Ternary crystalline, dispersions of 10 wt % sodium stearate (NaSt) in mixtures of water and propylene glycol (PG) have been investigated at the atomic, molecular, and microscopic levels. Two lamellar crystalline structures, alpha -NaSt and beta -NaSt, have been determined by X-ray diffraction. Compared with beta -NaSt, alpha -NaSt exhibits a larger bilayer thickness, a more ordered packing of hydrocarbon chains, and dissolves at a lower temperature in the PG/H2O mixture. A transformation from beta -NaSt to alpha -NaSt is observed upon aging in a PG concentration range of 60-95 wt % in mixtures of H2O and PG. The aging transformation progresses faster and to a greater extent as the PG content increases. Additionally, the fibrous crystallites of alpha -NaSt are more bundled and oriented compared to those of beta -NaSt, as revealed by two-dimensional SAXS (small-angle X-ray scattering) and cryo-SEM (cryogenic scanning electron microscopy). The conformation and mobility of the alkane chains in a-NaSt and beta -NaSt have been further studied by solid-state C-13 CP MAS (crosspolarization magic-angle spinning) NMR. A greater percentage of trans chain conformation is found in a-NaSt, and the rigidity of the chains is higher. A stronger association of PG with beta -NaSt crystals than with alpha -NaSt crystals is also indicated by the appearance of the PG carbon resonances in the solid-state NMR spectrum.