Mekhong is named after the Mekhong River, which marks Thailand's eastern border with Laos after a border conflict between Thailand and France erupted. The patriotic sentiment which arose in Thailand as a result of this conflict greatly benefited the fortunes of this new spirit. Although often referred to as a 'Thai Whiskey', it is in fact a type of flavoured rum, made from 95% molasses and 5% rice using a 6-8 week fermentation process. The rice is added to the molasses and both are fermented together before being double distilled in a pot still with the final distillation at around 69% alc./vol.. This base spirit is blended with indigenous herbs and spices and sweetened with honey. There is no ageing process and Mekhong's rich brown colour is mainly due to the addition of caramel.
Mekhong was Thailand's first locally produced brown spirit and has since become the country's national spirit. Prior to its launch in 1941 only foreign spirits were available in Thailand, with whiskey dominating the local market, so it is perhaps not surprising that when Mekhong was first launched it was known as 'Thai whiskey'. It was an instant success, almost totally dominating the domestic brown spirits market until well into the 1980s, when other similar spirits such as Hong Thong and SangSom were introduced. Today Mekhong is the second best-selling brown spirit in Thailand, with annual sales of 18 million litres.