‘Hai Plara’ is a rounded jar with small rim, swollen body and narrow foot. It is an enamelware to prevent the moisture or strong texture earthenware or stoneware. This type of pottery is strong like stone because the clay melt together until water cannot seep through (0.5-2% porosity) which been heated at approximately 1,220 – 1,280 degrees Celsius or in between 1,200 - 1,350 Celsius.
Hai Plara is different from other type of jar; the rim is made into two layers to place ashes to prevent the preserved fish from the flies and cover the jar with ashes covered thick fabric. In northeastern area call it ‘Hai Pla Daek’ or ‘Hai Pla Laek’.
From archaeological evidence found that Hai Plara have been made in Thailand for very long time. Hai Plara were found buried in graves at Ban Non Wat, Non Sung District, Nakhon Ratchasima Province, which aged more than 3,000 years represent the knowledge of food preservation in the past.
Apart from Thailand and northeastern area of Thailand, preserving fish using fish and salt also found in different parts of the world, especially in Southeast Asia. Preserved fish in Thailand called ‘Plara’, in Laos called ‘Pla Daek’, in Cambodia called ‘Prahok’, in Philippines called ‘Bamkung’, Vietnam called ‘Mam’, Malaysia called ‘Pekasam’, Indonesia called ‘Bakasang’ and Myanmar called ‘Ngapi’. Preserved fish with similar ingredients, such as fish, salt and rice, is part of ASEAN culture.