Polysaccharide aerogels are gaining wide interest due to their open pore nanostructure, high surface area, biodegradability and biocompatibility. By application as chemical adsorbents and gas or liquid purifiers–the sorption properties are of crucial importance. The aim of the work was to determine the level of water content in potato starch aerogel at which saturation of the sorption sites is complete. Potato starch aerogels hydrated from gas phase were subjected to low field nuclear magnetic resonance (LF NMR) analyses. It was stated that starch aerogels reveal higher sorption capacity than native and modified starch as well as cereal extrudates. By low hydration they are characterised by one component of spinlattice relaxation time T1. It decreases with the increase of hydration due to the increase of the order of the system. In these conditions, only bound water is present in the aerogel. Above the limit value of hydration equal to 0.1 g/g, describing the saturation state of all sorption sites, two components of spin-lattice relaxation time start to appear. The first component of spin-lattice relaxation time T11, describing bound water fraction, is constant, independently of the amount of water in the system. The second component of spin-lattice relaxation time T1s, describing bulk water fraction, rapidly grew as hydration increased.