Vape Guide
How to Mix a Longfill: Quick & Easy Step-by-Step Guide
A longfill lets you build a 120ml bottle of e-liquid from three separate components: a 30ml flavour shot, an 80ml VG bottle, and a 10ml nicotine shot. Buying the parts separately costs less than a pre-mixed 120ml because VG and flavour concentrates aren't taxed as finished e-liquid — so you pay less vape tax while getting more juice. Mixing takes less than two minutes.
What you need
Your mixing kit
- 1 × 120ml longfill bottle (with the 30ml flavour shot already inside)
- 1 × 80ml VG (Vegetable Glycerine)
- 1 × 10ml Nicotine Shot
- A bottle-opening tool or pliers to remove the nozzle cap
How to mix — step by step
- Open the longfill bottle. Use a bottle-opening tool or pliers to pop off the nozzle cap on the 120ml bottle. This gives you access to pour in the other components. The bottle already contains the 30ml flavour shot.
- Pour in the 80ml VG. Open your VG bottle and carefully pour the entire 80ml into the longfill bottle. VG is thick — take your time and tip slowly to avoid spills. You'll now have 110ml total in the bottle.
- Add the nicotine shot. Open your 10ml nic shot and squeeze the full contents into the bottle. This brings you to 120ml total at approximately 1.5mg nicotine strength.
- Seal and shake. Push the nozzle cap back firmly until it clicks. Shake thoroughly for 30–60 seconds to blend the flavour, VG, and nicotine fully.
Let it steep for best results. After mixing, leaving the bottle in a cool, dark place for a few days allows the flavour to fully integrate. You'll notice a richer, more rounded taste after steeping compared to vaping it immediately.
Why longfills save you money
| Component | Taxed? | Notes |
|---|---|---|
| Pre-mixed 120ml e-liquid | Yes — per ml | Full vape tax applies on every ml |
| 30ml flavour concentrate (longfill) | Yes | But only taxed on 30ml, not 120ml |
| 80ml VG | No | VG alone is not a finished e-liquid |
| 10ml Nicotine Shot | Yes — per ml | Only 10ml taxed, not the full volume |
Storing your mixed juice
Storage tips
- Store in a cool, dark place away from direct sunlight — heat and UV degrade nicotine and flavour faster
- A cupboard or drawer works well; a fridge is even better for long-term storage
- Keep the cap closed tightly between uses — air exposure oxidises nicotine
- Shake well before each refill — VG and flavour can separate slightly over time
Frequently asked questions
What nicotine strength does a longfill give you?
Using a standard 10ml nic shot (18mg/ml) in a 120ml longfill gives you approximately 1.5mg/ml in the final mix. If you want higher strength, use a stronger nic shot or add two nic shots — but adjust the VG volume accordingly to stay at 120ml total. Most vapers who've switched from cigarettes find 1.5–3mg in a sub-ohm or RDL device works well.
Do I need to steep my longfill before vaping it?
Not strictly — you can vape it immediately after mixing. But steeping for 2–7 days makes a noticeable difference, especially on fruit and dessert flavours. The flavour molecules from the concentrate need time to fully bind with the VG and nicotine. Fresh-mixed longfills often taste slightly thin or sharp; the same juice after a week tastes significantly fuller and more rounded.
What's the difference between a longfill and shortfill?
A shortfill is a pre-mixed, nicotine-free 50ml or 60ml e-liquid in a 60ml or 100ml bottle — leaving room to add a nic shot yourself. A longfill is a concentrated flavour shot (typically 30ml) in a larger 120ml bottle, to which you add both VG and a nic shot separately. Longfills give you more flexibility and a larger final volume, while shortfills are slightly simpler to mix since the flavour-to-VG ratio is already done for you.
Can I use PG instead of VG in a longfill?
Yes, but most longfill recipes are designed for Max VG (or high-VG) mixing. Adding PG will thin the liquid and increase throat hit — some vapers prefer this, especially for MTL devices. If you want a 70/30 VG/PG ratio, substitute some of the VG with PG. Krem stocks both VG and PG separately if you want to blend to a specific ratio.
