The present invention addresses the problem of providing modified gluten capable of imparting excellent freezing tolerance to a bread dough and a method for manufacturing the modified gluten. Provided is a method for manufacturing modified gluten which comprises a step for heating a solution containing gluten together with an organic acid having two or more carbonyl groups per molecule, said organic acid being used in an amount of 1 part by weight or more per 100 parts by weight of gluten, at 70