Effect of Palletisation and Temperature on Bag-in-Box Wine Packaging Under Simulated Export Conditions

Bag-in-box (BiB) wine packaging is increasingly used for export, but conditions inside palletised units are rarely measured directly. We instrumented 3 L BiB units with in-bag MEMS pressure and temperature sensors during a 20-day static chamber trial using 19 °C and 50 °C set-point chambers, labelled C19 and C50. The set-point labels do not represent measured wine temperatures. A 15-day single-stack verification trial was also run at the C50 set point. In the main trial, the measured in-bag temperature differed strongly from the chamber set point. C50 packages stabilised at 34.2 ± 0.4 °C in the top units and 26.1 ± 0.2 °C in the bottom units, while C19 units remained around 22.8–23.5 °C. In the verification trial, individual sensors reached 45.0–48.8 °C, but no in-bag sensor reached 50 °C. Internal pressure rose after handling and peaked between day 3 + 13 h and day 5 + 19 h. Bottom-position units showed a larger uncorrected peak ΔP than top-position units (adjusted difference: 20.4 mbar; F(1,8) = 9.14; p = 0.017). The position result is interpreted as exploratory. The pressure analysis used a small unbalanced sensor-level design, with one missing bottom-position C19 trace, no barometric reference logger, and no retained stack pairings. Bulk wine from C50 showed lower free and total SO2 and higher volatile acidity than wine from C19. Lactic acid was significantly higher in C50, although the underlying mechanism could not be established and residual microbial activity cannot be excluded. Overall, chamber set points were a poor proxy for actual in-package conditions. Selected sentinel packages can document real thermal and pressure exposure in palletised BiB wine.