The stability of parthenolide, the active ingredient in feverfew and a potential anti-inflammatory bioactive in beverages was evaluated at different pHs (2.9, 3.7, 4.6 and 6.0) during heat processing at 40–100°C. The residual concentration of parthenolide was analysed by High Performance Liquid Chromatography and degradation kinetics determined using a non­isothermal method. Parthenolide degradation with thermal treatment followed pseudo-first order kinetics. The stability of parthenolide was significantly affected by pH and processing temperature. Feverfew infusions at near neutral pH levels exhibited good stability but a significant decrease in stability was observed at lower pHs. This model is likely to be a useful tool to predict the optimum pH and time-temperature profile required to retain parthenolide during heat processing.