the invention relates to a method for producing effervescent granules , in which the reaction partners edible , organic acid components and alkaline effervescent components separating carbon dioxide are reacted with each other in a vacuum under the effect of gas in a container that can be evacuated . the container is evacuated to a first vacuum value within a vacuum range of 200 - 900 mbar , whereupon the pressure inside the container is increased to a second vacuum value as a result of the gases produced during the reaction . the steps are cyclically repeated while the reaction continues . a maximum number of cycles , a maximum reaction time , and optionally , a maximum load for the stirring apparatus are defined before the reaction begins , and the reaction is terminated after reaching the first of the maximums . in an alternative embodiment , the invention also relates to a method for improving the shelf life of effervescent granules by a treatment with carbon dioxide during and / or following the production of the effervescent granules , and effervescent particles treated in this manner .