Why Does Vape Juice Turn Brown or Dark?

Vape juice turns dark or brown for two reasons: the sugars in the e-juice have caramelized from heat exposure or the e-liquid has expired from oxidation. 

You can determine the cause of your e-liquid turning dark brown by tasting it. 

Caramelized e-juice will have the same flavor as normal juice but will have a thicker texture than usual. Expired e-juices will have a bad taste when you smoke them, but rest assured, they aren’t dangerous.

Either way, e-liquid that is turning brown can break your vape. When e-juices get darker, it means they’ve been stored improperly or exposed to excessive oxidation. 

If you notice dark, gunky stuff in your vape tank or on your coil, it’s time to switch out your e-juice bottles and clean out your tank.

Ultimately, to avoid any problems, you should be storing your juice in a cool dark place.

If your e-juice has turned brown (or even black), the next few sections will give you the facts you need to know. 

We’ll give you the chemical explanation for why e-liquid can change color, followed by some tips on how you can slow down the process.

At the end of this article, we’ll give you the quick answers to these frequently asked questions.

So first up:

Why Does Vape Juice Turn Brown?  

E-liquids get darker from one of two chemical reactions: caramelization or oxidation. 

Caramelization happens when sugars are exposed to high temperatures. The oxidation process happens when the nicotine in the e-liquid is exposed to excess oxygen.

Caramelization does not affect the flavor of e-liquids, but oxidation does. It can be hard to tell which is responsible for the dark coloration until you smoke it. 

Luckily, smoking caramelized or oxidized e-liquid isn’t dangerous – it just might be unpleasant.

Caramelized Vape Juice

If you’ve never watched baking shows on the Food Network before, here’s one sentence on the process of caramelization: 

Basically, caramel is made by gradually heating sugar over high temperatures. 

Anything with a lot of sugar can be caramelized if subjected to high enough temperatures, including e-liquids.

For nicotine e-juices to taste good, manufacturers add sugars and artificial sweeteners. The sugar (and added sweeteners) make every hit delicious, but they also make the e-liquid sensitive to higher temperatures.

If your e-liquid reaches high temperatures, it may caramelize and thicken. Of course, you have to expose the e-liquid to fairly high heat – leaving the bottle out in your home isn’t going to cause caramelization (usually).

Your best bet is to store e-liquids in a cool place away from direct light. This will help prevent them from turning brown.

Is Caramelized Juice Bad?

Even though the caramelized e-liquid may look dark, muddy, and a bit gross, it’s still technically good. It will likely still have the flavor you enjoy, but since it may have gotten thick and gunky, it might be difficult to smoke. 

You can continue vaping the caramelized e-liquid in your tank, just be aware that it can build up a residue on your atomizer leading to a burnt coil and dry hits. 

Just make sure to regularly clean your tank and replace your coil when needed.

Oxidized Vape Juice

Just like most other foods or consumable products, e-liquid can go bad. This is mainly because of a chemical reaction between the sugar, flavorings, and nicotine, and the air. 

Whenever these ingredients are exposed to oxygen, they undergo the oxidation process, changing their flavor, smell, and look. 

This is especially true for nicotine, which is a volatile chemical, sensitive to the air (and to light).

Once e-liquids have oxidized, they’ve technically expired. You can feel free to smoke them, but it’s likely they will not taste great – most people will willingly throw away an expired bottle based on this fact alone.

Is Oxidized Juice Bad?

Oxidized vape juice is bad-tasting vape juice, but it’s not poisonous. 

There are no studies that show that expired e-liquids are more dangerous than unexpired ones, but they definitely may not be appetizing. You can keep smoking a bottle or tank of expired e-liquid until you notice a difference in flavor.

Also, and importantly, expired e-juice can damage your vape if kept inside the tank for a long period of time. We recommend cleaning out your vape tank regularly and getting a fresh bottle of e-liquid when it expires.

How Can I Prevent My E-liquid From Browning in the Bottle?

Once your vape juice turns brown in its original bottle or vape tank, you can’t make it clear again. The best way to slow or prevent vape juice from browning is to store it in a cool, dry place. 

Know Your Liquid

Not all e-liquids expire at the same time. For some brands, the process can be slow. 

An e-liquid brand with propylene glycol (PG) flavors will last the longest, but a brand with vegetable glycerin (VG) flavors are the sweetest. 

Knowing whether you have PG or VG liquids can help you estimate the sugar content and expiration date. E-liquids made with propylene glycol tend to last around two years, whereas VG liquids last anywhere from one to two years.

Store Correctly

All e-liquid bottles should be stored correctly. A good method is to store your bottles in a cool dark place. 

Don’t place your juice bottles in direct sunlight, near heat sources, or in freezers. Darker places, such as drawers, work best.

Don’t Mix Juices

Mixing is one of the worst things you can do if you want to prevent vape juice from browning. 

Nicotine is a highly reactive chemical, so whenever you mix juices, you expose both bottles to the air, which leads to premature expiration. 

Instead, we highly recommend using one flavor at a time to ensure you don’t contaminate or oxidize any of your bottles.

Clean Your Vape

Although cleaning your tank won’t completely protect your juice from browning, it helps. Regular tank cleaning also keeps your vape in prime working condition. 

As soon as you notice that your vape juice is getting darker, empty your tank and clean out any gunk. The gunk will damage and stain the tank!

FAQs About Vape Juice Turning Brown

Why does clear e-liquid turn brown?

Clear vape juice can get darker when exposed to either excessive heat or oxygen in your tank or bottle. 

Heat causes the sugar and added sweeteners in the e-liquid to caramelize. 

Oxygen exposure degrades nicotine and other ingredients, causing the liquids to expire.

Is it bad if my e-liquid turns brown?

It isn’t always bad if vape juice darkens. 

For example, juice that has caramelized is not expired and will likely still have the same flavor. 

Oxidized e-juice, however, is expired and probably won’t taste the same.

Can I use brown e-liquids?

Technically, you can use e-juice after it turns brown, but you might not want to. 

Oxidized vape juice will often have a different smell and nasty flavor. We recommend tossing out any expired juice, but it will not hurt you to try it.