The family practice is:
Wash the sweet potato, cut it into thin shreds, put it into a basin containing water, and stir it well with your hands to wash down the starch on the surface of the potato shreds.
If there are more sweet potato shreds, put them in several times.
Scoop up the potato shreds through a strainer and leave them for a while to wait for the starch to settle.
Then slowly pour the pot, pour out the water in the pot, and then put in the water to stir and precipitate, and circulate a few times. The starch is clean and pure white.
Dry the wet starch, clean and pure white starch is ready.
Don't throw away the shredded potatoes, they can still be used for cooking.
The industrial practice is to break the sweet potatoes with well to get more starch.