As for lamping/sunning/airing - aren't these methods used just for very fresh oils that still need some water/hydrosol etc. removed, similar to the setup with lamps we saw in your recent videos?
Also - I am curious as to whether the plastic applicator sticks used in the standard octagonal bottles may affect the oil over the long run? And is there any danger in keeping the oils in the fancy crystal bottles with metal elements? I could be wrong but I heard that the copper in the metal neck/stopper can impart a greenish tint to the oil? If that's true, can this also affect the smell of the oil?
Lastly, would it be of any beneift to replace the air in the long storage bottles with an inert gas is this a ridiculous overkill?
The lamping and sunning are initially used to help the water and oil molecules separate, so that the oil can then be filtered. However, many people employ these techniques in order to intentionally oxidize or force-age an oil and induce a mellower, more mature aura to the fragrance. This is very different to the natural aging that happens if you keep the oil in a tightly sealed bottle over years and years, in a cool dark place. The oil loses its vitality, and what you smell in the end is the oxidized molecules which often have a rancid linear smell, rather than the original fragrance of the essential oil itself.
I've been wondering about the plastic applicators for a long time. All of my personal stash is poured in plain glass bottles, and I use nothing besides. To date, I haven't seen (or sniffed) anything that would indicate the plastic applicators have an impact. The metal elements of crystal bottles, on the other hand, will impact the color of the oil if not stored with care and kept upright; i.e. if the oil comes into contact with the metal (copper, to be exact) parts of the bottle and is then exposed to oxygen, this will lead to copper sulfate occurring inside the bottle, imparting a green tinge to the oil. If allowed to age long enough, the oil will eventually turn a dark green color. I'm not sure this has an effect on the smell, however it is quite off-putting to see the color of the oil change.
For this reason, I recommend everyone use the plain glass bottles; or if you must, the gold or silver ones, which must be kept ultra clean at the neck, ensuring the oil doesn't come into contact with the metal.
@asi17, I'm so sorry to hear about that happening to your bottle of Oud Mostafa! I recommend you pour it into a plain glass bottle immediately, to prevent the occurrence of additional copper sulfate in the oil.