The Cantor alloy originates from a set of experiments conducted on combinations of equiatomic CrMnFeCoNi-Nb/Ge/Cu/Ti/V systems prepared by non-equilibrium processing.However,the use of non-equilibrium processing may provide only a conditional basis of compositional ratios. Consequently, observed compositions may be stable phases but metastable under a different set of conditions regarding composition, temperature, and cooling rate. True equilibrium processing requires cooling rates that are complementary to a geological time scale.This is unrealistic, but the slower the cooling rate, the closer one approaches equilibrium conditions. In this work, we describe a method applicable to HEAs, where controlled processing conditions decide the most probable and stable composition. We demonstrate this by cooling an equiatomic CrMnFeCoNiCu from the melt over a period of 3 days, which results in large Cr-rich precipitates and a nearly Cr-free matrix. From this juncture, we argue that the most stable composition lies in the MnFeCoNiCu system rather than the CrMnFeCoNi system.