An uncertainty analysis was performed on a mechanistic model describing the transport and oxidation of methionol, a model aroma compound, in PET-packed rosé wine. This allowed to quantify the relative importance of the losses to the wine/packaging material (scalping) with respect to those due to oxidation over a year of storage. Additionally, the oxygen scavenging effect of SO2, was also evaluated. Results showed that the predictions of the wine concentrations of the three studied species –methionol, oxygen and SO2- are reasonable, and that the reaction pathway is largely dominant with respect to losses of methionol and SO2 through the wine/packaging interface. Contrarily, the oxidation reaction appears to be almost equally governed by the kinetic reaction constants and by the oxygen barrier properties of PET in some of the tested scenarios, and thus likely responsible of a large proportion of the uncertainty.