Fish Sauce: What It Is, How to Use It, and Substitutes

Anyone who has tried making pad Thai or Vietnamese pho at home knows the secret isn’t a rare spice — it’s a bottle of fish sauce. This ancient fermented condiment, made from anchovies and salt, delivers a depth of umami that transforms dishes.

Fermentation time: Up to 2 years ·
Sodium per tablespoon: 1670 mg ·
Primary protein source: Anchovies, krill ·
Regional names: Nam pla, nuoc mam, patis

Five essential facts define fish sauce — one pattern: each tells you something about its origin, composition, or quality.

The implication: fish sauce is a concentrated source of umami and sodium — small amounts go a long way.

What is fish sauce made of?

Fish sauce ingredients

• Fish sauce is made from fish or krill coated in salt and fermented (FAO (international food standards body)).
• Common fish used include anchovies, mackerel, or sardines.
• Squid brand uses anchovies and salt, fermented 18 months.

The fermentation process

• Fish sauce is made by layering fish, typically anchovies, with salt and fermenting for a year or more (Epicurious (food magazine)).
• The FAO (international food standards body) defines fish sauce as a product made by fermentation of fish and salt, possibly with other ingredients added to assist fermentation.
• The standard does not apply to fish sauce produced by acid hydrolysis.

Regional variations in fish sauce production

• Vietnamese fish sauce (nuoc mam) tends to be lighter and sweeter; Thai (nam pla) tends to be saltier; Filipino (patis) tends to be heavier (Epicurious (food magazine)).
• Laotian padaek is a thick, sometimes unfiltered fish sauce that may contain bits of fish (Tasting Table (food publication)).
• Japanese shottsuru is a mild fish sauce variety, while ishiru is sometimes made from squid rather than fish (Tasting Table (food publication)).
• Korean aekjeot is an umbrella term for multiple types: myulchi aekjeot from anchovies, kkanari aekjeot from sand lance, and saeujeot from shrimp (Tasting Table (food publication)).

The implication: fish sauce’s simplicity belies its complexity across regions.

Is fish sauce good or bad for you?

Nutritional profile of fish sauce

• High sodium content: 1670 mg per tablespoon (Epicurious (food magazine)).
• Contains amino acids and umami compounds from fermentation.
• Low in calories and fat.

Health benefits of fish sauce

• Provides protein-derived amino acids.
• Adds flavor without added sugar or artificial additives.

Potential risks: sodium and allergies

• Not suitable for low-sodium diets or individuals with seafood allergies.
• May contain histamine for sensitive individuals.

Who should avoid fish sauce?

• People on low-sodium diets should avoid it.
• Anyone with fish or shellfish allergy.
• Those with histamine intolerance may react.

How fish sauce compares to other sauces

• Fish sauce is high in sodium but not the most unhealthy sauce; sauces with added sugar and saturated fat are worse.

The takeaway: fish sauce is a trade-off between flavor and sodium.

What does fish sauce taste like?

Flavor profile: salty, umami, and fishy

• Strong, pungent fishy aroma.
• Adds depth and umami (Epicurious (food magazine)).

How fish sauce compares to soy sauce

• Fish sauce is thinner and more pungent than soy sauce.
• Slightly less salty than soy sauce when diluted.

The role of fish sauce in cooking

• Balances flavors in Thai and Vietnamese dishes.
• Works as a secret umami booster in marinades and dressings.

The pattern: fish sauce’s pungency is the key to its culinary power.

What can I substitute fish sauce with?

Best fish sauce substitutes: soy sauce, tamari, and miso

• Soy sauce plus lime juice mimics fish sauce.
• Healthline lists 8 tasty substitutes.

Umami alternatives: mushroom sauce, seaweed

• Vegan options include mushroom sauce.
• Seaweed lends a briny note.

Making your own fish sauce substitute

• Combine soy sauce with lime juice and a pinch of garlic.

When to use each substitute

• Substitute ratios depend on dish — start with half the amount.

What this means: substitutes exist but none replicate fish sauce’s exact profile.

What is another name for fish sauce?

Regional names: nam pla, nuoc mam, patis

• Thai: nam pla.
• Vietnamese: nuoc mam.
• Filipino: patis.
• Korean: saeujeot is similar but different.

How names reflect local ingredients

• Korean myulchi aekjeot indicates anchovy base; kkanari aekjeot uses sand lance (Tasting Table (food publication)).

Brand names and variations

• Red Boat is a premium Vietnamese fish sauce brand associated with Phu Quoc.

The catch: using the right regional name ensures authentic results.

Fish Sauce vs Soy Sauce: A Comparison

Three key differences, one theme: fish sauce brings a distinct funk that soy sauce cannot replicate.

The pattern: fish sauce is saltier and funkier, soy sauce is more versatile. Both add umami but in different directions.

For home cooks exploring Southeast Asian flavors, the choice is clear: pick a fish sauce that matches your dish’s origin and use it sparingly to unlock authentic depth — or risk missing the soul of the cuisine.