This disclosure relates to a scale-down system (10) for freezing and thawing aqueous liquid mixtures of thermo sensitive substances comprising a small first container (100), and a holder for holding the first container and an insulator (300), wherein the holder is outwardly surrounded by the insulator such that the insulator insulates at least 50% of the holder and such that the heat transfer between the first container and a second, larger container (20) is equivalent. The active heat transfer surface of the scale-down container can be attached to a heat exchanger having a precise heat transfer coefficient. The first container may have a square cross-section, a triangular or a trapezoidal cross-section.
