Drying of food and herbs is one of the oldest preservation methods of humanity.
Freeze-drying was first carried out, as K. H. Neumann wrote in his book Grundriß
der Gefriertrocknung, 1954, by Altmann, who freeze-dried parts of organs in 1890. In
1932, Gersh designed an effective vacuum plant for freeze-drying of histological
preparations with the help of the diffusion pump just invented by Gaede at that time.