Place the black rice in a fine mesh strainer and rinse under cold running water for about one minute, stirring gently with your fingers.

Transfer the rinsed rice to a medium saucepan and add 2 cups of water and 1/2 teaspoon of salt, stirring once to combine.

Place the saucepan over medium-high heat and bring the water to a rolling boil without covering.

Reduce the heat to low, cover the saucepan with a tight-fitting lid, and simmer undisturbed for 30 minutes.

After 30 minutes, remove the lid and check one grain for tenderness; the rice should be tender with a slight bite and no standing water should remain.

Remove the saucepan from heat and let the rice rest, covered, for 5 minutes off heat.

Use a fork to gently fluff the rice and stir in 1 tablespoon of butter if using, folding it in gently to separate the grains.