Tamarind

Commonly thought of as a South East Asian souring agent, tamarind is actually used all over the world from India to Africa and Mexico to the Middle East. It comes from the fruit of a large brown, pea-like pod that is soaked in water. The pulp is squeezed and sieved, and it is the sour water that is used. You can buy good-quality tamarind pastes that you soak in warm water and sieve before using. I’d avoid using tamarind concentrates, which are strong and quite bitter. Once opened, keep the tamarind paste in the fridge. Use it within two months, or as directed on the packet.