Steeping is a process that happens to e-liquid over time. It's also used in the production of e-liquid. Steeping is letting the juice “age” over a period of time to improve or strengthen the flavours making the e-liquid darker in colour. It's also dependent on the nicotine strength, the higher the nicotine the the darker it will appear. Steeping e-liquid is something that can be done on a small, DIY scale as well as an industrial one. So, if you want to improve an e-liquid’s taste or just want to see how it changes after steeping, you could try one of the methods below.
Breathing & Steeping
The most popular method of DIY steeping is to just let the bottle of e-liquid sit in a cool, dark cupboard for a couple of days, giving the bottle a good shake every now and then. Simple. There is an optional step to this method known as “breathing.” This basically means letting the bottle of e-liquid sit in the cupboard with the lid off for no longer than 10 hours. Steeping of the e-liquid is then resumed with the lid attached. Your liquid may slightly change colour over this process due to oxidation of the nicotine (this happens whether you “breathe” the liquid or not). Remember that all e-liquids are different, so there is no set amount of time you are supposed to steep for. Leave your liquid for two days at first, and then try it. If you aren’t happy with the results then just give it some more time. Also, more complex e-liquids will take longer to steep than simpler ones. For example, the mix that is made up of 4 flavours will take longer to steep than a mix with only one flavour.
Warm Water Method
This method can speed up the steeping process and is also very simple. It consists of keeping your bottles of e-liquid in hot water (never boiling water though as this could possibly damage the nicotine), for a couple of hours before placing the bottles in a cool, dark cupboard. The water temperature temporarily thins out the e-liquid, allowing it to mix faster. If you use the warm water method then your liquid won’t require as much time in the cupboard and you can test it after one day instead of two. Again, steeping e-liquid isn’t an exact science and the time your liquid needs, or if it needs it at all, is completely down to your own preference. Just make sure you don’t go past any use-by dates that a manufacturer may have included!