The changes in milk composition from the turn of the century to the present date are reviewed and the difficulties that the changes may have given to manufacturers are discussed. Butter manufacture is not affected by changes in milk compositional quality, although the spreadability of butter follows the seasonal changes in the hardness of milk fat. The legal requirements for the composition of cheese are set at levels that have not given any difficulty but the yield of cheese has suffered due to the progressive deterioration in the casein content of milk. There are some specific problems related to the operation of the European Economic Community milk subsidies, although these are more administrative and bureaucratic difficulties than compositional problems. It is concluded that technological advance can cope with any likely change in compositional variability, provided that legislation is not introduced to ensure the perpetuation of traditional methods.