Kokum

Although I've eaten the fruits of the closely related mangosteen (g. mangostana), I've have yet to experience using this spice in cooking.

Kokum tree	Kokum fruits ripening	Dried kokum fruits	Kokum butter

Species:	Garcinia indica.
Origin:	Southern Asia.
Source:	Kokum is of Western Indian origin. It grows wild in the forests of Goa and today is widely cultivated in the nearby Konkan region of Maharashtra, both locations sharing the advantages of very good sunshine, adequate rainfall and rich soil.
Used Part:	The name kokum as a culinary spice refers to the dried, soft, outer skin of the fruit of the tropical evergreen tree, garcinia indica. The seeds, fruits, bark, young leaves and extracted oils of the tree are also of culinary value. The seeds contain 23-26% oil, which remains solid at room temperature and is used in the preparations of chocolates, medicines and cosmetics.
Family:	Clusiaceae (St. John's wort family).
Effect:	Kokum has an agreeable flavour and a sweet, acidic taste.
Etymology:	The genus name garcinia was given to the plant by Linnaeus in reference to the English explorer Lawrence Garcin (1683-1752), in honour of his plant-gathering work in India (this geographic reference also being the origin of the species name indica). The alternative species name mangostana (English mangosteen) is derived from the Indomalayan vernacular name of the species mangustan.
	The derivation of the plant's common name kokum or cocum is from the Marathi kokam or kokamb "mangosteen" (cf. Malay mangustan). Several modern names refer to the solidified extract from the fruit which can be used as a spiced butter or as a perfumed candle wax, e.g. English Goa-butter and Indian tallow.
Uses:	Kokum is a versatile Indian speciality spice which ranks highly by both culinary and medical standards. The major culinary uses of kokum are as a garnish for curries and in the preparation of syrups. Exported mainly in the forms of fruits, oil "kokum butter" and syrup, kokum has become increasingly popular in the US, UK, Canada, Australia, Hong Kong and the Middle East.
	Kokam adds acidity to curries in much the same manner as tamarind and the two are sometimes used interchangeably. Adding a few pieces of kokum to a curry during cooking adds the pleasant fruity flavour and agreeable acidic bite particularly characteristic of South Indian dishes.
	Kokum juice extracted by soaking pods in water for an hour and straining off the liquid is an ingredient in several recipes for varieties of vegetarian khadi dish, both dhal-based and yoghurt-based types. These are usually prepared with a mix of fried coriander, cumin and mustard seeds, asafoetida, curry leaves, chillies, gram flour, salt, sugar and coriander.
	Kokum is also used in large quantities in Maharashtra to produce a juicy, citrusy fruit of bright red colour. A soft drink (sherbet) is prepared with the juice of the fruit, the natural sourness of which is counterbalanced by the addition of sugar.
	The kokam fruit also has therapeutic medicinal value as a cholagogue, coolant, demulcent, emollient and antiseptic. The bark and young leaves are a useful astringent and the essential oil is a smoothing emollient.