  We reconsider the problem of calculating the vacuum free energy (density) of
QCD and the shift of the quark condensates in the presence of a uniform
background magnetic field using two-and-three-flavor chiral perturbation theory
($\chi$PT). Using the free energy, we calculate the degenerate, light quark
condensates in the two-flavor case and the up, down and strange quark
condensates in the three-flavor case. We also use the vacuum free energy to
calculate the (renormalized) magnetization of the QCD vacuum, which shows that
it is paramagnetic. We find that the three-flavor light-quark condensates and
(renormalized) magnetization are improvements on the two-flavor results. We
also find that the average light quark condensate is in agreement with the
lattice up to $eB=0.2 {\rm\ GeV^{2}}$, and the (renormalized) magnetization is
in agreement up to $eB=0.3 {\rm\ GeV^{2}}$, while three-flavor $\chi$PT, which
gives a non-zero shift in the difference between the light quark condensates
unlike two-flavor $\chi$PT, underestimates the difference compared to lattice
QCD.
