Starch‐gel electrophoresis at high resolution has shown that qualitative and quantitative differences exist between the patterns of gliadins and of water‐soluble proteins from several wheat varieties. Four of the major gliadin proteins have been recovered from starchgels and found to give single bands when re‐run, suggesting that they are probably not formed by association reactions. Of other cereals examined, rye prolamin showed the closest relationship to gliadin. It is suggested that observed differences may play a part in explaining variability in baking quality, but that other factors are probably involved. The effects of air classification, chlorination, fat, mechanical action, and separation of flour by solvent flotation, upon the electrophoretic patterns have been examined. Some of the flour proteins appear to survive the baking process without denaturation.