In the past it has been common practice to try to stop hydration, or at least to slow it down considerably by using a retarder, often in the form of sugar. This practice has a number of disadvantages, not the least being the time limitation and the addition of the retarding agent, which may be most undesirable in the light of subsequent laboratory work. Ideally the sample should be received at the laboratory in exactly the same condition as it was at the point of sampling irrespective of whether the intervening period be hours or days. As water is one of the active constituents of concrete, freezing was considered as a method of restricting hydration. For practical application of the technique a simple cheap storage container that could be used repetitively was produced. It comprised a timber box with an expanded polystyrene lining 6 inches thick on all surfaces, this in turn being protected by a timber inner lining. A metal drum was placed inside the insulated container and the area between the lining of the box and the drum filled with solid carbon dioxide. To determine whether the quality of the concrete was affected by the freezing treatment and storage, a comparison was made between the setting times and compressive strengths of two halves of a concrete mix, the control half being treated normally for preparing test specimens and the remainder being stored in a frozen condition for 12 days before specimens were made. A comparison of setting times measured by penetrometer showed that little difference between the control sample and the sample from the concrete stored at low temperature. The value for the average compressive strength after curing for 28 days for the frozen sample was slightly higher. These results indicate that no serious harmful effects are produced when fresh concrete is stored in this manner but that considerable care must be taken when defrosting to prevent the loss of moisture.