The development of low-cost materials and efficient methods for the fractionation of water and ethanol in binary mixtures is of great interest for food processing and biofuels production. Herein, we report a systematic study of a series of linear and branched starch-based biopolymers along with their modified forms via cross-linking with epichlorohydrin (EPI) at variable EPI composition. The fractionation properties of these adsorbent materials were studied in binary ethanol–water solutions and compared against those of neat solvents. 1H NMR spectroscopy was used to assess the binary solvent composition for the study of isotherms for the respective solvent components. The monolayer adsorption capacity (Qm) for starch and its cross-linked forms varied from 0.01 to 2.70 g·g–1 for water and ethanol in binary mixtures according to the Sips isotherm model. The fractionation selectivity [Rselectivity; Qm(W)/Qm(E)] of starch-EPI adsorbents for water (W) and ethanol (E) in binary mixtures ranges from 3.8 to 80. A...