DIY E-Liquid Mixing Guide | Ireland Technical Reference

Safety Warning (Read First)

This guide is intended for adults aged 18+. Nicotine is a toxic substance.

Always wear nitrile gloves and protective eyewear when handling nicotine.
Work on a clean, stable surface away from food preparation areas.
Keep all ingredients, especially nicotine, out of reach of children and pets.
If nicotine comes into contact with skin, wash immediately with soap and water.

What DIY E-Liquid Mixing Is

DIY e-liquid mixing is the controlled process of combining a base liquid (VG/PG), flavour concentrates and optional nicotine to produce a finished vaping liquid with a defined composition.

Accurate measurement and correct volume calculations are essential. Mixing “by eye” or “by drops” is unsafe and unreliable.

Required Tools (Accuracy Standard)

1 ml syringe – for flavour concentrates
10–20 ml syringe – for VG/PG base
OR digital scale with 0.01 g precision
Empty bottles with secure caps
Nitrile gloves and paper towels

Sanitation note: Use new bottles or properly cleaned/sterilised bottles to reduce contamination risk and improve repeatability.

Related reference: flavour concentrates overview: EirHorse Flavors & Concentrates

Total Volume Logic (Critical Rule)

The final volume must always equal the bottle size.

Base volume = Target volume − (Flavour volume + Nicotine volume)

DIY volume calculation examples — correct total-volume logic

Target bottle	Flavour	Nicotine	Base required
60 ml	9 ml (15%)	10 ml	41 ml
100 ml	12 ml (12%)	0 ml	88 ml

Nicotine Reference (18 mg/ml shot → target strength)

Quick reference for common mixes using 18 mg/ml nicotine shots. Calculation rule: Nicotine volume = (Target mg/ml × Total ml) ÷ 18.

Nicotine shot reference — 18 mg/ml nicotine shots

Total bottle volume	Target nicotine	Nicotine shot needed (18 mg/ml)	Shot count (10 ml bottles)	Base to top up (before flavour)
60 ml	3 mg/ml	10 ml	1 bottle	50 ml (then subtract flavour)
120 ml	3 mg/ml	20 ml	2 bottles	100 ml (then subtract flavour)
100 ml	3 mg/ml	16.7 ml	~1.7 bottles	83.3 ml (then subtract flavour)
50 ml	3 mg/ml	8.3 ml	~0.8 bottle	41.7 ml (then subtract flavour)

Note: flavour volume must also be subtracted from the remaining base to keep the final bottle volume exact.

VG / PG Ratio and PG Offset

Most flavour concentrates are carried in propylene glycol (PG). This PG must be included in the final VG/PG calculation.

Flavour concentrates contribute directly to PG
Only remaining PG should be added as pure PG

Ignoring PG offset results in thin liquid and increased leakage risk.

Step-by-Step Mixing Process

Define target volume and VG/PG ratio
Select flavour percentage
Calculate nicotine volume (if used)
Subtract flavour and nicotine from target volume
Add VG and PG to reach the exact final volume (include PG offset)
Cap the bottle and shake for 2–3 minutes

Steeping (Maturation Time)

DIY steeping guidance — typical maturation windows

Flavour family	Recommended time	What happens
Fruit profiles	1–3 days	Top notes smooth out, blend stabilises.
Mint / menthol	1–2 days	Cooling balance evens out.
Dessert / creamy	7–14 days	Body notes integrate, sweetness rounds.
Tobacco profiles	10–21+ days	Depth increases, harsh edges soften.

Store sealed and away from light; shake gently every 1–2 days for repeatability.

Common Beginner Mistakes

Using too much flavour concentrate
Ignoring PG contribution from flavours
Incorrect nicotine calculations
Insufficient mixing
Vaping immediately without proper steeping

Frequently Asked Questions (FAQ)

Can I vape DIY liquid immediately?

Yes, but flavour development usually improves after steeping. For fruit/menthol mixes this may be 1–3 days, while dessert and tobacco profiles commonly need longer maturation.

Why is my DIY liquid harsh?

Common causes include a high PG ratio, too much flavour concentrate, or nicotine-related harshness (including oxidation/ageing). Adjust the recipe conservatively and allow time for the mix to settle.

Do flavour concentrates count as PG?

Yes. Most concentrates are PG-based and must be included in PG calculations to avoid thinning and leaking.

Regulatory Context (Ireland / EU)

This page provides technical and educational information only. Sale of vaping products to persons under 18 years of age is prohibited by Irish law.

Nicotine notice: Nicotine is an addictive substance.

Intent disclosure: No medical advice, no smoking cessation claims.