A process for fractionating an esterified cellulose ether comprising groups of the formula C(O) R COOH wherein R is a divalent hydrocarbon group comprises the steps of a) blending the esterified cellulose ether comprising groups of the formula C(O) R COOH with an aqueous liquid and setting the temperature of the resulting blend to less than 10 °C to dissolve a portion of the esterified cellulose ether in the aqueous liquid b) separating the non dissolved portion of the esterified cellulose ether from the remainder of the blend and c) recovering or disposing of the esterified cellulose ether that is dissolved in the aqueous liquid.
