An in situ Raman measurement system is introduced, which allows the real-time monitoring of the supercritical CO2 extraction of hop. During the extractions, which were performed in a lab-scale extraction plant at NATECO(2), the hop extract concentration in CO2 and also the amount of alpha-lupulic acids in the extract were measured. For the required optical access, a high pressure Raman sensor was designed and constructed, which could be easily installed inline between extractor and separator. The applicability of the presented measurement system is shown by monitoring the scCO(2) extractions of two different hop varieties under relevant extraction conditions of 333 K and 20 MPa, 24 MPa and 28 MPa, respectively.