In the pre-Hispanic Central Andes, the mummified bodies of ancestors stood as the basis for the social and cosmic order. However, the mummification techniques in that region are still poorly understood, as there have been surprisingly few archaeometric studies on their technical aspects. For that reason, we selected two mummies of the Chancay culture (900-1533 AD), on which to perform extensive chemical characterisation using a combination of molecular and elemental analysis and nanoscale imaging. The multimodal chemical study included the use of ATR FTIR, Raman spectroscopy, SEM-EDX, GC-MS and HPLC-MS techniques, and allowed the identification of a plethora of organic and inorganic substances present in their skin. Moreover, we were able to recognise different patterns of decomposition in each case. Data obtained during this study suggest that, in the last centuries before the Inca Empire conquered the Peruvian Central Coast, local societies treated some of their dead in a special manner, covering their bodies with balms composed of many substances. Some of these substances had anti-decay properties and could stop further decomposition of the skin.