We use the optical birefringence of 1,2-dipalmitoylphosphatidycholine bilayers (DPPC) in the gel (L β′ ) phase to study recombination dynamics of topological defects. The birefringence of anisotropic thin films, such as the L β′ phase of DPPC bilayers, is related to their molecular polarizability, different on the heads and the acyl chains. When the sample is cooled down into the L β′ phase, a period of rapid recombination (taking place over a few seconds) is followed by slow dynamics with metastable states existing in excess of several minutes. After this, either another metastable state or a truly stable state remains where no further change is observed, although a spatially non-uniform distribution of the orientation of the birefringence remains. We compare our results with a model for the free energy and the dynamics of the lipid bilayer in the gel state, finding good qualitative agreement.