A method for producing a biologically active, microorganism-containing aqueous solution or suspension including steps of the provision of water, the optional addition of a fine-grained mineral or organic material to the water and mixing of this materials into the water in order to obtain a suspension, the addition of compost to the suspension, and resting the suspension in an airtight environment for at least one week at a temperature of less than 15° C. This method allows the production of a biologically active, microorganism-containing solution or suspension which can be added to natural bodies of water or to soil, and may be used for external and internal application in humans and animals.