However, there are not yet many studies utilising THz-TDS to investigate the crystallisation process in solutions. May and Taday employed terahertz spectroscopy in ATR configuration and monitored the crystallisation of sucrose in confectionary products . The results clearly showed the transition from sugar solution to a solid glassy and then crystalline state. this method and successfully proved the existence of intermediate hydrate states in the crystallisation of L-(+)-tartaric acid during the evaporation of water from aqueous solutions of tartaric acid solutions . Terahertz spectra were acquired over a period of 60 h while water evaporated and three stages of crystallisation were discernible. At the beginning, the spectra of the solution phase were featureless. In the nucleation stage, the absorption decreased as a result of the reduction in water concentration due to evaporation. In some experiments discontinuous increases in absorption were observed which were attributed to water being released when the hydrated states transformed to the final crystals. A feature was spotted at approximately 750 GHz that was hypothesised to result from the vibration of water molecules surrounding the fragments of solvent molecules. The final observed stage was the crystalline phase displaying a dominant absorption feature at 1.1 THz. These three stages were assumed to be happening inhomogeneously throughout the probed volume.