Many people have experienced letting beer get overly warm, whether at a pool party or in the trunk of a car on a summer day. The big question: is beer spoiled if it gets hot?
While heat will shorten the life of a beer, it does not make it go bad, spoil it, or skunk it in the short term. Extended exposure to elevated temperatures will accelerate aging and oxidation, contribute to off-flavors, and reduce the beer’s drinkability.
Continue reading for more information about how heat can affect beer, what causes skunking, and whether chilled beer that is brought to a higher temperature and then cooled down again is alright to drink.
Does beer go bad if it gets hot?
All beer has a shelf-life. In most cases, the sooner it can be consumed at a proper temperature, the better for the drinker’s enjoyment. Exposure to heat on occasion — say, a long, unrefrigerated car ride on a warm day — will not ruin the beer, but it can shorten the window of time in which it will taste fresh.
Introducing heat for an extended period of time will cause the beer to oxidize more rapidly (more on that in a moment) and lead to off-flavors. Refrigeration keeps this process at bay for a longer period of time than storing at room temperature or warmer.
How does heat affect beer?
Bottles, cans, and kegs of beer all contain at least a little oxygen. Given time, the chemical reaction of the beer and oxygen together will result in oxidation. Oxidation causes a stale, cardboard-like taste to the beer.
Refrigeration slows down that oxidation process. In addition, refrigerators don’t just supply cold; they are also usually dark (or, at the very least, they protect their contents from sunlight). Storing beer in a cool, dark space not only slows oxidation but prevents lightstrike, or exposure to too much natural light.
Light-struck beer can taste skunked — musty, pungent — as a result. Dark brown bottles provide some amount of a barrier to UV rays, but even they can fall victim to extended light exposure. Lighter-colored and clear bottles are especially at risk of becoming skunked if they are not kept away from natural light.
While no beer benefits from being skunked, some beer can produce mellower, richer, more complex aromas if allowed age. Oxidation will occur during this aging process, but if aged gently, this oxidation can supply spicy and dried fruit qualities. On the other hand, Hot maturation can produce notes of toasted nuts, caramel, or orange zest, similar to maderization in wine.
At what temperature does beer go bad?
There is not one specific temperature threshold at which beer will instantly taste stale. Instead, that is determined by a combination of temperature and time.
Beer stored outside of a refrigerator, whether room temperature or warmer, has an accelerated ticking clock on its freshness. According to Craft Beer USA, “A general rule of thumb for the brewing industry is that beer stored at 100°F for one week tastes as old as beer stored at 70°F for two months, or as old as beer stored at 40°F for one year.”
Every beer has an estimated ‘best by’ date, a time frame for the brewery to guess that their beer will still taste fresh if the consumer keeps it cold. Given enough time, even refrigerated beer will become stale.
Does beer go bad if not refrigerated?
As mentioned above, refrigeration will dramatically slow the natural oxidation process of beer. Storing beer at room temperature away from natural light will also curb oxidation, just not as effectively.
Even exposure to moderate heat, like keeping a case of beer in a garage, will not be the deciding factor on whether the beer is ruined or not. Rather, the beer will produce those off-flavors of oxidation much more quickly than if the beer had been stored in a cooler space for the same amount of time.
If you’re unsure whether a bottle is ruined, give it a taste before dumping it out. Beer can become spoiled for a variety of reasons, but thankfully spoiled beer is very unlikely to make you sick due to its alcohol content and acidic nature.
What happens if beer goes from cold to hot to cold again?
In the same way refrigeration can preserve food, lower temperatures extend the freshness of beer. Unlike food, however, beer can sustain fluctuations in temperature without spoiling.
Most likely, beer was bottled or canned at room temperature at the brewery, placed in either a refrigerated or non-refrigerated truck or shipping container, and then refrigerated or stored at room temperature at the store before a consumer could even purchase it. It may have even spent a few hours on a pallet outside as the truck was getting loaded up.
That’s all to say that beer isn’t too delicate to handle the transition from a refrigerator to room temperature and back again, even a couple of times.
Of course, you’ll want to use some judgment here. There’s a big difference between a refrigerator and a basement floor, sure. Still, there’s an even more noticeable difference between beer being in a refrigerator and then being moved to an hours-long backyard party on a 95-degree day before going back into the refrigerator. In that situation, the beer would have been exposed to both light and heat for too long and will, most likely, be ruined.
What if homebrew beer gets too hot?
From the brewing process through storage of the final product, homebrewers need to be mindful of temperature control each step of the way.
- Wort temperature: Check the packaging the yeast came in for an ideal temperature range to pitch the yeast. If the wort is too hot, the yeast will die.
- Ambient temperature during fermentation: yeast is happiest in a consistent environment as it converts sugar into alcohol. If kept in an environment that is too hot, it can produce off-flavors or kill the yeast.
- Bottle conditioning: Wait at least two weeks after bottling to put your beer in the fridge. Leave bottles in a cool (but not too cold!), dark place in the meantime. I know you want to drink your beer now but waiting will give the beer deeper, more complex flavors and aromas, in addition to keeping your yeast happy.
- Finished beer: Refrigerate to maintain the freshness of your hard-earned beer. It is as susceptible to oxidation or lightstrike as mass produced and craft beer. At minimum, store in a cool, dark place like the corner of a basement.
As with commercially available beer, temperature and time combined are what contribute to the freshness of beer.