Methyl esters from vegetable oils (biodiesel) are very attractive as alternative fuels for combustion in direct injection compression-ignition (diesel) engines. Biodiesel fuels have low-temperature flow properties that limit utilization during cooler weather in moderate temperature climates. Although winterization reduces the cloud point (CP) of methyl soyate from 0 to -2O°C, liquid product yields were relatively low (0.30-0.33 g/g). Winterization of methyl soyate-cold flow improver mixtures decreased CP by -11°C and increased yields to 0.80-0.87 g/g. Winterization of methyl soyate from hexane and isopropanol solvents gave similar results. Differential scanning calorimetry (DSC) analyses showed that nucleation mechanisms of methyl esters were significantly affected by winterization.