I outline a new production mechanism for dark matter (DM) dubbed "recycling".
In recycling, multiple DM candidates reside, as massless particles, in a dark sector which is initially in kinetic equilibrium with the Standard Model. The dark sector undergoes a first order phase transition (FOPT), and the DM candidates acquire a mass much larger than their temperature and therefore get trapped in the false vacuum. The rate of leakage of dark sector particles into the true vacuum is suppressed enough that eventually (some of or even all of) the pockets of false vacuum collapse into primordial black holes (PBHs). During Hawking evaporation, PBHs reproduce (recycle) the DM candidates that initially collapsed into them. The DM particles emitted by PBHs are ultra-heavy (∼10^{12} GeV), due to being materialized in the true vacuum, and are sparse enough to be able to explain the observed abundance of DM today without overclosing it.