The reddish brown, curved seed pods of a lovely tropical tree hold several large seeds encased by moist, sticky, dark brown flesh that varies from being very sweet to very sour. The latter is used as one of the primary souring agents in Thai cooking, imparting a delicious fruity tartness to soups, salads, stir-fries and sauces.
When young, the pods are green and fleshy. As they ripen, they turn reddish brown and become brittle on the outside; inside, the rich, dark brown flesh of the fruit is moist and sticky, enveloping a row of bean-like seeds.
The sweet varieties command a high price at the market and are sold in their ripened pods to be eaten fresh as fruits. The province of Petchaboon in northeastern Thailand is known for its sweet tamarind (makahm wahn). Each year, when the fruit comes into season during the dry months, a Sweet Tamarind Fair is held with lots of festivities and lots of delicious tamarind to sample and take home. During this time of year, bags of the plump brown pods are peddled around by street hawkers as well as piled among colourful fruits at fruit stands across the country.