The present invention relates to a culture medium, which can be used especially in in vitro culture and in bacteriology. This medium consists of a solid gel containing 0 to 80% by weight of water optionally supplemented with nutritive elements, which is preformed, especially by moulding, to the shapes of the culture container, and which is capable of forming, without heating, by addition of a predetermined quantity of water, a continuous gel preserving its initial shape. Application: Multiplication of plants, bacteriology.
