Break the tamarind pulp into small pieces. Check for any remaining seeds, hard shell fragments, or coarse fibers and remove them. Even products labeled seedless can contain an occasional seed.

Heat the Water

Place the tamarind and 3 cups water in a medium saucepan. Bring to a gentle boil over medium-high heat, then reduce the heat to maintain a low simmer.

Simmer for 10 minutes, stirring occasionally and gently pressing the tamarind with a wooden spoon to help it soften. Allow approximately 15 minutes total for heating and simmering.

Remove the saucepan from the heat. Let the tamarind soak in the hot water for 20 minutes, until soft enough to break apart easily with a spoon.

Stir and mash the softened tamarind gently with the wooden spoon. Keep all the soaking liquid; it forms the base of the drink.

Set a fine-mesh strainer over a large heatproof jug or bowl. Pour in the tamarind mixture. Press and stir with the spoon to push the liquid and soft pulp through. Discard the tough fibers and any seeds left in the strainer.

Add the sugar to the strained liquid while it is still warm. Stir until completely dissolved.

Stir in cold drinking water gradually until the finished drink measures exactly 6 cups. Transfer to a serving pitcher. The amount of added water will depend on evaporation and how much pulp passes through the strainer.

Taste the juice. It should have a clear tamarind flavor with a balance of sweetness and tartness. If needed, add extra sugar 1 tablespoon at a time, stirring until dissolved. See the notes for a less-sweet variation.

Cover and refrigerate for approximately 2 hours, or until thoroughly cold. Refrigerate promptly after adding the cold water rather than leaving the pitcher on the counter to cool completely.

Stir well before pouring. Divide among six glasses, allowing approximately 1 cup of juice per serving before ice. Add ice to individual glasses if desired.