Flavour SU(3) symmetry-breaking as a constraint on the strange quark condensate

While the light quark vacuum condensate $\langle \bar{q} q\rangle$ is well-understood and known to good precision, the strange quark vacuum condensate $\langle \bar{s} s\rangle$ is not as well determined. Using the renormalization-group invariant strange quark mass ratio $r_m = m_s/m_q$, as well as properties of pions and kaons, we develop a simple constraint on a dimensionless PCAC deviation parameter $r_p$ and the quark condensate ratio $r_c = \langle \bar{s}s\rangle/\langle \bar{u}u\rangle$ to ensure self-consistency between the two parameters, and to tighten the bounds on $r_p$. We compare predictions in the literature against this constraint.