They can be white or light-brownish, and can be a little smaller or a little larger than a mustard seed.
Commercially, the starch pearls are made by mixing sago starch with water, having machines rub the paste into grains, and then drying them by machine. The heat cooks some of the starch and gelatinizes it, making it dissolve more easily than just regular Sago Starch.
They end up about 86 % starch, 13% moisture.
The pearls can be whitened commercially using chlorinated lime in solution. A lower-grade is also available, that is browner, more unevenly sized grains, and not having a lustre to it.
Pearls from Sumatra are considered the best.
Cooking Tips
Sago Pearls dissolve only somewhat in cold water. The water needs to be hot. Boil for about 1 hour until they are translucent, or if you want a chewy texture, add them to a liquid dish in the last 10 minutes of cooking.
In the Philippines, drinks are made from cooked Sago Pearls, flavoured and coloured, with milk or cold water added, and some kind of sweetener such as raw sugar. You put a few tablespoons of the cooked pearls in a glass, add the milk or water, sweeten, add any colouring or additional flavourings, and stir. You can add crushed ice.
Substitutes
Tapioca Pearls.