The tendency of specific two-phase liquid-liquid systems to emulsify makes proper pilot scale process development extremely important for successful process scale-up. This paper will focus on a case study of a polymer solution – water mixture that exhibited strong emulsification tendencies and the challenges associated with piloting and scale-up. Its behaviors and unique features will be compared to a system with low emulsification tendency. Efforts to measure liquid-liquid mixture properties and correlate them to input process conditions and equipment design will be detailed. A brief description of ongoing process improvement efforts will be included.