Cold Beer: Buy Chilled, Warm Later?

It is a common misconception that cold beer will go bad if it is allowed to warm up to room temperature and then be cooled down again. This is a pervasive myth and, in most cases, nothing happens to the beer when it is subjected to temperature cycling. However, beer is best preserved when kept cold, as it will stay fresher for a longer period. Keeping beer at room temperature can reduce its shelf life from nearly six months to only a few weeks, and exposing it to very warm temperatures can affect its flavour in a matter of days.

Beer warming up and cooling again does not ruin it

It is a common misconception that warming up and cooling beer will ruin it. This is not true. Beer warming up and cooling again does not ruin it.

The idea that temperature cycling "skunks" beer is a pervasive myth. If this were true, all beer imported from Europe would be ruined before it was purchased. Beer shipped from overseas will have changed temperatures several times, yet non-skunked imported beer is easy to find.

It is true that temperature affects beer. However, it is not temperature cycling that ruins beer, but exposure to extreme temperature fluctuations and warm temperatures over an extended period. For example, leaving beer in a parked car in the sun may cause it to explode. Heat speeds up the process of oxidation, which can cause some beers to develop a stale, cardboard-like flavour, accompanied by a note of sherry. More malt-forward beers can even develop a sweet, bready, and toffee-like flavour. A beer's "hoppiness" will also dissipate with extreme heat.

To preserve the flavour of your beer, it is best to keep it cold.

Extreme temperature fluctuations can be harmful to beer

Extreme temperature fluctuations can indeed be harmful to beer. While a single instance of warming up and cooling cold beer does not affect its flavour, prolonged exposure to warm temperatures can. Beer is best preserved when kept cold.

Keeping beer at room temperature can reduce its shelf life from nearly six months to only a few weeks. Exposing the same beer to very warm temperatures can affect its flavour in a matter of a couple of days. Hop flavours and aromas will be diminished, and malt flavours that used to remind you of chocolate and caramel will begin to meld into a generic, sickly "sweet" flavour. In some beers, reminders of wet cardboard and paper can develop.

Temperature fluctuations can also cause the closure of the bottle to loosen, allowing oxygen to get in and make the beer go flat.

However, it is important to note that temperature cycling alone does not "skunk" beer. Skunking is caused by light interacting with a chemical compound found in hops.

Light is the number one cause of skunky beer

It is a common misconception that beer gets skunked because of temperature changes. In reality, light is the number one cause of skunky beer. Skunking is a chemical reaction that causes an awful, bitter taste. It is caused by light exposure, specifically, exposure to ultraviolet light or specific wavelengths of light. This light exposure interacts with the bitter hop compounds in a brew, creating a new compound that is nearly identical to one of the substances produced in a skunk's asshole. This is why skunky beer is called "lightstruck" by chemists and beer enthusiasts.

The speed of the reaction depends on the type of light and the amount of exposure. A glass of beer can become noticeably lightstruck in seconds when exposed to direct sunlight. On the other hand, brown glass beer bottles block nearly all of the offending wavelengths of light, and cans and kegs block out all light, preventing skunking. Green or clear glass bottles, on the other hand, do not block the specific wavelengths of light that cause the reaction, allowing the reaction to occur quickly.

The myth that temperature changes cause beer to become skunky is pervasive, with many people believing that letting cold beer warm up will ruin it. However, this is not true, and temperature changes have little to no effect on beer freshness. Beer that is imported from Europe, for example, would be ruined by the time it arrived if temperature changes caused skunking. While temperature does affect beer, it is exposure to warm temperatures over extended periods that can affect its flavour, not temperature cycling.

Beer is best preserved when kept cold

Temperature does, however, have an effect on beer. Exposure to warm temperatures will cause a beer's shelf life to decrease. For example, keeping beer at room temperature can reduce its shelf life from nearly six months to only a few weeks. Very warm temperatures can affect a beer's flavour in a matter of days.

Heat speeds up the process of oxidation, which can cause some beers to develop a stale, cardboard-like flavour, with a note of sherry. Beers that are more malt-forward can develop a sweet, bready, toffee-like flavour. The "hoppiness" of a beer will also dissipate in extreme heat, with any piney, citrusy, or floral hop aromas failing to linger.

It is important to note that it is not temperature cycling that destroys beer, but rather prolonged exposure to warm temperatures. Therefore, it is recommended to keep beer cold when possible to preserve its flavour.

Beer can be stored and displayed warm, but it is better to store it cold

However, temperature does affect beer. Exposure to warm temperatures will reduce a beer's shelf life. Keeping beer at room temperature can reduce its shelf life from nearly six months to only a few weeks. Very warm temperatures can affect its flavour in a matter of days. Heat speeds up the process of oxidation, which causes some beers to develop a stale, cardboard-like flavour, accompanied by a note of sherry. More malt-forward beers can even develop a sweet, bready, and toffee-like flavour. A beer's ""hoppiness" will also dissipate with extreme heat. The bitterness imparted by hops will remain in the mouthfeel, but any piney, citrusy, or floral hop aromas will not stick around for long in a too-hot beer.

Therefore, while it is not harmful to let cold beer warm up and cool down again, it is better to store beer cold. This will ensure that the beer stays fresh for longer and that its flavour is preserved as the brewer intended.

Frequently asked questions