The invention relates to a process for dehydrating a water- containing medium, said medium being a pressurized gas having a pressure of at least 0.5 MPa, said process comprising: - contacting the water-containing medium with a dry ionic liquid choline salt to dehydrate the water-containing medium; and - separating a dehydrated medium from the hydrated ionic liquid choline salt. Ionic liquid choline salts offer the advantage that they can be regenerated very easily as they are surprisingly heat-stable. Furthermore, these liquid choline salts offer the advantage that they are non-toxic and largely inert. Thus, these ionic liquid choline salts can suitably be used to dehydrate water-containing media that are subsequently employed in the production of foodstuffs, beverages, nutritional formulations, pharmaceutical preparations etc.