What Is A Longfill Vape Liquid?
A clear UK guide to longfill e-liquid, how the concentrate plus base model works and how it differs from shortfill bottles.
Longfills are concentrated flavour bottles you mix with VG/PG base and a nic shot at home.
Where shortfills come pre mixed with the base, longfills give you the flavour concentrate separately. You buy the bottle which is roughly one third full of flavour, add base liquid, then add a nic shot if you want nicotine. Final volume is typically 60ml or 100ml after full mixing.
Longfills are the most flexible e-liquid format for UK vapers willing to do a bit of mixing. They cost less per ml than shortfills, give you more control over the final ratio and let you scale your favourite flavours. Understanding how longfills work opens up significant cost savings.
How longfills differ from shortfills
Four key differences shape the choice. The grid below covers each.
Concentrate only
Longfills contain only flavour concentrate, not base. You add the VG/PG yourself.
✓ DIY mixingBuy base separately
VG and PG bases are sold separately by UK vape shops. You choose your ratio.
✓ CustomisableLower per ml cost
Longfills work out roughly 30 to 40 percent cheaper per ml than shortfills.
✓ Cost savingMore mixing
Each longfill needs more steps than shortfills. Worth it for regular flavours.
⚠ More effortThe longfill mixing process
The table below covers the standard longfill mixing process for UK vapers.
| Step | What to do |
|---|---|
| 1. Buy longfill concentrate | Choose flavour and bottle size from UK vape shop |
| 2. Buy VG/PG base | Match desired ratio. 70/30 VG/PG is common for sub ohm |
| 3. Buy a nic shot if needed | 10ml 18mg shot for nicotine vapers |
| 4. Add base to bottle | Fill to the 60ml or 100ml line on the longfill bottle |
| 5. Add nic shot | Top up with the shot if you want nicotine |
| 6. Shake and steep | Vigorous shake plus 24 to 48 hours steeping for best results |
Why longfills give better cost per ml
A typical UK 60ml longfill costs 10 pounds. Adding a 30ml base bottle (5 pounds) and a nic shot (1 to 2 pounds) gives you 60ml of finished e-liquid for around 16 to 17 pounds. The same 60ml as a shortfill plus shot would cost roughly 25 pounds. Saving around 8 pounds per 60ml adds up significantly for regular vapers using 100ml or more per week.
Longfills require steeping for best flavour, typically 24 to 48 hours after mixing. Some flavours benefit from longer steeping up to a week. Shake the bottle daily during steeping. The flavour intensity improves significantly compared to vaping straight after mixing. UK longfill enthusiasts often have several bottles steeping at different stages to maintain a steady supply.
How to choose longfills successfully
The checklist below covers what UK vape shop staff most often recommend.
Longfill selection checklist
Use four or more of these for satisfying longfill mixes.
- Stick to brands you know after testing in shortfill or 10ml form
- Match base VG/PG ratio to your device requirements
- Buy base in larger bottles for better per ml cost
- Steep for 24 to 48 hours for full flavour development
- Label bottles with mix date and contents for tracking
- Start with one longfill before stocking up to test the workflow
Are longfills right for you
Longfills work well for UK vapers willing to do small amounts of mixing in exchange for cost savings. They suit regular sub ohm users who go through 100ml or more per week. They are less suitable for occasional vapers, MTL users wanting smaller bottles or anyone who finds the mixing workflow frustrating. Trying one longfill alongside your usual shortfill is the simplest way to see if the format suits you.
Longfills sit alongside other e-liquid formats, which our our guide on what is a shortfill vape liquid covers, plus our article on what are nic shots explores the science behind base ratios.
Frequently asked questions
Are longfills cheaper than shortfills?
Yes typically 30 to 40 percent cheaper per ml of finished e-liquid.
How much base do I need for a longfill?
Match the bottle size. A 60ml longfill needs around 30ml of base plus a nic shot.
Can I make a longfill last longer?
Sealed concentrate lasts 18 to 24 months. Once mixed, store cool and dark for up to 12 months.
Do I have to steep longfills?
Strongly recommended. Steeping for 24 to 48 hours significantly improves flavour.
Are longfills only for sub ohm vapers?
No but the format suits them best because of the typical 70/30 VG/PG mixing ratio.
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