Hybrid nanocomposites, such as ZnO nanowires embedded in conducting polymers, are very attractive for chemical sensing applications. Previous studies have shown that tuning ZnO nanowire concentration with respect to the polymer can be employed to tailor chemical sensitivity and selectivity. In this work, we investigate the effect of ZnO nanowire growth time on the electrical transport properties of sensors with and without the polymer matrix. Varying growth times may affect wire lengths, wire concentration, as well as wire interconnectivity. Using pure Zn as the source, ZnO nanowires are grown on a glass substrate by a low temperature thermal evaporation method. Poly(3-hexylthiophene) is employed as the polymeric matrix to form a hybrid structure. The response to ethanol vapor of sensors with different nanowire growth times is evaluated.