E-liquid. It’s one-third of the Holy Trio of Vaping Without Which There Would Be No Vaping (the others being the coil and the battery), and by far the most delicious. It’s also arguably the most diverse, with flavours as varied as birthday cake, dragonfruit, and for some reason, Worcestershire sauce. And the powers that be are coming up with new e-liquid flavours all the time.

So we thought that we’d take this opportunity to cover just about everything we can think of related to e-liquids. Welcome to the Vapour Guide to E-liquid.

What’s an e-liquid

We realise that this is a sort of vape-centric corner of the Internet and if you’re reading this, you probably already know what e-liquids are, but humour us, just for a second.

E-liquid is the vapour that comes out of a vape. When you hit the firing key on your vape, the battery pushes a current through a coil, which is itself sitting in eliquid. The coil gets so hot that it starts to vaporise the e-liquid on contact. This is fed up out of the tank, where you inhale, and then (hopefully) exhale it.

E-liquid also tends to go by a handful of names—e-juice, vape juice, vape liquid—but they all refer to the same basic thing. We’ll cover how e-liquids can differ from each other a little further below.

What’s e-liquid made of

E-liquids are remarkably simple. They’re made of a base of propylene glycol (PG) or vegetable glycerin (VG), along with some flavourings and water. That’s basically it. This makes e-liquids very easy to create, but very difficult to get right, since those four ingredients can be mixed and remixed to make thousands of different combinations. Of course, differences in flavour have the biggest impact on the experience of vaping a certain e-liquid, but most vape users also consider the balance of PG and VG in their e-liquid. A liquid’s PG/VG ratio have a significant impact on your vape, and a solid understanding of what they contribute is the basis of any good e-liquid choice.

PG can hold a flavour very well, and doesn’t produce a lot of vapour when heated, which makes it excellent for providing intense hits with relatively little fuss. You’ll find high-PG e-liquids with much higher nicotine concentrations precisely for this reason: low vapour production leads to less nicotine in each hit. Ramping up the nicotine concentration is how high-PG e-liquids can provide enough nicotine to soothe your cravings. This is doubly good for e-cigarettes with small form factors or smaller batteries. Since you’re not vaporising a ton of e-liquid, you don’t need a ton of electricity. For this very reason, vapes like our very own VL4 and EVOD 650 do best with high-PG e-liquid, and struggle a bit on a e-liquids with lower amounts of PG.

VG, on the other hand, readily vaporises, and can take a real beating from a battery. When you see videos of people blowing huge clouds of vapour—it’s because they’re using a high-VG e-liquid. VG is slightly sweet in and of itself—it’s often used in candy production—and is significantly thicker than PG, which means you’ll often have to wait a little longer for your wick to soak up a high-VG e-liquid. But when it does, you can push huge amounts of power through it to blow massive clouds and even a couple of rings if you know the right mouth configurations. High-VG e-liquids were long seen as a bit of a niche product for the vape enthusiast but they’ve since been winning hearts with the evolution of the shortfill (more on that below) and the widespread realisation that the bane inhale is frickin dope.

What an e-liquid is not

E-liquids aren’t oils. With the rise of cannabidiol (CBD) and a cornucopia of CBD oil vaporisers, it’s easy to get confused between the two. However, neither PG nor VG are oils (although VG is made from plant oil, usually coconut or palm). E-liquid, unless explicitly stated, doesn’t contain any CBD, and doesn’t contain any oil.

E-liquids aren’t organic. Generally. In the UK, foods labelled as ‘organic’ tend to need to jump through a few hoops. They have to avoid fertilisers and chemicals, use certain approved products to process them, and control weeds and land fertility using ‘husbandry techniques’. This pretty much rules out PG, which is a synthetic substance, as well as nicotine, which uses non-EU-organic-conforming processes to be produced. Vegetable glycerin, however, can be organically produced, albeit at great expense. Which means it is possible for an e-liquid to be organic, if it’s 100% VG and nicotine-free.

Still, we haven’t seen any e-liquids like that—and certainly none bearing the EU organic logo.

Speaking of nicotine

A great majority of the e-liquid that we sell here everyday has nicotine in it. While many do find that they enjoy vaping even after they’ve beaten their addiction to nicotine, most vape users vape as a means of quitting smoking, and for that reason vape using nicotine-containing e-liquid.

How much nicotine you’ll want in your e-liquid is a matter of preference. If you’ve been a heavy smoker for a long time, it’s likely that you’ll need a much higher nicotine concentration than if you’re just a light social smoker.

In the UK, the highest strength that e-liquid can be sold at is 20 mg/ml, but for most brands, the highest concentration that you’ll find will be at 18 mg/ml, for high-PG blends. For the reasons stated above, high-VG blends will have a significantly lower nicotine concentration, usually maxing out at 6 mg/ml, or maybe 9 mg/ml if you’re looking hard enough.

Most regular smokers looking to quit using e-cigarettes tend to start at around 12 mg/ml with a 50-50 PG/VG blend and then tweak their preferences based on how they feel moving forward.

Nicotine-free e-liquids

You may have noticed that a significant number of e-liquids out on the market have no nicotine in them at all. You may have also noticed that a large proportion of these nicotine-free e-liquids are sold in much larger bottles than your standard nicotine-containing e-liquid bottle.

So what gives?

In the UK, nicotine can only be sold in containers up to 10 ml at a time. That’s why even nicotine shots come in small bottles. So if you’re a frequent vape user, you might find yourself carrying around a number of bottles everyday. You’ll also wind up buying many more bottles at a time than otherwise.

These no-nicotine e-liquids are the answer to this vaping dilemma. Since it’s nicotine-containing e-liquids that are regulated in size, many e-liquid manufacturers have decided to release nicotine-free (that is, unregulated) versions of their e-liquid, and allow people to add nicotine on their own. These are called shortfills, since they’re not filled all the way to the top of the bottle, to allow vape users to add their own nicotine.

Adding a full 10ml of 18 ml/mg nicotine shot to a 50 ml nicotine-free e-liquid, for example, results in a 60 ml bottle of 3 mg/ml e-liquid. Over time, this winds up being a lot cheaper (and a lot friendlier to the environment) than purchasing 6 comparative 10 ml plastic bottles.

The downside to this is that you need a lot of nicotine to get a shortfilled e-liquid up to significant strength. Even just getting a 9 mg/ml-strength shortfill would take equal parts nicotine and shortfill, which would just wind up diluted and weak-flavoured.

For that reason, most shortfills you’ll find are high-VG. This means that you can add a reasonable amount of nicotine (up to either 3 mg/ml or 6 mg/ml strength), and let the battery and the coil make up for the low nicotine concentration. If you’re producing enough vapour, and if you had big enough lungs and a powerful enough coil, you could get a nicotine rush from 1 mg/ml if you wanted. Unfortunately, human lung capacity and current battery safety regulations make this not only unprobable, but probably unpleasant.

Stick with the shortfills.

Vaping without nicotine at all

Yeah, it happens. Some people find that vaping 0 mg/ml is a great way to get a fix for their sweet tooth without the obvious health concerns of consuming two or three metric tonnes of Skittles.

Nicotine and darker e-liquid

If you are vaping with nicotine, however, you may notice that your e-liquid starts to get a little darker over time. Similarly, you’ll find that higher-nicotine blends are darker than lower-nicotine blends of the same flavour. This has to do with nicotine oxidisation, which can occur when nicotine is exposed to heat, sunlight, or plain old time.

Within reason, this shouldn’t affect the experience of vaping the e-liquid. After a little while, however, enough of the nicotine will have oxidised that the effective strength of the e-liquid will be diminished; that is to say, your 6 mg/ml e-liquid will only feel to you like a 3 mg/ml e-liquid. This can happen as soon as a year after purchase, for some higher-strength e-liquids.

After too much oxidisation, you’ll probably want to avoid the e-liquid entirely, as it has probably expired.

E-liquid expiration

Most e-liquids have a shelf life of 1-2 years, which is impressive considering that e-liquids are food-grade. This limit is mostly based on the shelf life of freebase nicotine, which, with time, will gradually oxidise, lose strength, and go bad.

E-liquid without nicotine may fare a little bit better. PG and VG are very stable compounds and can last much longer than 2 years if stored correctly. In the case of nicotine-free e-liquid, your limiting factor will be the shelf life of the flavourings. Some sweeter flavours may go bad around the same time as nicotine, after a year or two; some may expire after much longer, lasting 4 or even 5 years before you find yourself vaping totally flavourless e-liquid.

As time passes and a bottle of e-liquid gets older and older, you might notice that the flavours taste a little different or that the vapour tastes stale. You might even notice ingredient separation, where the heavier VG settles out of the thinner PG, with the water and flavourings sitting at the top and bottom.

Hopefully you never have to find out.

Too much exposure to sunlight or heat will dramatically reduce the shelf life of a bottle of e-liquid. Not only will it break down the nicotine much faster, but heat will mess with the composition of the flavourings. Try not to leave your e-liquid sitting in cars on too many hot days. Instead, keep e-liquids in cool, dark places, like inside cupboards—preferably out of the reach of children.

If you do find yourself the unlucky owner of a bottle of expired e-liquid, however, don’t pour it down the drain. Whatever nicotine that might still be in the e-liquid will get into the water supply and, even at tiny concentrations, will start messing with your local ecosystem. We don’t want nicotine-addicted fish in our lakes. Instead, consider wiping it up with kitchen roll, or better, using kitty litter to absorb any spilled e-liquid. Litter has the added bonus of neutralising smells so your rubbish won’t smell like cupcakes or strawberry milkshakes.

If in doubt about a bottle of e-liquid, it’s probably best to just bin it. Expired e-liquid is actually in a lot of ways less toxic than non-expired e-liquid, but it’s just bad karma to keep it around.

Wait hold on, are e-liquids toxic?

As in all things, the poison is in the dose—but yes, e-liquids can be toxic. Consuming large amounts of PG or VG on their own is bound to give you an upset stomach, but nicotine is what you especially need to look out for.

When you vape nicotine, you’re inhaling a pretty small amount of e-liquid, and a lot of the nicotine in the vapour actually gets exhaled when you blow the vapour out. If you were to drink pure e-liquid, however, all of that nicotine is going straight into your stomach, and a much, much higher doses. Even at a low dosage, it can make adults very sick and it can kill younger children. For that reason, always keep your nicotine secure and out of reach. The flavours and colours can be enticing to children.

As a heads up, vaping and drinking nicotine isn’t the only way that nicotine can get into your system. Nicotine can also permeate your skin, which means that just touching e-liquid can give you a nicotine rush. (This is essentially how the nicotine patch works, which makes sense if you think about it.) For this reason, make sure to wear gloves when cleaning up nicotine spills, and clean the area thoroughly so that other people (or pets) don’t wind up accidentally consuming a little bit of nicotine when touching the area later.


All of that being said, modern e-liquids are extremely safe if used according to the instructions on the packaging. While tabloid media likes to stir panic by claiming that e-liquids contain antifreeze or that they’ll give you some horrible disease called ‘popcorn lung’, these are myths based on obsolete rumours and misunderstood science.

In fact, earlier this year, Public Health England issued an evidence review on the effects of vaping and found it to be ‘95% safer than smoking tobacco.’ We’re working every single day to chisel down on that last 5%, but in the meantime, consider the approval of a government body the best stamp of safety you’re likely to see.

At Vapour, we only sell TPD-compliant e-liquids made from pharmaceutical-grade ingredients. All of our e-liquids are 100% diacetyl free and use the best freebase nicotine we could find (and we looked).


Look. This is getting on to 2500 words, and you and we both have better things to do than listen to us go on for another 2500 words. (Which, for the record, we could do, since we’re so bonkers about e-liquid that we actually went into the e-liquid business.) But another 2500 words wouldn’t get you any closer to the actual experience of vaping a good solid e-liquid.

So now that you’re basically an e-liquids guru, why don’t you get out there and try some out for yourself? We realise we have a bit of a bias, but our very own 50-50 line is really superb.

Chris Polenski
Chris Polenski