the strength of the liquid required, use either 1 tbsp tamarind pulp
soaked in 150ml (1/4 pint) boiling water for 3 tbsp tamarind pulp soaked
in 250ml (8 fl oz) boiling water. The later is obviously a little
stronger. Soak the tamarind pulp in the boiling water for 10 minutes,
then strain the pulp through a sieve, pressing it against the sieve to
extract as much tamarind flavor as possible. Discard the pulp and use
the tamarind liquid.