Longfill Booster Kits Explained: Your Complete Mixing Guide
If you're new to longfills, you might be wondering what booster kits are and why you need them. The short answer? They're the missing piece that transforms your concentrated longfill into ready-to-vape e-liquid.
Here's everything you need to know about longfill booster kits, how they work, and which one to choose.
What Is a Longfill Booster Kit?
A longfill booster kit contains four 10ml bottles that you add to a 20ml longfill concentrate to create a full 60ml of finished e-liquid. Each kit is pre-calculated to deliver a specific nicotine strength and VG/PG ratio when mixed correctly.
Think of it as a recipe in a box—everything you need is included, measured out, and ready to combine with your chosen flavour.
What's Inside a Booster Kit?
Depending on the strength and ratio you want, a booster kit typically contains:
- Nicotine shots (freebase or nic salts) at various strengths
- VG boosters (vegetable glycerin) for cloud production
- PG boosters (propylene glycol) for flavour and throat hit
The exact combination varies based on your target nicotine strength and preferred VG/PG ratio.
Freebase vs Nic Salt Booster Kits
You'll see two main types of booster kits available:
Freebase Nicotine Boosters
- Deliver a stronger throat hit
- More noticeable at higher strengths (6mg+)
- Traditional vaping experience
- Ideal for sub-ohm and DTL (direct-to-lung) vaping
Nicotine Salt Boosters
- Smoother throat hit, even at higher strengths
- Faster nicotine absorption
- Perfect for MTL (mouth-to-lung) devices
- Great for pod kits and pen-style vapes
Which should you choose? If you want a classic vaping sensation with a pronounced throat hit, go freebase. If you prefer smooth, satisfying hits at higher strengths, choose nic salts.
Available Booster Kit Strengths
We stock Ohm Boy booster kits in multiple strengths to suit every vaper:
3mg Freebase Booster Kit
- Final strength: 3mg nicotine
- VG/PG ratio: 70/30
- Best for: Sub-ohm tanks, cloud chasers, DTL vaping
- Creates: 60ml of smooth, high-VG e-liquid
6mg Freebase Booster Kit
- Final strength: 6mg nicotine
- VG/PG ratio: 50/50
- Best for: MTL devices, pod kits, all-day vaping
- Creates: 60ml of balanced e-liquid
10mg Nic Salt Booster Kit
- Final strength: 10mg nicotine
- VG/PG ratio: 50/50
- Best for: MTL pods, recent switchers, moderate nicotine needs
- Creates: 60ml of smooth, satisfying e-liquid
12mg Freebase Booster Kit
- Final strength: 12mg nicotine
- VG/PG ratio: 50/50
- Best for: Heavy smokers, tight MTL devices
- Creates: 60ml with a strong throat hit
14mg Nic Salt Booster Kit
- Final strength: 14mg nicotine
- VG/PG ratio: 50/50
- Best for: Maximum nicotine satisfaction, heavy users
- Creates: 60ml of high-strength, smooth e-liquid
- Contains: 4 x 20mg nic salt shots
How to Use a Longfill Booster Kit
Mixing a longfill with a booster kit is straightforward. Here's the step-by-step process:
Traditional Method (Pouring)
- Remove the cap from your 20ml longfill bottle
- Open all four 10ml booster bottles
- Pour each booster into the longfill bottle
- Replace the cap on the longfill
- Shake vigorously for 30–60 seconds
- Your 60ml e-liquid is ready to vape
Mess-Free Nib Method (Recommended)
Many modern booster kits feature a clever nib design that eliminates spills:
- Twist off the caps from all four booster bottles and your longfill
- Keep the longfill upright
- Place the nib of a booster bottle over the longfill nib
- Turn the booster bottle upside down
- Gently squeeze and release the longfill bottle—the vacuum will draw the liquid in
- Repeat for all four boosters
- Replace the cap and shake well
This method is slower but guarantees zero mess and no wasted liquid.
Why Use Booster Kits Instead of Individual Shots?
You might wonder why you can't just buy individual nicotine shots and VG/PG separately. You can—but booster kits offer several advantages:
- Pre-calculated ratios – No guesswork, no math, no mistakes
- Guaranteed results – Every kit produces the exact strength and ratio advertised
- Convenience – Everything you need in one package
- Cost-effective – Often cheaper than buying components separately
- Beginner-friendly – Perfect if you're new to DIY mixing
Which Booster Kit Should You Choose?
Here's a quick guide based on your vaping style:
| If you vape... | Choose this kit |
|---|---|
| Sub-ohm tanks, want big clouds | 3mg Freebase (70/30 VG) |
| MTL pods, moderate nicotine | 6mg Freebase or 10mg Nic Salt (50/50) |
| Tight MTL, strong throat hit | 12mg Freebase (50/50) |
| Heavy user, smooth high strength | 14mg Nic Salt (50/50) |
Booster Kits and the UK Vape Tax
With the UK vape tax applying to finished e-liquids, booster kits paired with longfills offer a smart way to reduce costs. Because you're mixing at home, you're only paying tax on the concentrated flavour—not the full 60ml volume.
This makes booster kits an essential part of cost-effective vaping in 2026 and beyond.
Top Tips for Using Booster Kits
Always use all four bottles – The kit is designed as a complete set; using fewer will throw off the strength and ratio
Shake thoroughly – Proper mixing ensures consistent flavour and nicotine distribution
Check compatibility – Booster kits are designed for 20ml longfills that create 60ml when mixed
Store properly – Keep unused boosters in a cool, dark place away from children and pets
Label your bottles – Once mixed, write the strength and date on the bottle
Ready to Start Mixing?
Longfill booster kits take the complexity out of DIY e-liquid mixing. Whether you're chasing clouds with a 3mg freebase kit or need the smooth satisfaction of a 14mg nic salt blend, there's a booster kit that's perfect for your setup.
Shop our full range of Ohm Boy booster kits and pair them with your favourite longfill flavours for a customized, cost-effective vaping experience.
Questions about which kit to choose? Get in touch—we're here to help you find your perfect match.