DIY base: choosing your PG/VG ratio and mixing rate

Most mixers pick their concentrate first and then reach for whichever DIY base happens to be on the shelf. It should be the other way round. The base accounts for eighty to ninety per cent of the finished volume, which means it decides the flavour rate that makes sense, the length of the steep and what actually reaches your mouth. The concentrate only arrives afterwards.

What a DIY base is and what it decides

A DIY base is a mixture of propylene glycol and vegetable glycerine, sometimes with a little distilled water, sold with no flavouring and no nicotine. British suppliers usually call it a VG/PG base mix, and it is the support the whole recipe sits on.

Its ratio governs three things at once. Propylene glycol carries flavour and produces the sensation at the back of the throat. Vegetable glycerine thickens, softens and increases vapour, but it masks part of the finer notes and holds aroma molecules for longer.

The direct consequence is worth stating plainly. With the same concentrate, a base richer in glycerine needs more flavour and a longer rest. That is not a matter of taste, it is a property of the support you chose.

The common ratios and who they suit

Four ratios structure what is on sale in Britain. The choice is made first on the hardware you run, and only then on the result you are chasing.

A 70 PG and 30 VG mix suits high resistance coils and tight draws. It is fluid, it holds detail well and it marks the throat. A 50/50 remains the versatile compromise and works in the great majority of pod systems and mouth to lung tanks sold here.

The 30/70 and max VG mixes belong with low resistance builds and airy draws. They produce more vapour, ask for more power and behave noticeably more sluggishly in the wick, which matters if your device was not designed for them.

How the ratio moves your flavour rate

Concentrate houses formalise this relationship in their own guidance, and the slope is remarkably consistent from one brand to the next even when the exact figures are not. A base heavy in propylene glycol takes the lower end of a published range, a glycerine heavy one takes the upper end.

Vampire Vape puts the practical case in numbers on its concentrates page: a 30 ml bottle makes between 200 and 250 ml of finished liquid at a mixing ratio of fifteen to twenty per cent, and it advises starting lower, around five to fifteen, and testing from there. Several British stockists mirror the same advice from the other direction, suggesting the lower half of a published band for high PG mixes.

Those figures belong to specific bottles and are not transferable as they stand. Take the grid published by the house that made your concentrate, apply the ratio correction, and treat everything else as context rather than instruction.

Adding nic shots to a DIY base without losing volume

A DIY base is sold with no nicotine in it. To add any, British mixing uses nic shots, small bottles of heavily nicotined base that go into the mix. The method is simple, and the volume error is extremely common.

The regulatory ceilings frame the arithmetic. Nicotine containing e-liquid is capped at 20 mg per ml and refill bottles at 10 ml, so one shot carries at most 200 mg of nicotine. Divide the total nicotine you have added by the total finished volume and you have the strength of the mix, whatever that figure comes out as.

Take a shortfill as the model, since it is how most people meet the system. Fifty millilitres of unnicotined liquid sit in a 60 ml bottle, one 10 ml shot fills the gap, and the finished 60 ml carries the shot’s 200 mg spread across the whole bottle. Do the same sum on a bottle you built yourself and nothing changes except that you chose the base.

The part that trips people up is that a shot has its own ratio, commonly full VG or 50/50. Adding a sixth of your finished volume in shot therefore moves the final ratio of the mix by several points. A liquid planned as a 50/50 can finish at 45/55 without anyone noticing, and the flavour rate you calculated no longer matches the base you are actually vaping.

Bottles, pouring order and safety

The order you pour in decides how easy a correction will be. Concentrate first, shots second, base last to top up to the line. That is the only sequence that leaves you room to fix an overdose, because you can always add base and never remove it.

Handle nicotine with gloves, wipe the bench down afterwards, and keep every bottle, shot and concentrate out of reach of children and animals. Store the lot dry, away from direct light and away from heat, which slows the drift of the mix as much as it protects the nicotine.

Choose the bottle for the storage you intend. PET is fine for a working bottle emptied over a few weeks, amber glass is the sensible option for anything kept for months. Both need a label carrying the rate, the ratio and the date.

What the ratio does to your steep

Rest follows the logic of the support. A mix at 70/30 homogenises in a few days, while the same recipe at 30/70 often wants one to two weeks longer, because glycerine slows the diffusion of the aroma molecules through the liquid.

That difference has a practical consequence for how you organise a mixing session. If you fill several bottles on the same day at different ratios, they will not be ready at the same time, and comparing them all after one week tells you nothing useful.

The habit worth building is writing two dates on the label rather than one: the day you mixed it and the day you plan to taste it first. On a glycerine heavy base that gap comfortably exceeds ten days, and a dry dessert such as a hazelnut flavour concentrate can stretch it further still.

The costliest mixing mistakes

None of these show up while you are pouring. They only appear at the first tasting, and by then the bottle is full and the options are limited.

Calculating the flavour rate on the base volume instead of the finished volume is the most frequent, and it always gives a weaker mix than intended. Filling the bottle to the brim before adding the shots is the second, and it leaves nowhere for them to go. Using one syringe for base and concentrate without rinsing it contaminates everything that follows. Taking one brand’s published grid and applying it to another brand’s concentrate is the fourth, and it is the hardest to spot because the number looks plausible.

Frequently asked questions

Does a DIY base go off?

It carries a durability date, generally two to three years, and keeps well sealed and out of the light. A base that has yellowed or thickened abnormally is worth replacing rather than using as a support.

Can I blend two bases of different ratios?

Yes, and it is the simplest way to reach an intermediate ratio. Mixing equal parts of a 70/30 and a 30/70 gives you a 50/50 without buying a third bottle.

Should I add distilled water to a max VG base?

Some mixers add three to five per cent to thin a very thick liquid and help it feed the wick. It also dilutes the flavour slightly, so adjust the rate rather than the water if the result comes out flat.

Can a plain base be vaped on its own?

Technically yes, with nothing to recommend it. Without flavouring there is only the throat sensation and the vapour, which is occasionally useful for testing a new build and nothing else.

Why does my liquid crackle in the coil?

A ratio too rich in propylene glycol on a build designed for glycerine, or a power setting badly matched to the coil, both produce that behaviour. Check the compatibility between the ratio and the coil value before blaming the recipe.

Pick the DIY base before you pick the flavour

A DIY base is not an interchangeable consumable. It is the variable that fixes your flavour rate, your steep time and the way the liquid behaves in your hardware, so choosing the ratio first simplifies everything that comes after it.

Once that decision is made, published grids become readable and reproducible, including on demanding profiles where the maker and the retailers disagree, as they do on the Red Astaire concentrate. It is also what lets you judge a ready assembled DIY kit on something better than its packaging, because you will know what its base was doing to its flavour rate all along.

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.