The marked taste for sour amongst Indonesians must have developed from the wealth of ingredients at hand. Here are some exotic local fruits I haven’t included in my recipes: the sourness in Acehnese cooking comes from the sun-dried bilimbi fruit and gelegur gives tang to Batak cuisine (often used in clear broths as it doesn’t have the brown colour of tamarind). Asam kandis is a lip-puckeringly sour fruit, whilst the fruit of the torch ginger is more refined with
aromatic notes of lemongrass and ginger. It is used in fish dishes in
South Sulawesi.