PURPOSE: To store grains for emergency simply and in a sufficiently dried state without causing deterioration of qualities such as heat denaturation, etc., by bringing grains into contact with a substance having high osmotic pressure to dehydrate the grains without using heat, adjusting a water content to ≤a specific value and storing the grains for emergency.

CONSTITUTION: For example, grains are brought through semipermeable membranes (e.g. cellophane paper, etc.) 2 into contact with a substance (e.g. sucrose, etc.) 3 having high osmotic pressure by the use of a dehydrating sheet 1, etc., wherein the substance having high osmotic pressure is laid between the semipermeable membranes, dehydrated without heat, adjusted to ≤about 9%, preferably 4W6% water content and stored for emergency.