Pla Ra

If fish sauce is the salt of central Thai cooking, pla ra is the salt of Isaan. It is fermented freshwater fish: thick, cloudy, very pungent, and loved across the northeast and Laos, where it is called padaek. For many Isaan cooks, food without pla ra simply does not taste like home.

How it is made

Freshwater fish from rice paddies, rivers and reservoirs, such as snakehead or gourami, are cleaned, salted and packed in jars with rice bran or roasted ground rice. The jars are sealed and left to ferment for months, sometimes years. The fish breaks down into a thick, grey-brown mash with chunks of fish and a rich, strong smell.

How it differs from fish sauce

Fish sauce is clear, filtered liquid from salted sea fish. Pla ra is cloudy, chunky and made from freshwater fish with rice, so it tastes earthier and funkier. They are not interchangeable: replacing one with the other changes the dish completely.

How to cook with it

Traditionally, the liquid and some of the fish are boiled together with lemongrass and makrut lime leaves, then strained to make nam pla ra, a cooked pla ra sauce. This is what goes into som tam pla ra (also called som tam Lao or tam Lao), the funky papaya salad loved across Isaan, and into jaew bong, a thick chilli relish.

It also seasons gaeng om (herb curry), gaeng pa (jungle curry), and many soups and stews of the northeast.

Buying it safely

Raw pla ra should always be cooked before eating. The easiest option outside Thailand is bottled, pasteurised “pla ra sauce” (nam pla ra or nam pla ra pasteurised), sold in Thai grocers, which is cooked, strained and ready to use. Keep it in the fridge once opened.

Cook’s tip

Start with a teaspoon in som tam alongside the usual fish sauce, and work up from there. Pla ra is an acquired taste, and a little goes a long way.