Method for Making Soluble Starch from Sweet Potato

Soluble starch is a white or pale yellow powder, odorless and tasteless, insoluble in cold water, but it becomes a transparent solution in hot water and does not gel after cooling. Generally, starch from rice, corn, millet, or potato can all be used to make soluble starch, but soluble starch made from sweet potato starch is of the best quality. Sweet potato starch grains are relatively coarse, and the film wrapping the outside tends to rupture during hydrolysis, making it easy to dry. The processing procedure is:

Take a certain amount of sweet potato starch, sift it through an 80-mesh fine sieve, place it in a large vat, add 8%-9% hydrochloric acid, stir the solution into a thin paste, and soak it at 40-45 degrees Celsius for 24 hours, or leave it at room temperature for 6-7 days. Stir once every 2 hours. After soaking is complete, siphon off the upper clear liquid in the vat, then wash with water several times while stirring continuously until no chloride ions remain. Then drain, dehydrate, and dry, and finally grind fine with a stone mill and pass through a sieve with 100-120 mesh openings; this is soluble starch.