sauce plays a central role in creating that harmony. It seasons without overpowering and enhances without taking over.

It's the ingredient that quietly makes everything else taste better.

In Conclusion...

Fish sauce may have a bold reputation, but it's one of the most versatile and indispensable ingredients in Thai cooking.

Used thoughtfully, it doesn't make food taste fishy. It makes food taste deeper, richer, and more complete.

Whether you're making a weeknight stir-fry, whisking together a salad dressing, or simmering a pot of soup, a splash of fish sauce is often the difference between a good meal and a memorable one.

How to Choose a Great Fish Sauce

Not all fish sauces are created equal. While every brand has its own style, there are a few things to look for when you're shopping.

Look for a Short Ingredient List

The best fish sauces are beautifully simple.

Ideally, the label should list just:

• Fish (typically anchovies)
• Salt

Some brands may include a small amount of sugar, but avoid products with long lists of additives or artificial flavorings if you're looking for a traditional, clean-tasting fish sauce.

Consider the Protein Content

On many bottles, you'll see a number followed by °N (degrees nitrogen).

This measures the amount of naturally occurring nitrogen created during fermentation—a rough indicator of protein and flavor intensity.

In general:

• 20–30°N: Great for everyday cooking.
• 30–40°N: Richer, more complex flavor.
• 40°N and above: Premium fish sauce, often enjoyed as a finishing sauce or dipping sauce.

A higher number doesn't necessarily mean "better"—it simply means a more concentrated, nuanced flavor.

Color Matters

A quality fish sauce should have a clear amber to reddish-brown color. If it looks cloudy or muddy, it may be older or made with additional ingredients. My personal favorite is Squid to cook with. Three crab to have on the table. And tipparos if I'm having noodles soups. 

Smell Beyond the First Impression

Yes, fish sauce has a distinctive aroma.

But a great fish sauce should smell savory and pleasantly briny—not harsh or overwhelmingly fishy. Once it's cooked into food, that aroma mellows into rich umami.

Buy What You'll Actually Use

There's no need to start with the most expensive bottle.

Choose a well-made fish sauce you'll feel comfortable reaching for regularly. The best fish sauce is the one that becomes part of your everyday cooking.

Like olive oil or soy sauce, different brands have different personalities. As you cook more Thai food, you'll naturally discover the styles you enjoy most.