Tapioca flour is a starch extracted from the root of the tropical cassava plant (also called manihot or manioc or yucca). This is a tall slender plant, which has poinsettia type leaves. It can attain heights of ten to sixteen feet.
The root tubers grow in clusters and are tapered in shape, like giant sweet potatoes, twelve to twenty inches long; they sometime weigh as much as thirty pounds.
When fully grown, the roots are harvested and sent to modern mills near the plantation. They are washed and peeled by tumbling in water sprays, then ground to a fine pulp. The liquid, which now contains the starch, is drained off.
To separate and purify it, repeated washings and settlings form the starch into a moist cake. This is further dried and pulverized into a tapioca flour.