A system and method for producing bisphenol-A (BPA) is provided. In particular, the present invention provides a system and method of producing bisphenol-A wherein the phase equilibrium behavior of a feed solution to a crystallizer is selectively controlled and adjusted to provide desired results. This provides a powerful tool, whereby certain operating conditions or variables of the bisphenol-A process can be selectively adjusted to generate desired phase equilibrium behavior. In general, bisphenol-A is produced from a reaction of phenol and acetone, forming a product solution including phenol, bisphenol-A, isomers of bisphenol-A, unreacted reactants and by-products. A solvent is provided in the product solution and the amount and composition of solvent in the product solution are selectively controlled to adjust the composition of the product solution fed to a crystallizer such that either crystalline bisphenol-A, or an adduct of bisphenol-A and phenol is crystallized from the product solution. Thus, a solvent is used to selectively control the phase behavior of the system. The solvent is a pseudo component and may be comprised of a single component or may be comprised of a solvent mixture of two or more solvents each exhibiting certain phase behavior in the system.