How to Mix a Longfill Bottle Step by Step
How to mix
a longfill bottle
step by step
A practical UK walkthrough of the four-step longfill method. No maths, no syringes, no measuring cups. Just four actions that turn a half-full 60ml bottle into ready-to-vape e-liquid at the strength you picked.
Four steps from bottle to tank. Open the 60ml longfill by unscrewing the cap plus pulling out the dripper nib. Pour every drop of the three 10ml Mixer Kit bottles into the longfill bottle. Seal the cap tight plus shake vigorously for one full minute. Rest for fifteen minutes for fruit or menthol flavours plus 24 to 48 hours for dessert or tobacco flavours in a cool dark cupboard. Your 60ml of ready-to-vape e-liquid is finished.
Three numbers
that run the whole process
If you remember three numbers you will never mis-mix a longfill. Everything else is just pouring plus shaking.
Steps total
Open, pour, shake, rest. Four actions, no tools beyond the bottles already in the box.
Mixer bottles
Every Mixer Kit contains exactly three 10ml bottles. All three go in. Nothing extra.
Shake time
One full minute of vigorous shaking is the minimum for a uniform mix without streaks.
Mixing a longfill is deliberately simple. Here is every action explained.
A longfill looks intimidating the first time you pick one up. A 60ml bottle half-filled with concentrate plus three tiny shot bottles feels like the start of a chemistry project. It is not. The whole format is designed so an adult with no DIY experience can finish the mix in under three minutes with nothing more than their hands plus a clean worktop.
The reason it works is that the maths is already done. A 60ml bottle contains exactly 30ml of concentrate. A Mixer Kit contains exactly three 10ml bottles which add up to the remaining 30ml. You do not need to measure anything. You pour every drop of all three bottles in, seal the cap plus shake. The finished e-liquid is already at the strength printed on the Mixer Kit box because the system was built around that number.
What can go wrong is skipping steps. The two most common mistakes are leaving the shake too short and not pouring every drop out of the Mixer Kit bottles. Both create an unbalanced mix. The shake is the easiest fix: time one full minute on your phone. The pour is about patience: squeeze each small bottle for an extra few seconds to get the final millilitre out.
What if I want a different strength than the kit?
Change the kit, not the method. Every longfill flavour pairs with multiple Mixer Kits at different strengths plus VG/PG ratios. A Nixer 9mg Freebase 50/50 uses the same four-step method as a Nixer 3mg Freebase 70/30. Only the strength on the Mixer Kit box changes. If you are ever tempted to add an extra shot from a third-party brand to boost the strength, do not. That route pushes you over the UK legal cap of 20mg/ml plus wrecks the flavour balance.
- Step 1: Open. Unscrew the cap plus remove the dripper nib.
- Step 2: Pour. Empty every drop of all three Mixer Kit bottles into the longfill.
- Step 3: Shake. Reseal plus shake for one full minute.
- Step 4: Rest. Fifteen minutes for fruit or menthol. 24 to 48 hours for dessert or tobacco.
From sealed box
to first vape
Each step includes what to do plus the one thing most first-time users get wrong.
Unscrew the cap plus pull the nib
Take the 60ml longfill bottle and unscrew the child-proof cap. Under the cap sits a dripper nib pressed into the bottle neck. Pinch it between thumb plus forefinger (or use the clean end of a pen) to pull it out entirely. The bottle opening should now be fully clear. Set the nib plus cap to one side on a clean worktop.
Empty all three Mixer Kit bottles
Take the first 10ml Mixer Kit bottle, unscrew its cap plus squeeze every drop into the longfill. Squeeze the bottle flat for an extra three seconds to get the last millilitre out. Repeat with bottles two plus three. The order does not matter but do not skip any. All three go in. You should see the liquid level in the longfill rise close to the neck when you are finished.
Reseal plus shake for one full minute
Push the dripper nib firmly back into the bottle neck until it clicks. Screw the child-proof cap down tight. Hold the bottle in one hand and shake it vigorously for a full sixty seconds. Set a timer on your phone. VG is thick plus takes real effort to distribute. The bottle should look uniform in colour when you hold it up to the light, with no streaks or layers visible.
Let it rest before filling your tank
How long depends on your flavour. Fruit plus menthol blends are usually excellent within fifteen minutes of finishing the shake. Dessert, custard plus tobacco flavours genuinely benefit from 24 to 48 hours in a cool dark cupboard so the richer notes can meld together. Once rested, fill your tank or pod as normal. The bottle will keep for roughly 30 to 60 days in a dark cupboard.
The full mixing
checklist
No special tools. No scales. No syringes. If you can pour a cup of tea you can mix a longfill.
Six items, all standard
Pick your flavour
plus a matched Mixer Kit
Every Nixer longfill page lists its compatible Mixer Kit next to the buy button. Pick the flavour you want plus the strength you need, add both to the basket plus follow the four steps above when it arrives.
The quickest way to avoid mixing headaches is to use a system that was designed around the four-step method in the first place. The full Nixer longfill range pairs every flavour with its recommended Mixer Kit at your chosen strength so the only decision is which flavour to try next.
Good mix vs
bad mix
A clean reference for what a properly mixed longfill looks plus tastes like compared with a rushed one.
What it should look like
- ✓All three Mixer Kit bottles fully emptied with no pooling at the bottom of any shot bottle.
- ✓Full 60ml in the longfill bottle with the level sitting just below the neck.
- ✓Shaken for a full 60 seconds until the liquid looks uniform colour held up to the light.
- ✓Smooth clean throat hit on the first puff with no harsh edges.
- ✓Flavour matches the label with all the notes in the right places.
Warning signs it went wrong
- ✗Residue left in the Mixer Kit bottles meaning you left 3 to 5ml of base behind.
- ✗Short fill in the longfill bottle with obvious empty space below the neck.
- ✗Streaks visible in the bottle held up to the light after shaking.
- ✗Harsh peppery throat hit from a pocket of undispersed nic shot.
- ✗Thin or chemical flavour that does not match the bottle label.
For the wider picture on longfills including the format itself, strength selection plus flavour steering, head to our full Nixer vape review hub where every major question UK longfill users ask is covered in its own article.
Back to the Nixer Vape Review hub
This article is one chapter in our complete Nixer knowledge base. Head back for the full index covering longfill basics, strength, steeping, flavours plus every Mixer Kit variant.
More on longfills
& mixing
If you want the background on why longfills exist in the first place, our guide on what is a longfill and how does it work explains the UK format plus why it saves money. For the Nixer-specific mixing walk-through which includes the exact Mixer Kit instructions, head to how to mix Nixer longfills with the Nixer Mixer Kit. Plus if you want the detail on the shots themselves, our explainer on what nicotine shots you need for a longfill covers the options across freebase and nicotine salt.