Method for melting frozen, water-containing products in a mixer

Method of thawing pieces of ice which contain blood plasma or blood plasma products and water, which comprises introducing said pieces of ice into a horizontal mixer, said horizontal mixer comprising at least one stirrer whose axis of rotation is arranged horizontally, heating the horizontal mixer and at the same time mixing the contents of the mixer to maintain the temperature of the contents of the mixer at a temperature which is less than 10° C. above the melting point of said pieces of ice, whereby said pieces of ice are melted to form a liquid phase and during such melting, floating pieces of said pieces of ice which have not yet been melted are continually submerged in the liquefied phase and mixed with it.