Has the pale e-liquid you received a short while ago begun to drop a from a pale yellow to a dark orange? Has the clear e-juice you originally put into your tank started to develop little amber streaks and swirls in the tank after a few vapes?
Don’t worry, it’s normal.
There are a load of reasons this can happen, and it’s unlikely you should be worrying. Worst case, you might need to change your atomiser or put in a fresh wick if you’re on a rebuildable.
You know what happens in the atty when you press the switch (coil gets hot, juice turns to vapour) and you know what’s in your e-liquid (PG, VG, flavour concentrates, nicotine base). So knowing that, here’s why:
#1: E-liquid getting darker in the bottle
The components that are going to get darker are the flavour concentrates and the nicotine base. Minor colouration will develop over time and even clear zero nic juice may see a slight change from almost transparent to a mild yellow.
Flavour concentrates with no added colour may still be dark. Deep rich tobaccos and some vanilla concentrates are almost black, hence the colour, but even naturally lighter colours can deepen over time.
Nicotine content is a factor in the deepening hue. Time and heat combined can serve to change a pale e-liquid to a deep, dark amber. Zero nic juice may darken over time too, depending on the flavour components. It’s normal.
#2: Wisps of dark liquid in my otherwise clear tank
It’s either gunk or the power is up too high.
When you press the power button on your electronic cigarette, you send a current through metal coils that heat the e-liquid in your atomiser / tank / dripper. The heat turns some of the juice to gunk that sticks to the coil.
If you use replaceable tanks or coil heads, you’ll notice that the draw gets tight and maybe gurgles around the same time. Gurgling in a tank means the flow of juice is not as smooth as it should be as the residue from your juice caramelises and sticks to the coil. If you coil your own, you’ll know this only too well – the black cotton with a heavy crusty coil.
When you have a fairly clear e-liquid and notice little dark wisps or liquid creeping into the tank, don’t worry. You’ve probably been getting good use out of that tank / coil and it’s time to replace it. You can keep using it, but the draw will get tighter as the normal airflow is restricted by a larger gunky coil and the taste will become more muted. Keep a spare head handy or wrap a fresh coil.
Alternatively, you have a device with some power behind it and you’re going too hard and too fast. The wick needs to be wet and if it’s not replacing the juice as fast as you vape it, it will taste burnt and will actually burn (or caramelise might be more accurate).
If you have a device that allows you to change the voltage or wattage, try turning it right down and try for a lighter vape. It’ll prime the coil and cotton and allow the coil to wick at a similar rate to how it’s vaped.
Darker juice or e-liquid that gets darker over time is not a bad thing. A lot of the time it’s better actually (steeping), but if you have gunky juice, change your coils