In order to control the release of hydrogen from POWERPASTE effectively, it is particularly important to ensure precise dosing of the reactants, thorough mixing of the magnesium hydride and water, and a rapid hydrolysis reaction of the magnesium hydride powder despite the formation of Mg(OH)2 surface layers. These requirements are best met technically in the form of a paste-like substance. To achieve a homogeneous paste-like mass with defined flow properties, the magnesium hydride powder is ground in a stirred ball mill together with a carboxylic acid ester and small amounts of a metal salt to form a paste-like substance, with the magnesium hydride solid content being approximately 70 vol.%.