In this study, a homologous series of calcium stearoyl lactylates (CSLs) with adjustable phase transition temperature were synthesized as solid–liquid phase change materials (PCMs) by esterification between stearic acid (SA) and lactic acid (LA), combining with the self‐esterification of LA, and neutralization with calcium hydroxide (Ca(OH)2). The chemical structures of CSLs were confirmed by Fourier transform infrared spectroscopy (FT‐IR) and 1H nuclear magnetic resonance spectrum (1H NMR). X‐ray diffraction (XRD) was applied to study the crystalline structure of solid–liquid PCMs. Differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA) were carried out to determine the phase change properties and thermal stability of prepared CSLs. Research results show that calcium ions (Ca2+) have positive effects on improving form stability of synthesized PCMs. The melting temperatures in the range of 40.45°C–25.47°C could be tailored by varying the molar ratio of SA to LA from 1:1 to 1:4. The thermal storage capabilities reach about 53% with the latent heat of fusion in the range of 84.5–55.50 J/g. The PCMs show acceptable thermal reliability and reusability after thermal cycles for 100 times. Suitable phase transition temperatures make CSLs potential for thermal comfort, and the mechanism of temperature regulation would provide reference for design of more PCMs used in different situations. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13136, 2019