I can see how it would be confusing, but I think I can help make it less so.
There are two different things that may, not always, have an impact on the flavor of your vapor.
Steeping is a capped bottle of
e-liquid sitting for a period of time, away from light, to allow entropy to happen. Basically a no-effort method to ensure the mixture is full dispersed and any reaction between the various components have time to occur. Cap On is Steeping.
Airing-Out, or Breathe, is an uncapped bottle of e-liquid sitting for a period of time, away from light, to allow the more volatile flavoring notes to escape, and/or allow some alcohol flavoring carrier to evaporate, and/or start oxidizing the nicotine to impart more bitterness.
While you Breathe an e-liquid, it does do some steeping, but it does something different to the taste of the vapor that steeping alone does not do. I find it a shame that the two different methods, that do two different things to flavor, have become confused, but it has happened over the years here on ECF.
Note that neither Steep or Breathe is a magic thing, nor do they always work to make a taste better and it is possible that they could make the taste worse. Both of them are something that may be tried if the flavor of vapor you have is not to your liking. Plus it is an individual thing. I know some folks insist that all tobacco flavored liquid needs steeping, some that insist that all tobacco flavored liquid needs airing-out, but I have not found that to be the case for me, but I do not doubt it is true for those who say such.
I vape my own mixes exclusively and have been making my own e-liquid for a few years so I have many recipes that I think are great. There are a handful I have found that are better after a steep. There is one that I have found that is better after a breathe. Most of my mixes are perfect from the moment I first shake the bottle. I know which method works, or doesn't work, for me because I've tried them myself to see.
The best way is to see for yourself. If it's good from the first time you try it, then don't worry about either. If it isn't, try keeping the closed bottle away from light for a period of time and see if that helps. (I know some who say it takes a month for them, but the longest one I have encountered takes 2 weeks and most take less time than that.) If the steep did not help, then give it a chance to breathe, open bottle in a drawer is great for that. If either work, you will know next time you obtain that specific e-liquid what you can do to make it better for you. If neither work, I would strongly suggest never obtaining another bottle of that specific e-liquid.
Hopefully the above was of some help.
