The term "steeping" is most commonly attributed to the process of making tea out of hot water and teabags. However, that's not the only use of this term, and those who like to vape know this well.
So what is this other use? Well, essentially, it is a way of aging the juices in your vape’s tank to remove bottle tastes and alcohol. It mixes the Propylene Glycol (PG), Vegetable Glycerin (VG), flavors, and Nicotine. This allows the PG and VG more time to absorb all the flavors. After, darkens the liquid by removing the alcohol. This allows, as some say, the best flavor of the vape to come out.
So how does one steep vape juice? Well, the tried and true way to do it is storing the e-juice in a dark, cool place for a few weeks. While it is steeping, it needs to occasionally be shaken and exposed to oxygen. However, there are a few different ways to get some faster results.
One way of steeping is by warming the juices. One method is simply placing your e-juice bottles in a Ziploc bag and then in warm water. Wait until the water becomes room temperature, then uncap the bottles to release any gasses that may have accrued. Once all this is done, recap and give the bottles a good shake. You can also place the bag under some warm rice and wait for it to cool. This method also requires uncapping for the release of gasses. Placing the juices in the glove box of a warm car for a few hours also works, but is limited to the summer time.
Another way, that doesn't involve warming the juices up, is mixing a little bit of already steeped juice into fresh juice, and leaving to sit in a cool, dark place. This will mimic the original method but will shorten the time from a few weeks, to a few days.
Now, steeping tastes vary from vaper to vaper. Some people don't wish to steep their juices at all, enjoying that harsher hit, while some enjoy steeping every juice they obtain for a longer period. Then there is the middle ground of people who choose to use the shorter methods of steeping. It really comes down to the personal taste of the consumer. Each juice isn't steeped equally either. Lighter and fruitier juices require very little steeping. In fact, too much steeping with a lighter juice may result in it losing all flavor in general. Tobacco flavors require a little more steeping, and dessert/creamy flavors tend to require the most steeping.
Whether one chooses to steep or not, it is very important to take the proper precautions. Always use glass bottles while steeping because plastic can melt and spill the juices. If one likes to steep for longer periods of time, it's imperative to avoid going past the expiration on the bottle.
The best thing is to figure how to steep for personal preference.