Experiments were performed with individual saskatoon berries under controlled conditions to determine freezing characteristics. The air velocity, the temperature of the freezing air, and their interaction were statistically significant (P > 0.0001) on the time for saskatoon berry to drop in temperature from 0 to -10C. A 2.2 kW (3 hp) prototype freezer was designed and constructed on a saskatoon farm, and tested in the 1999 and 2000 harvest years. At the beginning of a harvest day, the temperature of the prototype freezer was below -20C, the initial temperature of berries entering the chamber was approximately 5C, and the berries reached a temperature of -10C within 1 h. At the end of a harvest day, the chamber temperature had risen to -12C, the initial temperature of the berries was between 15 and 20C, and the time for the berries to reach -10C was greater than 4 h. (Abstract shortened by UMI.)