Steeping E-Liquid: Fact vs. Fiction
Steeping e-liquid is the process of intentionally aging it through various means, some more effective than others. Why? Often, especially with complex flavor blends, liquid taste tends to change over time as flavors meld and the true characteristics the mixer had intended come to life.
There are a few main things that can change the character of your e-liquid – light, heat, time and air. The first two, though, can be damaging, as they can cause nicotine oxidation that will give your liquid a harsh taste or crystalize artificial sweeteners, darkening your juice and clogging your coils.
We should mention here that most commercially available e-liquid doesn't require steeping – it's likely several weeks old by the time it passes from the manufacturer to the retailer to the consumer, which is usually plenty of time for the juice to mature. Some premium mixers even age their liquid on site before shipping it out, ensuring every bottle off the shelf is already in its prime. If you're buying from a discount mix-to-order online shop or a brick-and-mortar business where juice is being mixed up in the corner, you may encounter more problems with un-ripe liquid. This will usually be characterized by either chemical harshness or a taste that just seems "off," especially if you're familiar with how a flavor should taste.
Also, consider that simpler, single-note flavors like "banana" will need less steep time than complex blends like "chocolate caramel cream pie." Desserts and tobaccos will also often require a bit more aging than fruits.
If you think your liquid does need steeping, how might you go about it?
We've repeatedly heard that putting your sealed bottle inside a cardboard box will enhance its steeping. This one won't work, and will have no effect on your juice whatsoever. The color of the bottle you're using also has little effect on steeping – if you're constantly exposing your liquid to a direct light source, liquid in a clear bottle might show tiny signs of advanced aging after a period of time when compared to a dark amber or cobalt bottle, but the effect is going to be negligible.
Heat-steeping liquid is a popular technique among amateur mixers – an hour in a bath of hot water (hot as in out of the tap, not hot as in heated on the stove) is equivalent to a day or two's worth of natural aging. Also, when heated, the liquid's vegetable glycerin will thin, meaning that shaking it up to blend the propylene glycol-based flavorings will be more effective. Go too far with heat, though, and you could end up worse off than before you started.
How, then, should you go about aging your liquid? The best results can be obtained by leaving the cap off your liquid and storing it in a cool, dark place, like the corner of a cabinet. Leaving the liquid uncapped will allow any unpleasant vapors to evaporate (some flavorings, particularly cheaper ones, use small amounts of alcohol often responsible for harsh taste), and re-capping, shaking, and sampling your liquid once a day will allow you to decide when it's reached its peak potential.
Another option is leaving your liquid capped and stored, again in a cool, dark location. Steeping will take longer this way, but you'll ensure no dust or other unwanted debris gets into your bottle.
Taking things a step further, you're going to have the most luck if you have a few different flavors on hand, and stock up before you run low. This way you'll always have a fresh flavor ready to fall back on if you do happen to encounter one you think might not quite be ready for prime time.