The Thai name for fermented fish sauce is nam pla.
Nam pla, literally “fish water,” is Thailand’s standard fish sauce and one of its most important seasonings. It is made by mixing small fish—often anchovies or related species—with salt and allowing the mixture to ferment until proteins break down into a savory, amber liquid.
Commercial production commonly ages the fish for about 12 to 18 months. The first liquid pressed from the fermenting mixture is considered the highest grade, while later pressings are diluted or further processed for cooking. Nam pla is used both in recipes and as a table condiment.
It is not the same as pla ra, a fermented fish paste associated particularly with northeastern Thailand. A familiar table preparation is phrik nam pla, which combines fish sauce with lime juice and chopped bird’s-eye chilies. Nam pla can also be confused with Vietnamese nước mắm, but that is the Vietnamese term for a related fish sauce.