  Confinement in $SU(N_{\rm DC})$ Yang-Mills theories is known to proceed
through first-order phase transition. The wall velocity is bounded by $v_w
\lesssim 10^{-6}$ due to the needed time for the substantial latent heat
released during the phase transition to dissipate through Hubble expansion.
Quarks much heavier than the confinement scale can be introduced without
changing the confinement dynamics. After they freeze-out, heavy quarks are
squeezed into pockets of the deconfined phase until they completely annihilate
with anti-quarks. We calculate the dark baryon abundance surviving
annihilation, due to bound-state formation occurring both in the bulk and - for
the first time - at the boundary. We find that dark baryons can be dark matter
with a mass up to $10^3~\rm TeV$. We study indirect and direct detection, CMB
and BBN probes, assuming portals to Higgs and neutrinos.
