8 Famous Vietnamese Fermented Fish Sauces from North to South

Vietnam’s culinary culture is known for its incredible diversity in condiments, and fermented fish sauces (mắm) are among the most unique. More than just seasonings, these sauces reflect regional identities, age-old traditions, and the Vietnamese knack for turning humble ingredients into gourmet essentials.

From the northern mountains to the Mekong Delta, here are eight iconic Vietnamese mắm varieties representing the country’s three regions — each with a story and flavor of its own.

1. Tứ Kỳ Fermented Sandworm Sauce (Mắm Rươi) – Hải Dương, Northern Vietnam

Tứ Kỳ district in Hải Dương is known as Vietnam’s “sandworm capital.” The sandworm, locally referred to as rồng đất (earth dragon), is the main ingredient in this rare and seasonal delicacy. After being carefully cleaned, the worms are fermented with salt for at least three months.

The resulting sauce has a golden, honey-like hue and a rich, savory aroma. It’s best enjoyed with boiled pork, steamed goat meat, roasted duck, or wrapped in fresh spring rolls with herbs and vegetables.

2. Cà Cuống Essence Fish Sauce (Mắm Cà Cuống) – Ninh Bình, Northern Vietnam

Made from whole male giant water bugs (cà cuống), this rare sauce is soaked in pure fish sauce for at least 30 days. When opened, it releases a minty, camphor-like fragrance that’s surprisingly refreshing.

It’s often served as a dip for boiled pork or Vietnamese sausage (giò chả), and famously accompanies Thanh Trì steamed rice rolls (bánh cuốn Thanh Trì), adding depth and aroma to the dish.

3. Thanh Hóa Shrimp Paste (Mắm Tôm) – North Central Vietnam

Mắm tôm from Thanh Hóa is a bold, pungent paste made from fermented tiny shrimp (ruốc) and sea salt. After being aged, it develops a signature purple hue and intense aroma.

This paste is a staple in many northern dishes, especially with grilled catfish in galangal (cá lăng nướng riềng mẻ). The fish’s smoky flavor pairs perfectly with the tangy shrimp paste and a variety of fresh herbs.

4. Fermented Sandworm Fish Sauce (Mắm Sá Sùng) – Quảng Ninh, Northern Vietnam

Quảng Ninh’s mắm sá sùng is made from sun-dried peanut worms and anchovies, fermented in clay jars with sea salt. This slow natural fermentation gives the sauce a caramel hue and honey-like consistency.

Commonly used in the famous Hạ Long squid cakes (chả mực), it brings an umami-rich flavor that enhances seafood dishes.

5. Fermented Small Fish Sauce (Mắm Cá Rò) – Huế, Central Vietnam

Native to Huế, this sauce is made from a small local fish called cá rò, similar to anchovies. The fish is cleaned using sea salt water and then packed tightly in jars with more salt to ferment.

Once aged, it’s typically seasoned with garlic, chili, toasted rice powder (thính), and sugar to create a balance of salty, sweet, and savory. This sauce is served with boiled meats, vegetables, or hot rice.

6. Pineapple Fish Sauce (Mắm Thơm) – Phú Yên, Central Vietnam

A local specialty of Phú Yên, mắm thơm is made by blending fermented anchovies with ripe pineapple. The pineapple adds a tropical acidity and sweetness to the sauce.

It’s famously used in chicken braised in pineapple fish sauce (gà kho mắm thơm), a fragrant dish featuring tender chicken simmered in the aromatic blend of sweet-sour pineapple and salty fish sauce.

7. Fermented Krill Paste (Mắm Ruốc) – Long An, Southern Vietnam

Mắm ruốc is a southern staple made from tiny krill (ruốc), fermented with salt until it turns pinkish-brown with a strong, distinctive smell.

One popular dish is stir-fried pork with fermented krill and lemongrass (mắm ruốc xào thịt sả), often eaten with hot rice or crispy rice. This dish brings together saltiness, umami, and the fresh aroma of lemongrass.

8. Fermented Linh Fish Sauce (Mắm Cá Linh) – Châu Đốc, An Giang, Southern Vietnam

Châu Đốc is considered the “fermented fish capital” of Southern Vietnam. Its most iconic product is mắm cá linh, made from young linh fish mixed with salt and roasted rice powder, then aged in clay jars.

This sauce is the star ingredient in dishes like mắm hotpot (lẩu mắm) and steamed fish paste with egg (mắm chưng trứng), offering a rich, savory, and spicy flavor that defines Mekong Delta cuisine.

Final Thoughts

From mild to intense, sweet to salty, Vietnam’s fermented sauces offer a taste of the country’s cultural and culinary depth. Whether you’re trying a Northern rice roll with mắm cà cuống or diving into a Southern lẩu mắm, these sauces bring authenticity and tradition to every bite.

Looking to explore more of Vietnam’s authentic flavors? Discover our curated Vietnam culinary tours or browse regional food experiences across the country.