Is there anything that’s more of an umami bomb than fish sauce? A few drops of this magic stuff into a dish can take it from from great to spectacular. It’s an amazing secret ingredient to have in your arsenal.
This is the ultimate guide to fish sauce for anyone who is curious or interested in adding it to your culinary toolkit. In this post, you’ll learn what it is, what brands to buy, how to use it, and most importantly, how to make prepared fish sauce for dipping or dressing at the table.
My family’s fish sauce roots run deep. We’re from a countryside village by the ocean. Several times a year, boats would come to the docks with the various in-season seafood for the villagers to make fish sauce with. Every household would have their own barrels of fish sauce. The rich family in the village made their money selling industrial quantities of the stuff, made in large open air concrete pools. My mom was famous in the village for her prepared fish sauce which she sold with bowls of noodles and fresh grilled cobs of corn.
Nuoc mam vs nuoc cham
Sometimes on restaurant menus you’ll see a reference to nước chấm. Nuoc cham in Vietnamese just means dipping sauce, but what it really means is ready-to-eat/table/prepared, aka fish sauce made into a ready to eat sauce (ie, for dipping) with garlic, lime, and chilies. Very few people would use the raw unadulterated sauce out of the bottle for anything other than cooking.
In my family and in our part of Vietnam, we don’t say nuoc cham. We just say nuoc mam and you’re expected to know which kind is meant based on context. At best, it would be called nước mắm chấm, which means dipping fish sauce. If you are cooking, you use it right out of the bottle, but at the table, it’s always prepared.
Prepared fish sauce is the stuff of dreams, and almost always a jealously guarded family secret. Every Vietnamese family claims their recipe is the best, or that their family makes it the best. Vietnamese kids who have grown up in America and can’t cook as well as their moms joke about always having 2 jars in their fridge. When one goes empty, it’s time to call mom up for another jar.
Prepared fish sauce recipe
When Vietnamese people say their mom’s fish sauce is the best, they mean the prepared stuff. Heck, when Vietnamese people say they dream of fish sauce, they also mean the prepared stuff. Not many Vietnamese people would share this recipe (or could, since most don’t measure or write recipes).
This is a version I learned long ago from my mom and tweaked through the years by me, and best of all, written down.
How to make prepared fish sauce
- Crush sugar, garlic, and Thai chilies in a mortar and pestle.
- Transfer to a jar, then add lime, fish sauce, and water.
- Let mellow in the fridge for at least 30 minutes before enjoying.
An even better (and cheaper) version
It’s 2025 and limes are ridiculously priced and not that great. I’ve started making and serving our ginger fish sauce which is traditionally eaten with poultry, but all the time. And it’s been a hit. I’ll update the recipe below but basically, it’s sub lime for ginger and add a little more sugar and garlic to offset the punch of ginger. Otherwise every step is the same. I’ve loved it with everything you’d traditionally eat with nuoc cham, such as spring rolls, salad rolls, rice plates, etc.
What is fish sauce
Fish sauce, sometimes referred to as nước mắm, is a sauce made from fermenting seafood in salt that’s associated with Southeast Asia, especially Vietnam and Thailand. Generally it’s made from anchovies, but it’s also made from tiny shrimp, tuna belly, and more. You can make fish sauce from any seafood. You can even make fish sauce at home by packing 3 parts fresh anchovies to 1 part salt in a large jar and leaving it for a year or so.
What brand of fish sauce to buy
Of course, no one is going to make their own at home. There are a lot of brands of fish sauce out there, and more all the time, so it can get confusing as to which one to choose.
The best way to choose is the same as olive oil. There’s something similar to first press for fish sauce that has a superior flavor over the cheaper stuff. To find it, look for the words mắm nhĩ on the label. This includes the popular and well known Red Boat brand, but it also includes some other great choices such as Viet Huong, Phu Quoc, and our current bottle of the moment, Megachef.
What is mam nhi
Most Vietnamese people know that mam nhi is to fish sauce what extra virgin is to olive oil but not everyone knows why. The etymology of the phrase was a hard one to track down. There’s not even agreement on the correct spelling. Esoterically, it’s either mắm nhĩ or mắm nhỉ. These are pretty small differences, even in Vietnamese, but it’s still not agreed upon.
On Vietnamese wikipedia it merely says that mam nhi means “proper sauce” but the explanation is a little stretched and unlikely. My dad’s theory is that nhĩ is old school slang for drip or drop. Way back in the day, before mass manufacturing, every family would have wooden barrels like a wine barrel with a spout in which they made the sauce. When they needed some, they would open the spout and let some sauce drip out, and that’s what was called mam nhi.
Per my dad’s theory, if they were planning on selling it, they would pour some of those first drippings back into the barrel and later press it to stretch the yield, which formed the inferior “ordinary” fish sauce. Mam nhi was the good stuff, saved for the family.
Avoid this unless you know
Over the years I’ve learned that many people don’t know what brands and styles to avoid. The kind we use in most cooking is clear. Avoid any that are opaque unless you know what you are getting into, including – and especially – any that say mắm nêm or mắm ruốc on the label. These will be more pungent than the clear stuff. Used correctly as in BBH, they’re delicious, but be warned, they can be dangerous for the uninitiated sense of smell.
You should also avoid any supermarket brands, such as Thai Kitchen, Asian Family, Dynasty, etc because they’re overly pungent, over salted, and lacking in flavor. When in doubt or in a food desert, buy Red Boat. It’s the safest, most widely available option, and it’s what we buy when we’re far from Asian supermarkets.
Can you make this without a mortar and pestle?
When my mom needs to make enough for large parties (we’re talking gallons) she would use a food processor or blender. She considered it substandard but no one seemed to complain. I’ve made it both ways, there’s a very clear – but not huge – difference. The best tool for the job if you don’t have a mortar and pestle in my opinion is a garlic press.
Can you use lemons?
You can use any acid you want, even vinegar, but limes are best. Everything else doesn’t taste quite right.
Can you use other peppers or just leave them out?
Thai chilis are traditional because that’s what’s in that part of the world, but sometimes it’s just a little hard to come by. My favorite substitute is habaneros, which are easier to seed if you don’t prefer the spice, and give the fish sauce a nice fruit forward flavor as well. If you don’t like spice, you can avoid them altogether, in which case Vietnamese people often add julienned carrots for a little flavor, sweetness, and color.
Variations
This simple basic fish sauce is not the only game in town. We modify it to suit the dish. You can add ginger for poultry. You can make a more watered down one to flavor vermicelli bun bowls. Add carrots for color. My mom even makes a meaty version that’s essentially gravy that Steph adores for dipping spring rolls, like a peanut free peanut sauce.
Basically, feel free to play around with it to get it right for both your taste and your dish.
Vietnamese vs Thai fish sauce
In my family, there’s no real difference between the Vietnamese and Thai versions, they are interchangeable to us and we use whatever we have on hand.
Fish sauce substitutes
It may be tempting to substitute if you come across a recipe that requires fish sauce, but you shouldn’t. In the same way you probably wouldn’t substitute mustard in a recipe, unless you’re vegan, you probably don’t need to substitute. It’s cheap and there’s lots of recipes you can use it with, in addition to just using it to boost the umami profile of literally anything from steak to ragu bolognese.
Recipes that use fish sauce
If you end up with a lot of fish sauce and you don’t know what to do with it, here are some of my favorite recipes that use it:
- Crockpot Beef Stew
- Instant Pot Bo Kho Recipe
- Spicy Noodles: Vietnamese Garlic Lemongrass Edition
- The Best Pho Recipe
- Coconut Chicken Curry
- Khao Soi: 15 Min Thai Coconut Curry Chicken Noodle Soup
- Bun Bo Hue: The Noodle Soup You Never Knew You Loved
- The Mushroom-iest Green Bean Casserole
- Better than Take Out Peanut Free Pad Thai Recipe
- Extra Easy Pok Pok Style Fish Sauce Chicken Wings
Recipes that use prepared fish sauce
- Vietnamese Spring Roll Recipe
- A Very Authentic Countryside Bún Bò Xả Ớt – Vietnamese Lemongrass Beef Recipe
- Lemongrass Beef Salad Rolls
- Vietnamese Steak Summer Rolls Party!
- Chashu Summer Rolls Recipe
- Smoked Salmon and Avocado Summer Rolls
- Avocado Chicken Broccoli Rabe Summer Rolls
- Hainanese Chicken Summer Roll Recipe
Fish Sauce Recipe
Ingredients
- 2 tbsp sugar or less if you prefer it less sweet
- 2-4 Thai bird’s eye chili sliced, more or less depending on your spice tolerance
- 2 cloves garlic crushed
- 2 tbsp fish sauce mam nhi preferred, such as red boat
- 1.5-2 tbsp lime juice depending on taste
- 2/3 cup water see notes
Special Equipment
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mortar and pestle
Instructions
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In a mortar in pestle, crush sugar, garlic, and half the Thai chilies.
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Transfer to a jar, then add fish sauce. Add 1/2 lime and water. Taste and add lime as needed. Finish with remaining Thai chilies.
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Let mellow in the fridge for about 30 minutes before enjoying. Keeps in the fridge for up to a month.
Notes
For Ginger Fish sauce, use 1 tbsp grated/diced/crushed ginger (about 3/4” of ginger), 3 tbsp sugar, 4 cloves of garlic, 2 tbsp fish sauce, 1-2 thai chilis (optional as the ginger is quite spicy itself), and 1 cup water. Then just follow the steps above.
Estimated Nutrition
