Starch thinning process

A multi-stage process for the enzymatic thinning of starch employing the enzyme .alpha.-amylase which comprises forming an aqueous starch suspension, subjecting said aqueous starch suspension to a first stage thinning operation in the presence of added .alpha.-amylase, said first stage thinning operation being carried out at an initial temperature in the range 100.degree.-110.degree. C. for at least 3 minutes, and further heating the suspension at a final higher temperature of at least about 140.degree. C. for at least about 3 minutes, said first stage thinning operation being carried out at a pressure sufficient to maintain the aqueous starch suspension being thinned in the liquid phase, thereupon subjecting the resulting enzymatically thinned starch suspension to atmospheric flashing to reduce the pressure of said resulting enzymatically thinned starch suspension to atmospheric pressure and to effect cooling thereof and subjecting the resulting treated starch suspension to a second stage thinning operation carried out at atmospheric pressure and at a temperature in the range 90.degree.-100.degree. C. in the presence of additional added .alpha.-amylase for at least 30 minutes to produce an aqueous thinned starch product.