We present the results of a simple experiment suitable for the undergraduate laboratory in which the onset of turbidity when an aniseed‐based liquor is diluted with water is observed. The optical transmission shows the behavior typical of the order parameter in a second‐order phase transition. The changes in the transmission are due to the precipitation of terpenes and the amount of precipitated terpenes also shows critical behavior of the formn=k′(c−cc)y, wherecis the fraction of water in the solution. The critical exponent is determined to bey=1.01±0.06.