Shelf-life of Perfumes
6 years ago
I would like to start a seriously frank discussion on a subject that might be seriously scary to persons with large collections. My collection is now large enough for it to be seriously scary to me, so I am not here aloof scaring other people!
I will start be saying that on the whole the results are quite reassuring: my testing of my oldest 'fumes, the high prices often commanded by pre-reformulation specimens, and reports from persons who have one way or another gotten hold of some old bottle or other.
I do know that hard & fast good-storage rules are to keep it away from ultra-violet light, & any other ionising radiation (such as one's nuclear pile (doesn't everyone have one?)), and unheated in a way that, to speak technically puts it out of thermodynamic equilibrium. By this I mean that if you put it, say, on a hot surface, heat is being applied at one part, so that there is an 'enginry of heating' through the body of the stuff - and that would be _bad_; whereas if it is in a room of which the temperature gradually rises, the stuff is in a static condition, but its temperature just happens to be higher at a later time - and that is not so bad. (This is why some foodstuffs are baked in the oven - so that they become hot without departing much from thermodynamic equilibrium. We all know that you cannot bake bread by putting dough on a hotplate - you'll just get a mess. By the same token, non-equilibrium heating is _very bad_ for a perfume, whereas equilibrium heating is not so bad - but probably still a little bit bad at least.) So _don't_ put your perfume next to an intense localised heat-source!!
Anyway, I am _very_ keen to learn of the experiences of others at assaying of old specimens of perfume; I do not say 'glad' - I might well not be! - but please do lay it on anyway!
I will start be saying that on the whole the results are quite reassuring: my testing of my oldest 'fumes, the high prices often commanded by pre-reformulation specimens, and reports from persons who have one way or another gotten hold of some old bottle or other.
I do know that hard & fast good-storage rules are to keep it away from ultra-violet light, & any other ionising radiation (such as one's nuclear pile (doesn't everyone have one?)), and unheated in a way that, to speak technically puts it out of thermodynamic equilibrium. By this I mean that if you put it, say, on a hot surface, heat is being applied at one part, so that there is an 'enginry of heating' through the body of the stuff - and that would be _bad_; whereas if it is in a room of which the temperature gradually rises, the stuff is in a static condition, but its temperature just happens to be higher at a later time - and that is not so bad. (This is why some foodstuffs are baked in the oven - so that they become hot without departing much from thermodynamic equilibrium. We all know that you cannot bake bread by putting dough on a hotplate - you'll just get a mess. By the same token, non-equilibrium heating is _very bad_ for a perfume, whereas equilibrium heating is not so bad - but probably still a little bit bad at least.) So _don't_ put your perfume next to an intense localised heat-source!!
Anyway, I am _very_ keen to learn of the experiences of others at assaying of old specimens of perfume; I do not say 'glad' - I might well not be! - but please do lay it on anyway!