The invention concerns a method and system for determining the age of an object such as a product containing volatile components, comprising: measuring a first strength of a first scent with a first electronic sensor, the decay rate constant of the first scent being known; measuring simultaneously a second strength of a second scent with a second electronic sensor, the decay rate constant of the second scent being known; calculating a current scent ratio (.sigma.) of the two scent strengths; and determining the age of the object from a reference time for which a reference scent ratio (.sigma..sub.0) of the scent strengths has been registered.