Have you ever noticed how some e-juices change color over time? Either a nasty dark brown color in the bottle or a deep amber color in your tank? You may have thought it was the e-juice going bad or your coil biting the dust, but there’s a little bit more involved than that. In this article, we’re going to fully explain why e-juices change colors, as well as some ways to prevent that.


If you’re worried about your e-juice turning dark whilst in your vape tank, then this is most likely down to the ingredients. The majority of e-juices on the market are filled with artificial sweeteners and sugars which add the flavour to your favourite e-juice.

When your e-juice is exposed to heat, this is where things start to take a turn. The sugars in sweet e-juice flavours will caramelise when exposed to the heat, and in turn, this will change the colour and texture of your e-juice. Just like the process of making caramel, the result can be a bit ‘gunky’, but not necessarily bad!

It is worth mentioning that this caramelised gunk can also stain the inside of your vape tank, and over time build up on the coil and seep into the tank, leaving residue behind. If you don’t clean your tank regularly, the build-up of residue will begin to stain any new e-juices added to your tank as well, and will eventually affect the taste.

If you have e-juices turning dark in your tank that isn’t a sweet flavour, then you may be questioning what this means. Well, if you have left your vape neglected over some time, a chemical reaction process called oxidation may start to occur. This is where nicotine and oxygen are exposed to one another for a long period of time, and although it may create a funky colour, it won’t ruin the taste or quality of your e-juice.


In some cases, your e-juice might start to turn dark whilst it’s still in its original bottle. This is actually because of the same oxidation process we have previously mentioned, oxidation isn’t limited to old vape e-juice left in forgotten tanks, but it can also happen inside the bottle. If you haven’t used an e-juice in a long period of time, you might be a bit startled to see that the e-juice has changed from a soft yellow to a muddy brown.

The consistency will still be the same, but now the e-juice looks gross and unappetizing to put into your bottle. Light and heat speeds up this oxidation process, which is why, we recommended storing your unused opened bottles of e-juice in a cool dark place. Granted, this won’t stop the oxidation process completely, but it will certainly slow it down.

Nicotine is an extremely reactive chemical, and should be treated with care to ensure your favorite e-juices don’t turn brown before you’re ready to use them.


Although we want you to know that your e-juice turning brown is not a cause for concern, we understand that it can be annoying and a little bit off-putting. This is why we have put together a few simple tips that can prevent or even just slow this process so that you can happily enjoy your e-juices and their desired colours for longer.

1. Consider the Ingredients

As you are probably aware, there are hundreds of e-juice brands available on the market today, and just like with any popular product, not every brand is dedicated to the highest-quality ingredients. If you choose a cheaper e-juice brand, then you should be wary that the ingredients may not be the finest quality, and it can be these ingredients which cause your e-juice to turn brown faster than others. You should also take note of vegetable glycerin-based e-juices, as these are often the sweet flavours you will find online. Generally sweeter than other flavours, VG e-juices tend to darken the fastest, so instead opt for a more natural e-juice option or PG based e-juices.

2. Make Sure Your Store Appropriately

If you want to reduce decolourisation or sticky gunk build-up, then take the time to ensure you’re storing your e-juices in the right places. Make sure that lids are tightly closed and store both vape devices and e-juice bottles in cool, dry and dark places.

3. Never Mix!

Our golden rule to you is never to mix your e-juices. Even if you have an old and new bottle of the exact same e-juices brand and flavour, you shouldn’t be mixing them. Always keep them separate. If you are mixing different flavours of e-juices and different brands, we recommend you do so in a small container. This way, you don’t risk affecting the entire bottle. If you do find your tank is starting to change colour, never go straight in by adding a new e-juice. Take the time to clean the tank first to remove any caramelised build-up, which might affect the taste and quality of a new e-juice going in.

4. Finally, Keep it Clean!

We’ve said it once, and we’ll repeat it, always make sure that you’re keeping your vape tank clean. If you make sure to stick to a regular cleaning routine, then you can ensure you’re getting the most out of your vaping experience. How often you should clean your tank depends entirely on how often you use it, but you can find out more about cleaning your tank in our guide. For safety, we recommend cleaning your tank every time you change your e-juice, as this will ensure the removal of any caramelised gunk threatening to darken your vaping experience!

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