The enzyme catalyzed polycondensation of 1,3-propanediol and 9-((Z)-non-3-enyl)-10-octylnonadecane diacid was carried out in a bubble column reactor. A conversion of 94% was achieved within 50h. A chemometric model was developed using infrared spectra collected via FT-IR combined with attenuated total reflectance probe. Root mean square errors of cross validation of the model for conversion and molecular weight were 2.14% and 319gmol-1, respectively.