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One drink carries the whole comparison: the Field Manual Gin and Tonic against a 250ml can.
The Field Manual Gin and Tonic takes 50ml of gin at 40% ABV and 100ml of chilled tonic water, built over ice in a copa or highball glass. The can in this comparison holds 250ml at 5% ABV. Those are sums chosen to be easy to follow, and they describe no product.
The can side comes from what a UK label states or leaves out, which how to read an RTD can sets out line by line. The glass side comes from the recipe. No price appears, because prices move, and no product is set against another.
Five differences decide it, and each can be checked against a label or a recipe.
The can is the lighter drink, in units and in concentration. The glass is the fresher drink, and the one whose sugar you can count from the recipe.
A 250ml canned gin and tonic at 5% ABV against the Field Manual Gin and Tonic, compared on strength, dilution, sugar, freshness and cost, from the label rules and the recipe
Strength
- Canned: 250ml at 5% ABV
- 5.0% ABV on the label. 12.5ml of pure alcohol, which is 1.25 UK units.
- Built in the glass: the Field Manual serve
- 50ml of gin at 40% ABV in 150ml of drink, about 13% ABV before the ice melts. 20ml of pure alcohol, which is 2.0 UK units.
Dilution
- Canned: 250ml at 5% ABV
- Fixed before the can is sealed. Ice poured over it adds more water.
- Built in the glass: the Field Manual serve
- Built over a glass full of ice, so the melt is part of the drink and slows while the glass stays cold.
Sugar
- Canned: 250ml at 5% ABV
- Not stated unless the producer prints it, because Article 16(4) lifts the nutrition declaration above 1.2% ABV.
- Built in the glass: the Field Manual serve
- 7.4g from 100ml of one full-sugar Indian tonic on Fever-Tree’s UK site; light versions sit near half of that.
Freshness
- Canned: 250ml at 5% ABV
- Filled and sealed at the factory, with a best before date below 10% ABV. The gas stays in until it is opened.
- Built in the glass: the Field Manual serve
- A lime wedge squeezed on the day, a tonic opened for the round, ice from the freezer.
Cost of the alcohol
- Canned: 250ml at 5% ABV
- About 33p of duty on 12.5ml of pure alcohol, at the 3.5% to 8.4% rate of £26.61 a litre.
- Built in the glass: the Field Manual serve
- About 68p of duty on 20ml of pure alcohol, at the rate above 22% ABV of £33.99 a litre.
| Question | Canned: 250ml at 5% ABV | Built in the glass: the Field Manual serve |
|---|---|---|
| Strength | 5.0% ABV on the label. 12.5ml of pure alcohol, which is 1.25 UK units. | 50ml of gin at 40% ABV in 150ml of drink, about 13% ABV before the ice melts. 20ml of pure alcohol, which is 2.0 UK units. |
| Dilution | Fixed before the can is sealed. Ice poured over it adds more water. | Built over a glass full of ice, so the melt is part of the drink and slows while the glass stays cold. |
| Sugar | Not stated unless the producer prints it, because Article 16(4) lifts the nutrition declaration above 1.2% ABV. | 7.4g from 100ml of one full-sugar Indian tonic on Fever-Tree’s UK site; light versions sit near half of that. |
| Freshness | Filled and sealed at the factory, with a best before date below 10% ABV. The gas stays in until it is opened. | A lime wedge squeezed on the day, a tonic opened for the round, ice from the freezer. |
| Cost of the alcohol | About 33p of duty on 12.5ml of pure alcohol, at the 3.5% to 8.4% rate of £26.61 a litre. | About 68p of duty on 20ml of pure alcohol, at the rate above 22% ABV of £33.99 a litre. |
The can holds less alcohol, and the label gives the figure to count it with.
The NHS sum turns a label into units: ABV, multiplied by millilitres, divided by 1,000. The can comes to 1.25 units. The glass, 50ml at 40% ABV, comes to 2.0. The can holds five eighths of the alcohol in the glass.
Concentration points the same way. In the can, alcohol is 5% of the liquid. In the glass, 20ml of pure alcohol sits in 150ml of liquid before any ice melts, which is about 13%. The same flavours sit in a weaker drink.
A larger or stronger can changes the answer. At 500ml and 7% ABV it comes to 3.5 units, well above the glass, while 330ml at 4% ABV comes to 1.3. The same sum prices the other drinks cans copy: the Paloma is 2.0 units, the Moscow Mule 1.8 and the Negroni 2.4, each from the ABV printed on its ingredient pages.
The printed strength carries a tolerance. Annex XII lets most drinks above 1.2% ABV differ from the figure by 0.3% vol in either direction, so a 250ml can printed at 5.0% vol. holds between 4.7% and 5.3%, a swing of about 0.15 of a unit.
Ice adds water to both drinks, and only the glass lets you choose how much.
Ice packed to the rim keeps a drink cold and melts slowly, which is why the highball glass page and the Gin and Tonic recipe both fill the glass. Ice scattered thinly in a tall glass gives way sooner, and the drink warms while it waters down.
A can arrives already at its label strength. Poured over ice, it takes the same melt as any other drink and loses strength by that amount. Poured into an empty glass, it takes none. How to serve a canned cocktail covers the pour.
A drink that goes into a can or a bottle skips the ice step, so the water it needs is in the liquid before it is sealed. Our batching guide shows the size of that water for a bottled drink: Difford’s Guide puts the dilution from shaking at roughly 25%, and from stirring at about 20%.
Gas is set at the factory in a can, and kept by the pour in a glass.
Food Republic, in April 2024, described how a canned cocktail is carbonated: carbon dioxide is forced into cold liquid with specialised equipment, and a sweet drink is harder to carbonate. A processing-equipment maker’s webinar page lists carbonating, pasteurising and filling among the production stages. Sealed, the can holds its gas until it is opened.
The gas in a homemade drink belongs to the tonic, which starts to lose it when the cap comes off. Our tonic water page puts the life of an opened bottle at a day or two, chilled. The pour matters as well: tonic sent down the inside wall of the glass keeps most of its gas, and tonic crashed into the middle loses much of it.
Both drinks lose some gas to the pour. Neither keeps all of it.
Sugar is printed on the recipe for the glass and optional on the can.
Under Article 16(4) of Regulation (EU) No 1169/2011, a drink above 1.2% ABV need not carry an ingredients list or a nutrition table. A can may therefore show no sugar figure, though a producer is free to print one and the Article does not oblige it to. A sugar figure is a question for the producer.
In the glass, you choose the sugar. On Fever-Tree’s UK site, one full-sugar Indian tonic is listed at 7.4g of sugar per 100ml, so the 100ml in a Field Manual Gin and Tonic carries about 7.4g if that is the tonic used. A light tonic changes the figure and the drink. The Paloma needs no syrup, because its grapefruit soda brings the sugar, the fizz and the grapefruit in one pour, so its sugar is whatever the bottle carries.
Sugar also decides how a drink balances against its dilution and acid, which understanding cocktail balance takes in turn.
Fresh citrus is the clearest gap, and it is measured in hours.
Our lime juice page puts juiced lime at the same day, and three hours at most for a Daiquiri. The wedge squeezed over a Gin and Tonic is the freshest thing in the glass, because it is a minute old.
A sealed can carries a date instead. Annex X gives the best before wording for drinks below 10% ABV, and the date is the producer’s estimate of how long quality holds, which is longer than a squeezed lime keeps. Because Article 16(4) lifts the ingredients list, whether a given can holds fresh, pasteurised or no citrus is a question for the producer.
Other drinks fade faster still. The foam on an Espresso Martini comes from the crema of an espresso pulled just before shaking, and our page warns that crema begins to collapse in minutes. A drink that depends on something that fades that fast belongs in the glass.
Cost is a sum done with your own receipts, and duty is the one fixed part.
GOV.UK’s table for spirit-based products, updated on 1 February 2026, sets £26.61 a litre of pure alcohol between 3.5% and 8.4% ABV and £33.99 a litre above 22% ABV. The can holds 12.5ml of pure alcohol, which at that rate is about 33p of duty. The 50ml of gin holds 20ml, which is about 68p.
Per unit of alcohol, which is 10ml, the can carries about 27p of duty and the gin about 34p, because the rate rises with strength. Both figures come before VAT, and neither is a shelf price.
The rest of the can’s cost is the work between the spirit and the shelf: the stages GEA’s webinar page names, then packaging, VAT and delivery. The rest of the glass’s cost is a bottle of gin divided by its 14 serves of 50ml, plus 100ml of tonic, a lime wedge and ice. An opened bottle of tonic goes flat within a day or two, so a single drink costs a share of a bottle.
To compare them, divide each price by its units: the can by 1.25, the glass by 2.0. The lower figure is the cheaper unit of alcohol, and the receipts are yours to read.
The can wins where glassware, ice and a bar do not travel.
The picnic section of our summer cocktails guide carries the parts and not the mix, because a mix carried in a bag warms and loses its gas on the way. A sealed can is a different case. Keep it cold in a cool bag beside a water bottle frozen overnight. It also avoids glass, and local restrictions on alcohol or glass in parks and on beaches are worth checking before you pack.
A can is one serve, which suits a guest who wants one drink. The glass wins when you want to set the strength, use fresh citrus, choose the tonic or pour several rounds from one bottle. You cannot make a can weaker or stronger. You can only pour it.
A bottle you fill yourself sits between the two.
The home version of the shop-bought bottle is in the bottling section of how to batch cocktails. It bottles a stirred, citrus-free drink such as a Negroni, adds the water first, freezes it for three hours or more and serves it into a chilled glass. Write the drink and the date on the bottle.
The shop-bought equivalent is the bottled stirred cocktail in what a ready-to-drink cocktail is, read with the label rules in how to read an RTD can.