The taste of sourness comes in many flavours and nuances. Lemons and lime have a fresh, fruity, eye-widening sharpness that is perfect for sweet treats such as lemon tarts. Vinegars span the acid range from rugged, throat-ripping concoctions that, judiciously used, subtly counter the richness of meat stews, to the mellow acidity of traditional balsamic vinegar that can be sipped as an aperitif or digestif.
What is Tamarind?
Tamarind (Tamarindus indica ), with its delicate but perky acidity, is the souring agent of choice of tropical Asian cuisines. Its flavour as been described as akin to a sour date, which probably inspired the Arabic name tamrhindi ("Indian date") from which the English word is derived. That the Malay/Indonesian word for tamarind, asam (or assam ), is the same as that of the (now) north-eastern state of India reinforces the suggestion of Indian-Burmese (Myanmar) roots. In fact, this fruit of a tall, spreading tree of the pea family has its origins in the tropical savannah of Africa, but came to southern India in prehistoric times, when there was still a land bridge between the two continents, and spread through tropical Asia.
Buying & Preparing Tamarind
The legume-like fruit pods have a brittle shell encasing rich brown acidic fibrous pulp surrounding small bean-sized seeds. Outside of the tropics where the fruit is readily available fresh, tamarind is sold as compressed blocks of dried pulp and seed or de-seeded pulp. Sometimes salt is also added. Check the labelling - the unsalted variety is preferable.
How to reconstitute dried tamarind for use:
Break off a lump from the block. (The rest of the block can be kept indefinitely, tightly wrapped and stored in a cool dry place. I keep mine in the fridge.) Soak the lump in warm water for a few minutes to soften, then work the pulp with your fingers to loosen the pulp from the fibres and seeds (if any). As a rough guide, use about 3 tablespoons of seedless tamarind pulp to 250 ml water. Double the quantity of pulp if it contains seeds as well. (You don't have to be too concerned about precision of the measurements here as you will be adjusting the amount of tamarind extract used in a dish to taste.) Squeeze the mass with your hands over a clean bowl to extract the pulp. Discard the fibres and seeds.
Cooking with Tamarind
The soft fruity acidity of tamarind provides a harmonious acid counterpoint for the richness of coconut milk in the curries of southern Indian and South -East Asian cuisines. It adds a perky note to sauces, chutneys and relishes in these cuisines. The very British Worcester sauce, based on an Indian recipe brought back to Britain by ex-Governor General of Bengal Lord Marus Sandys, includes tamarind. Tamarind liquid is essential for the South Indian coconut and mint chutney that accompanies thosai (fermented rice and lentil pancakes), idli (steamed fermented rice cakes), and various fritters. A highly potent tamarind, chilli and garlic sauce is the quintessential flavour of Myanmar. In dishes of sweet-sour flavours where the fragrant palm sugar provides the sweet profile, tamarind rather than vinegar gives the right tone of sourness.
Tamarind's flavour takes centre stage in the myriad sour, soupy dishes of these hot climates. South Indian cuisine features a raft of watery spiced "soups" called rasam in which tamarind provides the characteristic tangy piquancy.
The refreshing sourness of tamarind in combination with the heady fragrance of bunga kantan (torch ginger) makes the Penang speciality Gulai Tumis (sour fish curry) appealing even on sweltering humid days.
Another popular tamarind dish is Assam Hae (Tamarind Prawns). It's very simple to make: marinate whole large prawns (with shell between head and tail removed, and deveined) in a thick tamarind liquid with a pinch of salt and sugar for at least an hour. Heat a few tablespoons of oil to smoking hot in a wok and stir fry the prawns until they are dark brown on both sides. Serve with sliced cucumbers.
For the Filipino sinigang , a soupy, sour stew of fish or shrimps or meat that is often regarded as that country's national dish but in fact has countless regional variations, the unripe pulp of fresh tamarind is preferred.
Tamarind outside the kitchen
Tamarind is valued not only as a cooking ingredient, but also for its properties as a cooling and cleansing agent for the body, particularly for the liver and kidneys. Indeed, the Burmese believe that the body can cooled in hot weather simply by sitting under the tamarind tree. Tamarind pulp is made into a cordial base which is diluted with icy water for a very refreshing drink.
Semi-dried candied tamarind, sometimes spiced with a little chilli, is popular throughout Asia and can be found in most Asian food stores in the West. There is also a sweet variety of tamarind which is eaten fresh.
Other "Types" of Tamarind
If imitation is indeed the highest form of flattery, tamarind should have a really huge ego. So great is the appeal of this fruit that in countries where tamarind itself is popular, the name is also applied to many unrelated sour fruits. The acid tropical African fruit Dialium guineense is called white, or velvet, tamarind.
In Malaysia and Indonesia, a sour relation of the delightfully sweet mangosteen (Garcinia mangostana ) is called asam gelugur (G. Atroviridis). Asam , the Malay/Indonesian name for tamarind, also means sour.
Sold as thin, dried slices usually labelled tamarind pieces or slices, asam gelugur is used primarily in soupy dishes where both high levels of acidity and clarity of broth are needed. One example is the Penang Assam Laksa. The term "laksa" refers to spicy soupy noodle dishes of which the most well-known internationally is the curry laksa where of wheat and/or rice vermicelli noodles or flat rice noodles are served in a spicy coconut milk soup, usually with chicken and possibly some prawns, slices of fish cakes and cockles. The Penang Assam Laksa however comprises slippery fat cylindrical rice noodles topped with lots of mint, cucumber and pineapple, all in a more-ishly sour fishy broth that is redolent of bunga kantan (torch ginger flower). Finely flaked mackerel adds body to the otherwise clear tangy broth.
Recipe: SAYUR ASAM (Indonesian sour vegetable 'soup')
This Indonesian soupy dish has many regional variants, but is always eaten with steamed rice and fried salted or fresh fish. The liquid is both drunk as a soup and poured over the rice so that you end up with quite a sloppy dish, which contrasts well with the crispness of the fried fish.
1 onion, finely chopped
25 - 30 g dried asam gelugur slices
Aprpox 2 - 2.5 lt water
Salt to taste
100g raw peanuts
200g snake beans or French beans
3 cobs of corn, husks removed
A handful of thinly sliced cabbage (optional)
15 dried shrimp, soaked in hot water until softened
4 large red chillies
2 thin slices belachan (shrimp paste), available from Asian grocers
2.5 cm fresh or frozen galangal, grated
2 cloves garlic
1 tomato, roughly chopped
Drain the soaked dried shrimps. Using a food processor or mortar and pestle, grind the spice paste ingredients to a smooth paste.
In a large pot over high heat, combine the spice paste, onion, asam slices, water and salt. When it comes to the boil, add the peanuts and simmer, covered, for about 30 minutes. Cut the beans into 5 cm lengths. Cut each corn cob into 3 - 4 pieces. Add vegetables (including cabbage if using) to the soup. Simmer for about 30 minutes (the vegetables are not meant to be al dente).
Serve hot with steamed rice.