  We derive a simple relation between strangeness neutrality and
baryon-strangeness correlations. In heavy-ion collisions, the former is a
consequence of quark number conservation of the strong interactions while the
latter are sensitive probes of the character of QCD matter. This relation
allows us to directly extract baryon-strangeness correlations from the
strangeness chemical potential at strangeness neutrality. The explicit
calculations are performed within a low energy theory of QCD with 2+1 dynamical
quark flavors at finite temperature and density. Non-perturbative quark and
hadron fluctuations are taken into account within the functional
renormalization group. The results show the pronounced sensitivity of
baryon-strangeness correlations on the QCD phase transition and the crucial
role that strangeness neutrality plays for this observable.
