Hi Doug,
Yeah, what Snow Dog said.
Some flavors are more "steep-dependent" than others. Specifically tobacco flavors almost always change over time. You may open up a new bottle out of the package and it'll smell like it could gag a maggot, but a week or even a month later it's really pleasing to the senses.
A simple one flavor-component juice like a single fruit is usually wysiwyg. You can vape it out of the bottle and it will usually be what it will always be. Sort of.
The thing is, the way the juice is made is a combination of different viscosity. You've got PG (Propylene Glycol) which is thin and VG (Glycerin) which is very thick. Then there is the base flavor which is mostly always PG based. And then the nicotine-carrier that could be either PG or VG based. Sometimes it takes a while for it all to meld.
The quickest and slickest way is to buy an ultrasonic jewelry cleaner,set your bottle(s) in that for several cycles and 2 or 3 hours can equal days or weeks,even, of just sitting on the shelf.
There are many threads here on this method.
Personally, I wedge a box of juice in between an old converted attic fan(and it's frame). The thing vibrates like a jackhammer and after a few hours the juice actually changes color. Which is an indicator of accelerated aging. Yeah it's Über-Redneck, but never forsake the genius inherent in "Duct-Tape and Baling wire"
Good luck
