Cans and bottles do not change what a beer is, but they change what a beer does while it waits for you, and the two packages behave differently in three specific ways. A can is opaque, so nothing gets in through light. A can has a thinner barrier between the beer and the air, so what gets in through the closure is a different kind of risk than what gets through glass. And a can is cold and light while a bottle is heavy and thermal, so they arrive in your hand differently. Those three things, light, oxygen and temperature, are the whole argument, and once you can hold them separately you can pick the right package for the beer rather than the beer for the package. Our separate look at the can on its own explains why breweries moved to it, and this page is the head-to-head, because a lot of the confusion on this subject comes from a can discussion and a bottle discussion being treated as the same argument.
Choosing Between A Can And A Bottle
- Choose the can for a hop-forward beer you will drink within weeks.
- Choose the bottle for an aged or bottle-conditioned beer with a long aromatic nose.
- Buy the can to drink now and save the bottle for later.
- Keep both packages cold, because neither one rescues a beer left in a hot car.
Light: The One Thing A Can Wins Completely
The clearest difference between the two packages is light, and it is not a subtle one. Ultraviolet light acts on the hop compounds already dissolved in the beer and converts them into a skunky, sunlit, wet-cardboard note, and that reaction is fast, irreversible and entirely the package's fault, because the beer did nothing wrong and the light did everything to it. A brown or amber glass bottle exists for precisely this reason, since the coloured glass filters out most of the wavelengths that cause it, which is why a session bitter or an export pale ale was always sold in brown glass. A can is opaque aluminium and blocks essentially all of it. So a can of a hop-heavy beer will taste fresher and cleaner than a clear or green bottle of the exact same beer that has sat under fridge lights or a shop window, because the bottle version has been quietly lightstruck and the can version has not. Our piece on the chemistry of hops explains why the reaction smells so bad, and for a hoppy beer this single difference is usually the biggest reason a can tastes better, because hop aroma is the first thing light destroys.
Oxygen: The One Thing A Bottle Wins On
Here the advantage reverses, and this is the part a can-versus-bottle conversation often gets wrong. Once beer is packaged it is a sealed chemistry problem, because beer is brewed without oxygen and the moment air gets in, the ethanol in it starts to oxidize into acetaldehyde, which smells like green apple and cut apple and is the compound drinkers most often describe as cardboard or nail-polish remover. The question for packaging is how much air, if any, can get in. Glass is an excellent barrier to gas in its own right, and a bottle with a good crown cap and a cork liner is a genuinely near-hermetic seal. A can relies more heavily on the closure, a rolled seam and a plastic liner, and the failure mode of each is different, since a can is more dependent on the top being seated correctly while a bottle depends on the cap biting the lip. Neither is a reason to distrust cans, because a correctly filled can is well protected, and the real risk on both is the same thing, which is a warm, damaged, or long-stored package rather than the material itself. The honest summary is that light is where a can decisively wins and oxygen is a closer contest than the marketing suggests, and neither package saves a beer that has been left in a hot car.
Heat: The Difference You Feel In Your Hand
The third difference is physical rather than chemical, and you notice it before you taste it. Glass is dense and conducts heat well, so a bottle that has been sitting at room temperature takes a long time to chill and then holds its cold for a long time. Aluminium is light and thin and pulls heat out of the liquid far faster, so a can drops to fridge temperature in a fraction of the time and, being lighter in the hand, feels colder for less effort. Most craft beer is drunk well below cellar temperature, where the delicate hop and ester character is showing rather than hidden by warmth, and that is exactly the temperature at which a can is at its best. So a can gives you cold beer fast, a bottle gives you cold beer that stays cold, and which one you want depends on whether you are drinking it now on a walk or saving it for an evening at a table. This is a real difference in how the two behave, and it is about heat rather than chemistry, but it changes the drink as much as any of the other two.
The Head To Head
| Can | Bottle | |
|---|---|---|
| Light | Blocks it entirely | Depends on glass colour; brown and amber filter it, clear and green do not |
| Oxygen | Good seal, but depends more on the closure | Excellent glass barrier, good crown cap or cork seal |
| Chilling | Cools very fast, light in the hand | Slow to chill, holds cold well, heavy in the hand |
| Aroma in the glass | Bottles are often judged by aroma, so a taster still prefers one | Aroma is easier to judge from a bottle |
| Durability in transit | Dents but does not shatter | Shatters if knocked or dropped |
| Best for | Hoppy beers bought to drink fresh, single serves, cold beer fast | Beers with age in them, aromatic sips, keeping cold for longer |
The aroma row is worth pausing on, because it explains why the two formats have both survived. Aroma is one of the things a can genuinely cannot match in a bottle, since part of judging a beer by its smell involves getting your nose close to the opening and swirling it, and a narrow can lid does not let you do that the way the wide mouth of a bottle does. For a beer whose whole point is a complex, aromatic nose, an expert taster will often still reach for the bottle, and for a casual drinker a can loses nothing, because you are tasting the beer rather than analyzing it. That is the real reason the best breweries now put the same beer in both, so the bottle drinkers and the lightstruck-averse drinkers can each have what suits them, and neither format has won.
Choosing For The Beer In Front Of You
A working rule is straightforward. If the beer is hop-forward, fresh, and something you will drink within weeks, the can is the safer buy, because it blocks light and it is what the brewery is usually leading with. If the beer is a bottle-conditioned or aged style, something with a long aromatic nose, or a beer you want to open at a table and smell before you drink, the bottle is the better choice, because it holds cold longer and it lets you judge the aroma properly. And if you have both, buy the can to drink now and save the bottle, because that pairing gets you the freshest version at its most drinkable and a bottle that still has something to give later. The packaging never made the beer better or worse, it just decided how long the light and the air got at it, and choosing well is really choosing which faults you would rather avoid for the beer in your hand.
Frequently Asked Questions
Does a can make beer taste metallic?
No, not from the can itself, and the concern is largely a leftover from the early days of canned lager when the inside of the can was not prepared as well and the beer really did pick up a tinny note. Modern cans are lined with a food-grade coating so the beer never touches bare metal, and a metallic taste in a canned beer almost always comes from somewhere else, most often oxidation from warm or long storage, or from a beer that is simply old. If a can tastes metallic and the bottle of the same beer does not, the most likely explanation is that the can has been somewhere warm for a while and the oxidation has set in, which is a storage fault rather than a packaging fault. A cold can drunk fresh should not taste of metal at all.
Is bottled beer better for the environment?
It is not a simple answer, and the honest version is that neither package is straightforwardly greener than the other. A can is far lighter than a glass bottle of the same volume, so it costs much less to ship, and shipping is a large part of a beer's footprint, which counts in the can's favour. Glass is infinitely recyclable and a bottle that is reused rather than single-use offsets a lot, and aluminium is also highly recyclable, though the energy and cost of remelting metal is higher than remelting glass. The strongest single factor is not the material but the local recycling system and whether you actually recycle it, and in British Columbia both glass and aluminium are accepted in most municipal programs, so the choice between them is a small part of the picture next to getting the package back into the bin. If you want to do better, recycle the package and buy the format you will finish, since a half-drunk bottle is worse for the footprint than either material.
Why does a bottled beer from the fridge taste different from a canned one?
Usually the cold, and sometimes the light. A can and a bottle taken from the same fridge are both cold, so if the canned one tastes fresher or cleaner the likely reason is that the bottled one has been exposed to more light, either through a clear or green bottle or through a fridge door with the light on, and the hop character has faded into that skunky note. If the bottled one tastes warmer or flatter, the difference is just the glass holding temperature differently, and letting the bottle sit out for a few minutes before you open it fixes that. The remaining possibility is that they are not actually the same lot, since some breweries do put slightly different beer in a can and a bottle, but for most breweries the two formats hold the same liquid, so a difference you can taste is almost always light or heat rather than recipe.
Pick The Package For When You Will Drink It
The shortest useful summary of all of this is that a can is the fresh, cold, lightproof, single-serve choice and a bottle is the cold, aromatic, longer-keeping one, and the reason both are on the shelf at once is that they suit different moments. If you are working through a hoppy pale ale bought this week, reach for the can, because the light and the speed to cold are both working for you. If you have an aromatic, aged, or bottle-conditioned beer, or you are sitting down to smell and savour it, reach for the bottle, because the aroma and the cold retention are working for you. Neither package is a shortcut or a compromise, they are two different answers to the same problem of getting beer from a tank to your glass with as little damage as the packaging allows, and the flavour difference you notice between them is almost always light and temperature rather than anything the brewer did differently.
