A starch thinning and etherification process is provided comprising the steps of (a) mixing a starch substrate with a thinning agent, an alkalizing agent and an etherification agent; (b) drying the mixture of step (a); and (c) allowing the dried mixture to react with the etherification agent, wherein: the thinning agent consists of one or more hypochlorites; step (a) is carried out at an alkaline pH and does not involve any artificial heating; and step (b) is carried out before the mixture of step (a) reaches the starch substrate's gelatinisation temperature.