A bioderived plasticizer for biopolymers includes a compatibilizing unit and a polyester plasticizing unit. The plasticizer improves the flexibility of biopolymers while not adversely affecting the modulus of the biopolymer. The compatibilizing unit renders the plasticizer more miscible with the desired base biopolymer, and may increase crystallization and includes a lower alkyl (C3 to C7) organic acid including enantiomeric isomers of the base polymer. The polyester plasticizing unit is formed from monomers comprising a multifunctional alcohol and an aliphatic anhydride or its equivalent dicarboxylic acid and ester derivatives. The polyester plasticizing unit may optionally include one or more difunctional alcohols in combination with the multifunctional alcohol. The resulting bioderived plasticizer lowers glass transition temperature (Tg), can improve brittleness, may increases heat deflection temperature and improves melt viscosity.