During acrylic acid (AA) storage, a quality loss occurs due to the formation of by-products such as diacrylic acid (DiAA), triacrylic acid (TriAA), and higher oligomers. This problem intensifies in the presence of water since the formation rate of oligomers increases and further by-products such as 3-hydroxypropionic acid (3-HPA) and 3-hydroxydiacrylic acid (3-HDiAA) are formed. However, water is often essential during storage and transport to raise the flash point or reduce the melting point. In this work, the formation kinetics are investigated for all mentioned components in pure and aqueous AA. The formation mechanisms of 3-HPA and 3-HDiAA are assumed as acid-catalyzed ester hydrolyses of DiAA or TriAA. The introduced reactions are modeled with the measured kinetic data in order to confirm the proposed reactions.