The opportunities of using hydrophobic pervaporation to concentrate organic components in aroma recovery and wastewater treatment have been recognized widely. The focus of this article is on the influence of the support layer on the mass transfer in hydrophobic pervaporation. Even though the influence of the support layer on the overall mass transfer has been observed experimentally, the modeling and analysis of this aspect has been widely neglected. The aim of this study is to build a bridge between modeling of the influence of the support layer and experimental data. Therefore, an improved modeling approach is proposed and used to analyze experimental data for the permeation of the two binary systems water-phenol and water-chloroform through hydrophobic composite polydimetylsiloxane membranes. Comparing the experimental results with the model, it has been observed that the mass transfer of the support layer depends on both physical and chemical properties of the support layer. On the basis of these observations, guidelines for the selection of support layers will be presented.