  We study cosmological perturbations arising from thermal fluctuations in the
big-bounce cosmology in the Einstein-Cartan-Sciama-Kibble theory of gravity. We
show that such perturbations cannot have a scale-invariant spectrum if
fermionic matter minimally coupled to the torsion tensor is macroscopically
averaged as a spin fluid, but have a scale-invariant spectrum if the Dirac form
of the spin tensor of the fermionic matter is used.
