# 100ml e-liquid with nicotine: what the bottle holds > 100ml e-liquid with nicotine: why the bottle is sold at 0 mg, what adding nicotine shots changes, and how to keep it over several weeks. Looking for a 100ml e-liquid with nicotine on a British shelf means looking for a product that does not exist in that shape. Search engines return hundreds of pages regardless, which keeps the confusion alive. Behind the query sits a fairly simple fact of composition, but one that changes a great deal about what the bottle contains, how its flavour is balanced, and how it ages once opened. ## 100ml e-liquid with nicotine: why the bottle is sold at 0 mg The rules in force in the United Kingdom cap nicotine-containing e-liquid at 10 ml per container and at 20 mg of nicotine per millilitre. A sealed 100 ml bottle carrying nicotine would breach the first limit outright, whatever its strength. The trade's answer is the shortfill. The flavoured liquid is sold at 0 mg, where no volume cap applies, and the nicotine arrives separately in compliant 10 ml shots that the buyer adds at home. So the honest description of a 100ml e-liquid with nicotine is a two-part product: a large bottle of nicotine-free liquid, plus the small bottles that turn it into a finished mix. ## What a 100 ml bottle actually contains The physical bottle is not 100 ml. British 100 ml shortfills are almost universally supplied in a 120 ml bottle holding 100 ml of liquid, with 20 ml of deliberate headroom above it. That headroom is not slack packing. It is measured to take exactly two 10 ml nicotine shots, which is why retailers so often bundle a pair with the bottle. Fifty millilitre shortfills follow the same logic on a smaller scale, arriving as 50 ml of liquid in a 60 ml bottle with room for a single shot. The pattern is consistent across the market and it is the quickest way to identify a shortfill on sight. ## The base is deliberately over-flavoured A liquid designed to be diluted by a sixth of its volume cannot be balanced as though it were finished. Shortfill bases are therefore concentrated above the level of a ready-to-vape 10 ml product. Vaped straight from the bottle at 0 mg, many of them taste heavy or slightly harsh, and that is not a fault. It is the formulation doing exactly what it was built to do, waiting for the dilution it expects. This also explains why adding fewer shots than the bottle was designed around leaves the flavour sitting oddly strong, while adding more than it can hold pushes it thin. ## What adding nicotine displaces in the bottle Two 10 ml shots poured into 100 ml of base do three things at once, and only one of them concerns nicotine. They add the nicotine, obviously. They also dilute every aromatic compound by roughly a sixth. And they shift the finished PG/VG ratio towards whatever ratio the shots themselves were made in. British shots come in 50/50 and 70/30 VG, and the mismatch matters. Two 50/50 shots dropped into a 70/30 base pull the finished liquid down by a couple of points of VG, which is small but real on a high VG mix. The nicotine arithmetic is straightforward. Two 18 mg/ml shots carry 360 mg into 120 ml of finished liquid, giving 3 mg/ml; two 20 mg/ml salt shots carry 400 mg into the same volume, giving 3.3 mg/ml. Neither figure is a recommendation, only the result of a division. ## Keeping a nicotinated 100 ml over several weeks A bottle this size is not consumed in a weekend, so how it is stored between uses genuinely affects what is left at the bottom. The main variable is residual air. As the liquid goes down, the volume of air above it grows, and oxygen is what turns nicotine over time. A bottle two thirds empty ages measurably faster than a full one. Decanting into smaller bottles is the standard answer among people who buy this format, and it works for a plain physical reason: less headroom means less oxygen in contact with the liquid. ## Light, heat and the material of the bottle Sunlight and warmth accelerate the same reaction. A bottle left on a windowsill or in a car in summer will darken faster than an identical one in a drawer. The colour change is the visible marker. A nicotinated liquid drifting from pale straw to amber has oxidised, which alters the flavour and pulls the delivered strength slightly below what the label arithmetic promised. Most British shortfills come in PET, which is convenient and lightweight but more permeable to oxygen over long periods than glass. For a bottle intended to last months rather than weeks, glass and a cool dark cupboard are the more stable pairing. ## Recognising a large bottle built for shots Three signs identify it before purchase and none require reading the small print carefully. The stated volume sits below the bottle size, so 100 ml in a 120 ml bottle. The strength is printed as 0 mg. And the product page mentions nicotine shots, usually with a note on how many the headroom takes. If a bottle carries a nicotine strength above zero and a volume above 10 ml, something is wrong. On the British market that combination should not exist, and it is a reason to buy elsewhere. ## Maturation after the shots go in The mix needs a shake, and it may need a wait. The shake is not optional: salt-form and freebase shots are both denser than the flavoured base and will otherwise sit in a layer. The waiting period, which mixers call steeping, is about flavour rather than nicotine. Fruit-led bases often need nothing at all, while heavier custard and tobacco profiles are commonly given several days to settle after dilution. There is no chemistry that requires it for the nicotine itself. Once shaken, the nicotine is evenly distributed and the calculated strength holds from the first millilitre. ## 100ml e-liquid with nicotine: the points that matter Three things decide what you end up with, and none of them is the brand on the label. The headroom, which sets how many shots the bottle can physically take. The shot ratio, which nudges the finished PG/VG. And the storage, which determines whether the liquid at the bottom of the bottle in six weeks resembles the liquid at the top today. Writing the calculated strength and the mixing date on the label is the only reliable record of what is inside. ## Frequently asked questions ### Does a shortfill keep less well once nicotine is added? Yes, somewhat. Nicotine oxidises where the 0 mg base has far less to react with, so a mixed bottle has a shorter useful life than an unopened one. ### Is liquid that has darkened unusable? Not unusable, but changed. Darkening indicates oxidation, which shifts the flavour and takes the delivered strength slightly below the calculated figure. ### Can I nicotinate only part of the bottle? Yes, by decanting a measured volume and mixing that separately. A graduated syringe is needed, because the calculation depends entirely on knowing both volumes exactly. ### Should nicotine shots be kept in the fridge? Cool and dark is enough for normal timescales. Refrigeration slows oxidation further but risks condensation inside the bottle each time it is opened. ### How long does an unopened large bottle last? Manufacturers generally state one to two years for a sealed 0 mg base kept cool and dark. The printed date on the bottle is the figure to trust. ## The short version on a nicotinated large bottle A 100ml e-liquid with nicotine is not one product but two, joined at home: a deliberately over-flavoured 0 mg base in an oversized bottle, and the 10 ml shots that the legal ceiling of 20 mg/ml forces into that separate format. Everything that follows, the flavour dilution, the ratio shift and the faster ageing, is a consequence of that split rather than a defect. Store it cool, dark and as full as you can, and write the calculated strength on the label. For the arithmetic behind the shot count, our [nic salt shot chart](/uk/nic-salt-shot-chart/) lays out the numbers by volume, the [nic salt shot](/uk/nic-salt-shot/) piece covers what the small bottle contains, and [pg vg](/uk/pg-vg-explained/) explains the ratio the dilution moves. Independent editorial content for adults only. Vaping products contain nicotine, which is a highly addictive substance. Not for sale to under-18s in the United Kingdom. This article is not a buying recommendation.