In this work we have studied water evaporation from porous silicon layers by means of in-situ, time-resolved Raman spectroscopy. Stress effects are detected to occur during water evaporation, while the Raman peak variations during drying confirm the hypothesis of destruction of smaller nanostructures. The Raman results are corroborated by electron microscopy and photoluminescence investigations carried on air-dried and supercritically dried samples. The present study shows that avoiding the capillary forces during drying is a fundamental step for technological applications of porous silicon. Furthermore, proper drying processes allow one to obtain luminescent porous silicon from a variety of differently doped substrates, opening new possibilities from both a fundamental and a technological point of view.