Pla Rah ปลาร้า
Pla rah is fish that has been fermented with toasted rice and salt. Pla rah is primarily made from one of two types of fresh water fish: mudfish (also known as snake head fish or pla chon) and pla gradee (pictured on the right). The mudfish is larger and has more meat. Pla gradee is much smaller and bonier.
Pla rah has a complicated role in Thai cuisine. It is considered peasant food and unfortunately you rarely see it in Bangkok restaurants. It is one of those foods that have no pretensions and many people love. Some people, perhaps because of how pla rah is perceived or the smell, stay away. Give it a try before you decide you like it or not.
Pla rah is relished in Northeastern Thailand and Laos, as parts of Laos once called itself Siam. A few teaspoon is often added in food like som tum, soop naw mai and other dipping sauces. It was traditionally eaten either raw or cooked. However the government has been trying to promote healthy eating by cooking food first so now most people cook it.
Pla rah has an unpleasant smell before it is mixed with other ingredients. When preparing Northeastern food outside of the region, some people drop pla rah, from the recipe. Thai people say that durian that is overripe has gone "pla rah". Also, people who swear far too much have a "pla rah" mouth.
Outside of Thailand, you find pla rah in glass jars. Until recently, the pla rah you'd buy in markets (or make yourself) would still have bones in it so you'd have to strain or pick out the bones, but I have discovered pla rah with no bones. The label on the bottle says, 'Cream Style' and is much easier to use! It looks like a thick paste.