What Are Longfills and How Do I Vape Them?

The New Approach To DIY E-Liquid.
By Josh, Head Of Content
19th Jun 2024

A popular option in Europe for some time, Longfill e-liquids are now being embraced by UK vapers. But, what are they and how do they work? You’re in the right place to find out! This guide will take you through exactly what they do and why they might be the perfect replacement for your favourite e-liquids.

What Are Longfills?

A longfill is a large, underfilled bottle of flavour concentrate. This concentrate is what gives e-liquid its distinctive taste, whether that’s fruit, menthol, tobacco or any of the myriad flavours available. It needs to be diluted and turned into a vape juice using VG, PG and nicotine – this is where you come in. Each longfill has room for you to add extra VG and PG, as well as nic shots to create your desired strength.

Longfill brands

Longfills are the ideal product for vapers who want to give e-liquid mixing a go but don’t necessarily want to deal with the work and cost that normally comes with it. Not to mention the amount of time it can take for homemade liquid to “steep” to the point where it becomes suitable for vaping.

How Are Longfills Different To Shortfills?

Longfills are essentially a hybrid product, they combine the simplicity of shortfills with the flexibility of DIY concentrates. Like shortfills, a longfill is an underfilled bottle that you add extra liquid to. However, unlike shortfills, the liquid already inside your bottle is a flavour concentrate suspended in PG rather than a 0mg vape juice.

Longfill bottle content Shortfill bottle content

This difference is very important, because it means that while vapers are tied to whichever VG/PG ratio a shortfill arrives in – that’s not the case with longfills. You can easily make a 50/50, 70/30 or high PG e-liquid from the same bottle depending on which shots you add.

The same can be said for nicotine strength, as while you’ll struggle to create e-liquid in a strength higher than 3mg when using a shortfill – you can create a 20mg vape juice using a longfill with relative ease.

Unlike shortfills, which can be vaped without the addition of a nic shot, you can’t vape a pure longfill. It’s not dangerous to vape just flavour concentrate but it’s certainly not recommended, pure concentrate will taste very rough and will clog up your coils – it’s the equivalent of drinking undiluted squash.

How Do I Turn My Longfill Into E-Liquid?

Turning a longfill into an e-liquid will require the purchase of two or three extra products. Namely, VG / PG and nic shots, alongside a measuring cylinder or two. Essentially, you’ll need to use this combination of three liquids to create an e-liquid that has your desired VG/PG ratio and nicotine strength, and the jugs to make sure you’re using the right quantity.

A 60ml of lonfill liqud, a bottle of 100% VG, a bottle of 100ml PG, two 10ml nicotine shots and a measuring cylinder

The concentrate inside your longfill is suspended in 100% PG. The extra liquid that you add to top up the bottle will alter this percentage and, in turn, create an e-liquid that features a VG/PG concentration you prefer. You also need to factor in your nicotine shots, as not only do you need to add the right amount to ensure the correct strength is created, but they also have a VG/PG concentration of their own.

How To Set-Up And Use A Longfill:

Remove caps and nibs from all bottles
Remove caps and nibs from all bottles
Measure and pour VG and PG into mixing cylinder
Measure & pour VG and PG into mixing cylinder
Add the VG and PG mix into your longfill
Add the VG and PG mix into your longfill
Add the nic shots into your longfill
Add the nic shots into your longfill
Re-insert nib and re-attach lid to your longfill
Re-insert nib and re-attach lid to your longfill
Shake well to mix contents
Shake well to mix contents

Do I Need To Steep A Longfill?

Traditional DIY e-liquids need some time to mature to help bring out the best flavour and make sure the VG and PG have properly bonded with the flavour concentrate. This process, known as Steeping, can take anywhere from a couple of days to a couple of weeks. Most longfills don’t require this extra step. However, some vapers report that they get a better flavour from their e-liquid after letting it mellow for a few hours or days. Our selection can be vaped straight away.

Longfill Mixing Examples

That’s enough theory, let’s put it into practice. We’ll use the Bar Salt Longfills by Vampire Vape as an example. Available in 60ml bottles each one contains 10ml of flavour concentrate, which means we have to use 50ml of liquid to turn it into an e-liquid and properly dilute the concentrate.

In this example, we’re going to create a 10mg, 50/50 e-liquid. To do so we’ll need to add 5ml of PG, 15ml of VG and three 50/50, 20mg nic shots. If this doesn’t quite sound right, remember, the concentrate inside is suspended in 100% PG. So, what you’re actually combining is:

50/50 mix result 10mg, 20ml nic shot, 15ml 100%VG, 5ml 100%PG, 10ml Concentrate 100%PG

Looking at the above combination it’s pretty easy to see how we’ve managed to create 50/50 VG/PG e-liquid. Follow the above and you’ll have a medium-strength vape juice perfect for MTL vaping. But, what if you want something a little thicker that’s a better fit for DTL vaping? Let’s have another go.

In this example, we’re going to create a 70% VG, 3mg e-liquid using Bar Salt Longfills. You’ll need to add 35ml of VG, 5ml of PG and one 70/30, 18mg nic shot. Here’s what you’re actually combining:

70/30 mix result 3mg, 10ml nic shot 70/30, 35ml 100%VG, 5ml 100%PG, 10ml Concentrate 100%PG

Once you’re finished adding your ingredients, you’ll end up with an e-liquid that creates enough vapour to keep up with any shortfill and will satisfy your nicotine cravings.

Longfills And Mixer Packs

There is an easier way if you’re new to longfills or can’t stand maths, some longfills come with mixer packs.

Nixer have produced a series of longfills alongside specially designed Mixer packs. These packs are available in varieties that can be used to create a low-strength high VG e-liquid or stronger 50/50 e-liquid in your choice of freebase or salt nicotine. Just pour the bottles in the Mixer pack straight into your longfill, give it a shake and you’re ready to go.

Nixer longfill and three mixer bottles

Some brands take things further and actually include flavoured mixers to use with their longfills. Options like Imp Jar longfills include an underfilled bottle of concentrate and three standard 10ml e-liquids. This range is ideal if you’re looking for a really strong flavour.

How To Hack Longfills

With a little outside the box thinking you can hack a longfill without relying on mixer packs or scribbled-down formulas! You just need to be a little loose about the exact VG/PG ratio and nic strength you want to vape. In terms of materials, all you need is a longfill and a lot of nic shots.

Let’s use Element longfills as an example. Each 250ml bottle contains 50ml of e-liquid, so you’re going to need twenty 10ml nic shots to fill up the bottle. In this example we’re going to use 20mg nic shots.

Using just nic shots removes the need for extra VG and PG and really cuts down on calculation time. Adding all twenty to the bottle will create a 16mg e-liquid. If you want to do the maths, it’s as follows:

4000 / 250 = 16

This process took us around 20 minutes and the e-liquid was ready to vape straight away. Just make sure you give your longfill a good shake, for around 3-5 minutes.

This isn’t necessarily the prettiest way to create an e-liquid, however, a quick cost calculation means you’ve created 250ml of high-strength, MTL-friendly e-liquid for about £35, with very little effort. The equivalent in premixed Element e-liquid (10ml, 50/50 bottles) would cost more than double that. The VG/PG concentration of this particular mix sits at around 54% PG / 46% VG.

You’re unlikely to find a 16mg, 54% PG e-liquid on the shelves, however, in terms of effect, it’s very similar to the 20mg, 50% VG e-liquids that you find everywhere.

You can perform this same hack with nic shots in any strength and VG/PG ratio. Use an 18mg shot to create a 14.4mg e-liquid or 9mg shots to create a 7.2mg e-liquid for a really light vape. Just remember to keep an eye on the VG/PG ratios of your nic shots as twenty of them will radically alter the final concentration of your e-liquid.

Longfills Pros and Cons

As you’ve probably guessed by now, longfills are definitely a unique option. But, are they the right fit for you? They can be tricky to get used to, but the opportunity to make your own e-liquid opens up a path to saving money – and when is this not important? Here are our pros and cons to help make weighing things up a little easier.

Longfill Pros

Can Be Cheaper

Perhaps the strongest plus point for these products is that they can work out remarkably cheaper than stand bottles, particularly, 50/50 and high PG juices. With a little practice you’ll be cranking out a month’s supply of e-liquid in no time!

Simpler Than Traditional DIY Concentrate

E-liquid mixing isn’t by any means a new skill, DIYers have been at it since vaping’s inception. However, traditional mixing required a lot of materials and a lot of time. Longfills are much closer to shortfills, in that you can add your liquid, shake it and vape.

More Flexible Than Shortfills

Shortfills contain a ready-made e-liquid that just needs nicotine, but due to the limitations on nicotine strength in the UK (20mg/ml), it’s very difficult to make anything higher than 3mg. Longfills don’t suffer this limitation, there’s more room in the bottle and this means more opportunity for customisation.

Longfill Cons

Longfills Can Be Complicated

The biggest issue related to longfills is their complexity, there’s no getting around it – they’re not the simplest way to vape. This isn’t always a problem; a lot of people experience satisfaction making things themselves. But, if you’re just starting out, we recommend you keep things as easy as possible, and this means ready-mixed e-liquids in most cases.

Leftover VG/PG

Unless you’re using our hacking method (we’re really proud of that one) you’re going to have to buy a fair amount of VG and PG and this is because they’re sold in larger bottles, normally 500ml and sometimes 1L. That’s great in some ways as it means you won’t have to buy it very often, but it also means you're going to have to find space for it and throw it away if it goes out of date.

Big Bottles Aren’t Always Convenient

Inventions such as the humble hip flask have taught us that bigger isn’t always better. While it’s certainly cost-friendly to be able to create 250ml of e-liquid in a few minutes, it can prove to be a little unwieldy for the vaper on the go. Yes, you could decant your e-liquid into smaller 10ml bottles but this does seem like a lot of hassle.

Need More Help With Longfills?

There’s certainly a lot to learn when it comes to mixing your own e-liquid, whether that’s with DIY kits or longfills. If you’re looking to stock up on the ingredients and tools you need for longfills, make sure you check out our DIY Mixing range that features VG, PG, extra bottles and other useful tools.

As always, if you’re looking for one-to-one assistance, have a couple of questions or just want a recommendation on what’s the best longfill: talk to the experts. Our Customer Service Team are all vapers and are ready to help seven days a week. You can contact them via phone, email and even live chat.

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