A method of recovering polyhydroxyalkanoates (PHA) from mixed culture PHA-containing biomass, comprising: - determining an isothermal extraction trend as a function of temperature; - empirically modelling the isothermal extraction trend to a sigmoid function (f 15 ) that describes the trend of increased extent of extracted polymer with temperature after 15 minutes according to: f 15 = 1 1 + e − k 15 T − T H where f 15 = fraction of extractable polymer after 15 minutes as a function of Temperature (T); k 15 = 15 minute extraction rate temperature coefficient; T H = the temperature for f 15 equal to 0.50; - determining, from the sigmoid function (f 15 ), a lower limiting temperature TL 15 and an upper limiting temperature TU 15 , wherein the lower limiting temperature TL 15 is a temperature below which negligible extraction will occur within 15 minutes and the upper limiting temperature TU 15 is a temperature where significant extraction will occur within 15 minutes; - directing the biomass into a reactor; - mixing a solvent with the biomass in the reactor; - heating the solvent and the biomass in the reactor; - extracting the PHA from the PHA-containing biomass by dissolving the PHA in the solvent to form a PHA-rich solvent; - maintaining the PHA solvent at a temperature between the lower limiting temperature TL 15 and the upper limiting temperature T U15 ; - transferring the PHA-rich solvent from the reactor to a PHA separator where the PHA is separated from the PHA-rich solvent; - while transferring the PHA-rich solvent to the PHA separator, maintaining the PHA-rich solvent at a temperature that prevents the PHA-rich solvent from assuming a gelation state; - cooling the PHA-rich solvent to form a PHA-rich solvent gel; and - mechanically pressing the PHA-rich solvent gel at the PHA separator location and causing the solvent to be removed from the PHA-rich solvent gel. - determining an isothermal extraction trend as a function of temperature; - empirically modelling the isothermal extraction trend to a sigmoid function (f 15 ) that describes the trend of increased extent of extracted polymer with temperature after 15 minutes according to: f 15 = 1 1 + e − k 15 T − T H where f 15 = fraction of extractable polymer after 15 minutes as a function of Temperature (T); k 15 = 15 minute extraction rate temperature coefficient; T H = the temperature for f 15 equal to 0.50; f 15 = fraction of extractable polymer after 15 minutes as a function of Temperature (T); k 15 = 15 minute extraction rate temperature coefficient; T H = the temperature for f 15 equal to 0.50; - determining, from the sigmoid function (f 15 ), a lower limiting temperature TL 15 and an upper limiting temperature TU 15 , wherein the lower limiting temperature TL 15 is a temperature below which negligible extraction will occur within 15 minutes and the upper limiting temperature TU 15 is a temperature where significant extraction will occur within 15 minutes; - directing the biomass into a reactor; - mixing a solvent with the biomass in the reactor; - heating the solvent and the biomass in the reactor; - extracting the PHA from the PHA-containing biomass by dissolving the PHA in the solvent to form a PHA-rich solvent; - maintaining the PHA solvent at a temperature between the lower limiting temperature TL 15 and the upper limiting temperature T U15 ; - transferring the PHA-rich solvent from the reactor to a PHA separator where the PHA is separated from the PHA-rich solvent; - while transferring the PHA-rich solvent to the PHA separator, maintaining the PHA-rich solvent at a temperature that prevents the PHA-rich solvent from assuming a gelation state; - cooling the PHA-rich solvent to form a PHA-rich solvent gel; and - mechanically pressing the PHA-rich solvent gel at the PHA separator location and causing the solvent to be removed from the PHA-rich solvent gel. <EOS>