Although a number of different processes are used to prepare factor VIII concentrates from human plasma the recovery of coagulant activity is almost always very low.A number of loss mechanisms can be identified and these tend to be associated with large‐scale manufacture, where pools of hundreds or thousands of litres of plasma are processed. Many of the procedures which result in loss are common to virtually all of the different manufacturing processes and considerable improvement in yield is possible, particularly if attention is given to careful process engineering design.For the preparation of an intermediate‐purity concentrate the most important points are considered to be:• Provision of a good quality plasma feedstock.• Rapid processing, with no delays from initiation of plasma thawing to freezing of the final concentrate.• Continuous thawing of plasma to allow rapid thawing with precise control of temperature.• Effective centrifugation for cryoprecipitate collection.• The use of low shear agitators and careful control of pH adjustment.• In‐process control of ionised calcium concentration.Further processing to prepare concentrates of increased purity also results in significant loss of factor VIII and new higher yielding methods are needed if high