What Vietnamese fermented shrimp seasoning is known as mắm ruốc?

Mắm ruốc is a Vietnamese fermented shrimp seasoning made from small shrimp and salt.

The shrimp are salted and fermented, producing a dense paste with a powerful savory aroma and pronounced umami flavor. Mắm ruốc is especially associated with central Vietnam, including Huế, where it is used in soups, stir-fries, dipping sauces, and meat or seafood preparations.

It is related to mắm tôm, another Vietnamese shrimp paste, but the two names are not interchangeable in every regional context. Mắm tôm is often darker, sharper, and commonly served as a dipping sauce, while mắm ruốc is frequently cooked into dishes or diluted and seasoned with aromatics.

Like other fermented Vietnamese seasonings, mắm ruốc is valued for adding depth rather than serving as a mild table condiment. Its strong smell can be surprising to newcomers, but cooking usually rounds out its flavor.