PURPOSE: To obtain starch granules soluble in cold water, capable of gelling and readily gelatinizing without the need for heating or chemical treatments, by treatment of starch granules using mechanical means with functions such as impacting or collapsing.

CONSTITUTION: Starch granules (e.g., rice, maize, potato or arrowroot) are treated by mechanical means (e.g., ball mill, rod mill, sandblast, kneader, mortar or stone mill) having functions such as impacting, collapsing, friction or shearing, thus obtaining the objective starch granules capable of at least partially converting to paste and dissolving in cold water. For the starting starch granular, raw starch granules or starch granules with the hydroxy groups chemically modified are preferably used and recommended to be treated by mechanical means in a blended state with pigments. The resultant granules normally retain such shape as to be similar in the grain size to that of the original granules even after dispersing and partly dissolving in cold water.