Bengal (both West Bengal and Bangladesh); the earthenware-set sweet yoghurt tradition is uniquely Bengali; associated with Bogra district in Bangladesh for the most celebrated mishti doi
Mishti doi (মিষ্টি দই) is the Bengali sweet yoghurt: thick, unctuous, and set in individual earthenware matkas (মাটির ভাঁড়) that absorb the excess whey and impart a characteristic earthy undertone impossible to replicate in any other container. The technique begins with slowly reducing whole milk (sometimes with evaporated milk added) to concentrate the protein and fat, then caramelising sugar (the caramel gives mishti doi its signature amber colour and caramel-milk flavour), combining the caramelised milk with yoghurt starter (দই বীজ), and setting in the earthenware pots overnight. The clay's porosity is the secret: it wicks moisture from the yoghurt, producing a firmer, denser set without refrigeration techniques.
Eaten as a dessert, alone, with a spoon from the pot. In Bengali culture, mishti doi ends a formal meal. The earthenware pot imparts a mineral, earthy undertone to the yoghurt that distinguishes it from any commercially produced version.
{"Reduce milk to 75% of original volume before adding caramelised sugar — concentrated milk proteins are necessary for the firm set","Caramelise the sugar separately to a light amber before adding to the milk — this is where the characteristic colour and flavour comes from","Allow the sweetened milk to cool to exactly 40–42°C before adding the starter — above 45°C kills the culture; below 38°C produces insufficient activity for proper setting","Use unglazed earthenware (matka) only — glazed or metal containers prevent whey absorption and produce a looser, wetter yoghurt"}
A practitioner uses a small amount of previous mishti doi as the starter (দই বীজ) rather than commercial yoghurt — the native culture in the earthenware itself contributes to the flavour over time, which is why old dairy shops (মিষ্টির দোকান) have mishti doi that improves year on year. The pots should be kept covered in a warm room for 8 hours to set; chilling after setting is optional but firms the texture further.
{"Setting in glass or metal containers — no whey absorption; the result is sweet yoghurt, not mishti doi","Adding starter to hot milk — kills the culture; the milk must be at the precise 40–42°C window","Skipping the caramelisation — plain sugar produces white sweet yoghurt; the caramel is the defining flavour compound"}