U.S. Patent #1,773,079: Freezing; Subsequent thawing; Cooling the materials not being transported through or in the apparatus with or without shaping, e.g. in the form of powder, granules or flakes with packages or with shaping in the form of blocks or portions.
This 1924 patent from Clarence Birdseye is the first documentation of the “flash freezing” process originally used by Labrador anglers to quickly freeze fish to preserve freshness.