The experiment here proposed concerns the study of the vibrational properties of liquid water-methanol mixtures in the solid phase as a function of the concentration, and exploiting selective isotopic substitution. We aim at providing additional insight into the clustering dynamics suggested by previous neutron diffraction and x-ray emission spectroscopy experiments, whose results put under strong discussion the long time accepted ¿iceberg model¿. We intend to focus here on water-methanol mixtures, where the use of a small amphiphilic molecule can be employed as model system to understand the interactions between amphiphilic groups belonging to much larger molecules, and water. We expect that this experiment will provide unique information on the way the local environment of methanol molecules (in particular H-bonded ones) changes with water concentration.