Definition: Hydrogen sulphide

A foul-smelling gas reminiscent of rotten eggs, it comes from reductive combinations of sulphur in poorly conducted winemaking processes. Hydrogen sulphide or sulphuric acid also leads to mercaptan odours. Slightly noticeable in a bottle, these odours can disappear by aerating the wine thoroughly, for example by decanting it from a height into a carafe or using a specific oxygenation accessory. A foul-smelling gas reminiscent of rotten eggs, it comes from reductive combinations of sulphur in poorly conducted vinification processes.