Summary: During World War II, Charles H. Best utilized Charles R. Drew's plasma isolation and drying technique to lead Canada's initiative to provide dried serum as a means of primary resuscitation for British casualties on the frontlines. Serum was likely utilized over plasma for its volume expansion properties without the risk of clotting during prolonged storage. We reconstituted dried serum from 1943 and discovered intact albumin, as well as anti‐thrombin, plasminogen, protein C and protein S activity. Proteomic analysis identified 71 proteins, most prominent being albumin, and positive for hepatitis B by serological testing. Transmission of blood‐borne diseases ended the programme, until modern advances in testing and pathogen reduction revived this technology. We tested the latest iteration of Canadian freeze‐dried plasma (FDP), which was stored for 4 years, and demonstrated that its clotting capacity remained equivalent to fresh frozen plasma. We recommend that FDP is a strong alternative to contemporary prehospital resuscitation fluids (e.g. normal saline/lactated Ringer's) in managing prehospital haemorrhage where whole blood is unavailable. [ABSTRACT FROM AUTHOR]