The electrical properties and hydrogen permeation flux behavior of the all-ceramic protonic/electronic conductor composite BaCe0.2Zr0.7Y0.1O3-δ/Sr0.95Ti0.9Nb0.1O3-δ (BCZY27/STN95: BS27) are evaluated. Conductivity and hydrogen permeability are examined as a function of phase volume ratios. Total conductivities of 0.01 – 0.06 S•cm-1 are obtained in moist (+ 1 % H2O) H2/inert gas from 600 – 800 °C for 50 volume % STN95. With increasing STN95 content (60 and 70 volume %), conductivity increases by 5 – 10 times, but displays a semiconductor-type dependence, even at 70 volume % STN95. The conductivity is modeled with an effective medium approach incorporating a term for the heterojunctions between the two phases. Hydrogen fluxes of 0.004 – 0.008 µmol•cm-2•s-1 are obtained for a 50 volume % STN95 membrane sample (1 mm thickness) at 600 – 800 °C using dry argon as a sweep gas. Upon adding palladium layers as catalysts more than a five-fold increase is observed in the hydrogen flux, 0.025 – 0.026 µmol•cm-2•s-1, over the same temperature range. Hydrogen flux is not observed for membranes made from the 60 and 70 % STN95 samples.