The taste of e-liquid can change tremendously over time. Some flavours taste great immediately, but others take more time and work to get to the right place. The process of waiting for an e-liquid flavour to mix with the nicotine is called steeping. Vapers vary drastically in their opinions on how to steep, but is steeping really even necessary?
There are almost as many methods of steeping as there are vapers. Some just let the e-liquid alone for a week or two, shake the bottle, and vape. Others shake the bottle immediately upon receipt and again every night or two for a week. However, some vapers would argue these methods are technically aging, not steeping. Those vapers feel steeping involves immersing the bottle in hot water. When a vaper first receives a bottle, especially if it is freshly mixed, there may be numerous bubbles visible. The steeping process is an attempt to eliminate these bubbles. Heat will help the e-liquid flavour to mix with the nicotine faster. Still others prefer to allow their bottles to sit with the cap off for a while to allow the e-juice o breathe for anywhere from three to seven days, but some vapers refer to this process as breathing rather than steeping. Whether what one prefers to age, steep, or breathe their juice, or use some combination of the three, almost all vapers feel something is necessary to bring out the best flavour in their e-liquids.
With so many different methods, how does one know which level of interference is going to result in the best flavour? Unfortunately, the only answer is trial and error, but there are some general guidelines about what may help and what may actually do damage to the flavour. For instance, breathing is more likely to result in loss of flavour than in flavour enhancement. Most vapers who breathe their liquids over-breathe them. In my opinion as an experienced vaper, taking the cap off for a minute or two every couple of days is enough breathing. I have not found breathing an e-liquid for long periods of time to help the flavour, yet I have found that breathing for even a half an hour is likely to ruin an otherwise good flavour. In addition, I have not found putting bottles of e-liquids in hot water particularly helpful. It does seem to get the e-liquid flavour and nicotine juice to mix faster, but aging the flavour is still necessary, and I have found they mix just as well when I just wait for them to do so on their own. My personal method is nearly minimum intervention. I let the bottle breathe for a minute when I first get it and then replace the cap and shake the bottle. I repeat the same process every two days for a week. Then, I perform a taste test and either begin vaping it or let it sit another week based on the results. E-juices mix themselves almost entirely on their own.
While there are many different steeping processes people will use, it is not necessary to go to so much work to get the best flavour out of an e-liquid. The single most important aspect of steeping is aging the e-juice. Otherwise, it largely takes care of itself. So, quit exerting effort to get great flavour. Instead, just give it a little time.