The process is older than the equipment by several centuries.
Freeze drying was a preservation technique long before anyone described the physics.
On the high Andean plateau, potatoes were left out overnight to freeze, then exposed to intense daytime sun at low atmospheric pressure — altitude doing the work a vacuum pump does now. The result, chuño, kept for years and is still made. Freezing, low pressure, sublimation: the same three steps, without the machine.
The process was formalised in the lab well before it was industrialised.
Early twentieth-century work established lyophilization as a laboratory technique for preserving biological material. The word itself — from the Greek for "solvent-loving," describing how readily the porous product takes water back — comes from this period.
Two applications, a decade apart, that built the industry.
The Second World War created urgent demand for blood plasma that could be shipped and stored without refrigeration and reconstituted in the field. That programme drove the first genuinely industrial-scale freeze drying and much of the engineering that followed.
Post-war, the same equipment found a commercial market in instant coffee, where freeze drying preserved aroma compounds that spray drying destroyed. Pharmaceuticals, space and military rations, and eventually consumer food followed.
A useful thing to know about the market you are entering.
Pharmaceutical lyophilization and food freeze drying have developed largely in parallel — different regulatory worlds, different vocabulary, different equipment traditions, the same physics. Meanwhile the food side has grown quickly on pet nutrition, freeze-dried candy and the raw-feeding market, and much of the current equipment demand comes from operators scaling out of home units.
No single inventor. Pre-Columbian Andean cultures produced chuño using freezing overnight and low-pressure daytime sublimation at altitude. The laboratory process was formalised in the early twentieth century, and industrial scale arrived with the Second World War blood plasma programme.
Blood plasma for the Second World War drove the first industrial scale. The first large commercial consumer application was instant coffee, where freeze drying preserved aroma compounds that spray drying destroyed.