KW in addition to the -40°C liquid bath freezer, proposes an alternative solution, satisfying however the technical advices and the normative in place, on the freezing time of the plasma bags. The adapted principal of thermal exchange, in this case, does not use a cold bath at - 40°C , but -75 /- 80 °C surfaces, with which the bags are in direct contact. The plasma bags, to be frozen, are immersed, vertically, in wells in which the walls are at least 75°C -80°C. The geometry of the wells is conical, to simplify extraction and formation of the solid bag, without any impediment for the increase in volume which happens when there is a passing in state from liquid to solid. RAPIDITY FREEZING the bag is in contact with the surfaces of the wells and intense extraction of thermal energy is obtained in this manner, minimizing in this way the freezing time: < 45 for 24 (450 ml.) nominal standard bags, with a net content of plasma of at least 230 cc. and an initial temperature between + 25°C and + 30°C KW has undertaken tests with bags with a mass of 260 gr. each.