We studied the capacity of glutathione and a specific inactivated dry yeast rich in glutathione to protect white grape must from browning compared to using sulphur dioxide. The results indicate that sulphur dioxide drastically reduces the oxygen consumption rate, protects hydroxycinnamic acids from oxidation and prevents grape must against browning even in the presence of laccase. Glutathione, pure or in the form of a specific inactivated dry yeast rich in glutathione, also reduces the oxygen consumption rate but to a lesser extent than sulphur dioxide. It favours the formation of GRP from hydroxycinnamic acids and effectively protects grape must against browning in healthy grape conditions. Nevertheless, in the presence of laccase it was not effective enough. Therefore, both forms of glutathione can be considered as interesting alternative tools to sulphur dioxide for preventing browning in white grape must, but only when the grapes are healthy.