Place tapioca flour or starch in a bowl.
Place black food color in a separate bowl and add a tablespoon of hot water to the food color.
Add the rest of the water directly to the tapioca flour and pour the colored water to the bowl as well.
Mix tapioca flour and water with a fork until they start to stick together.
Transfer to a flat surface and knead until the dough becomes smooth.
Divide the dough into 2 and roll each forming thin sticks. Cut them into small pieces. Try to make them as even in size as possible and should be small enough to pass through your straw.
Roll each piece in between your palms to make them round.
Bring 2 cups of water to a rolling boil in a small pot or saucepan.
Add the tapioca pearls to the boiling water and let it cook for 15 minutes or longer until the desired consistency (soft or chewy) is achieved. They will also become darker as they cook.
Remove from heat and let it rest for a few minutes. They will shrink back to the original size and will turn black at this point.
Transfer tapioca pearls into a sugar syrup or a bowl with a little water to prevent them from sticking together.