Base liquid: how to choose it without a mistake

Stand in front of a shelf of mixing supplies and everything looks the same: clear bottles, numbers that change, sizes from 100 ml to a full litre. Nothing tells you which one suits your hardware, or why the cost per millilitre swings so widely. Choosing a base liquid actually comes down to two pieces of information, and the second one is printed on the label.

The quick answer: 50/50 for a pod, more VG for sub ohm

A base liquid is chosen first and foremost according to the coil you use. Above 1 ohm, on a tight mouth to lung draw, a 50/50 works in almost every case.

Below 1 ohm, on a higher power build, aim for 30 PG / 70 VG or 20 PG / 80 VG. The extra viscosity feeds the wide wicking ports of those coils properly without flooding them.

The bottle size comes second. A 100 ml bottle is enough to try the idea out, while 500 ml or a litre make sense once mixing becomes a habit. The cost per millilitre drops noticeably past the half litre mark.

What a base liquid contains

The word base describes a deliberately poor product. Its neutrality is exactly what makes it the raw material for everything else, and two ingredients are enough to define it.

A base is a blend of propylene glycol and vegetable glycerine, with no flavouring and no nicotine. It makes up the bulk of the final volume of a home mix, generally somewhere between 70 and 95 percent depending on how much concentrate the recipe calls for.

Propylene glycol thins the mix and carries flavour. Vegetable glycerine thickens it and produces volume. The ratio printed on the bottle gives the proportion of each, in the order the letters are printed, which is worth checking against our note on the 70/30 ratio and its labelling.

Grade and purity, the one criterion that separates two bottles

Serious suppliers state a pharmaceutical grade, written USP or Ph. Eur. depending on the pharmacopoeia they refer to. British listings often add EP grade for the glycerine, which amounts to the same idea.

That statement appears on the label or on the manufacturer’s technical sheet, and it is the only composition criterion that genuinely distinguishes two bottles of the same ratio. Everything else comes down to packaging and volume.

Some sellers also publish a certificate of analysis for a given batch. It is not something a casual mixer needs to read in detail, but its presence says something about how the supplier operates.

Base mix, diluent, neutral base: the same product

The confusion comes from shop vocabulary rather than from the product itself. Several names circulate on British shelves and they all describe one thing.

A base mix, a VG/PG diluent, a neutral base and a DIY base are a single unflavoured propylene glycol and glycerine blend. Retailers pick whichever term suits their own category tree.

One nuance is worth adding. Older pages still mention a nicotine containing base in large volumes, and that format has gone.

Under the Tobacco and Related Products Regulations 2016, nicotine containing liquid is capped at 20 mg/ml and sold in bottles of no more than 10 ml, with tanks limited to 2 ml. That cap is precisely what created the shortfill and the separately sold nicotine salt shot.

Choosing your base liquid ratio according to the hardware

The ratio is not a matter of taste but a mechanical constraint. A liquid that does not reach the cotton fast enough will eventually scorch it, however good the ingredients are.

An 80/20 or a 70/30 with propylene glycol in the majority targets small atomisers and narrow coils. Flavour comes through with precision and fouling stays slow, which suits tobacco and menthol profiles where definition matters more than volume.

The 50/50 works on very nearly every pod and tank on the British market. It is the one to pick when in doubt, or when several different devices live in the same house.

The 30/70 and the 20/80 belong to rebuildables and sub ohm coils. The glycerine produces a dense volume there, at the price of consumables that clog appreciably faster.

A litre of pure vegetable glycerine also exists, but its viscosity punishes coils quickly and mutes flavour. It mostly serves to adjust a blend rather than to be used on its own.

What a base liquid changes in the cost per millilitre

This is the most concrete argument for mixing at home, and it deserves to be worked out rather than assumed. Three lines are enough for an honest comparison.

Add together the cost of the base pro rata to the volume used, the cost of the flavour concentrate at the percentage chosen, and the cost of the nicotine shot if you add one. Divide the total by the final volume you obtain.

The calculation has to include two expenses people routinely forget: empty graduated bottles, and the occasional failed recipe you never finish. One flop in ten wipes out a meaningful slice of the difference.

A last parameter weighs in, and it is time rather than money. A simple fruit mix wants two or three days to settle, a complex dessert two or three weeks. Building that delay into the plan is what stops a batch being judged too early and thrown away.

Storing your bases without spoiling them

A base is stable, not indestructible. Storage conditions explain most of the bottles that turn yellowish at the back of a cupboard.

Keep bottles upright, properly closed, out of direct light and away from any heat source. Vegetable glycerine draws moisture from the air, which slightly alters the viscosity of a bottle that gets opened often.

Write the date it was first opened on the cap in marker pen. On an opened litre, that is the one piece of information always missing when you come back to it.

One habit is worth adopting: decant into a 100 ml bottle the amount you expect to use over the month. The litre stays sealed, it ages less, and daily handling becomes safer than wrestling with a heavy container.

Two bases of different ratios can also live together without any problem. Plenty of mixers keep a litre of 50/50 and a litre of pure glycerine, which lets them compose any intermediate proportion at mixing time without stocking more references.

Handle the mixing itself with the same care you would give any concentrated ingredient: gloves on, well away from children and pets, on a surface that wipes clean. That advice belongs on a base bottle as much as on a nicotine shot, and it is spelled out further in our guide to the DIY e-liquid kit.

Frequently asked questions

Can you vape a base liquid with no flavouring?

Technically yes, the blend is designed to be heated. The result is neutral, faintly sweet from the glycerine, and of no particular interest to taste.

Do I need a graduated bottle to mix?

It is strongly recommended beyond two ingredients. The markings printed on a 60 ml bottle give enough precision for everyday use without going as far as scales.

What is the difference between a base and a large bottle of e-liquid?

The large bottle, sold here as a shortfill, is already flavoured and ready to vape apart from any nicotine you add. A base carries no flavouring at all and serves as the starting point for a recipe.

Can a base contain water or alcohol?

Some formulations include a small share of either to thin the blend. The full composition appears on the product sheet, which is the only way to know.

How long does an unopened base keep?

Manufacturers generally state several years for a sealed bottle stored correctly. The printed best before date is the reference to go by.

Base liquid: the two figures that decide everything

The ratio governs compatibility with your hardware, the format governs the cost per millilitre. Everything else, brand, cap design, label colour, comes a long way behind.

Choosing a base liquid therefore comes down to answering one simple question: which coil am I going to use, and over what volume. Once those two points are fixed, an intimidating shelf shrinks to three or four genuinely relevant references.

Editorial content for adult readers only. Vaping products usually contain nicotine, a substance that causes addiction. Not for sale to under-18s in the United Kingdom. This article is not a buying recommendation.