Warm beer is beer that has been allowed to come to room temperature after being refrigerated. This is an undesirable state for beer, as the flavor profile can quickly deteriorate once the liquid warms up. However, sometimes beer might accidentally or intentionally become warm. This leads many beer drinkers to wonder – how long is it safe to drink warm beer before it spoils?
What happens when beer gets warm?
Beer is best stored cold, between 38 and 45 degrees Fahrenheit. When beer warms up, a few negative things begin to happen:
- Volatile aromas and flavors dissipate – The appealing hoppy, malty, and fruity notes start to fade.
- Dissolved carbon dioxide is lost – Carbonation bubbles escape, leading to flat, stale tasting beer.
- Oxidation occurs – Oxygen reacts with compounds in the beer, leading to off-flavors.
- Contaminants can grow – Bacteria and wild yeasts can multiply at warmer temperatures, spoiling the beer’s flavor.
The higher the temperature and the longer the beer sits warm, the more pronounced these detrimental effects become. So it’s best to drink or re-chill beer soon after it warms up.
How long can warm beer last before going bad?
There is no definitive shelf life for warm beer. How long it lasts depends on multiple factors:
- Beer style – Lagers and lighter beers deteriorate faster than ales and higher-ABV beers when warm.
- Ingredients – Beers with more hops and complex malt profiles degrade quicker.
- Alcohol content – Higher alcohol levels help preserve beer for longer.
- Temperature – The warmer the temperature, the quicker the beer goes bad.
- Packaging – Draft beer lasts longer than bottled or canned beer once warm.
- Freshness – Older beer has less shelf life than freshly brewed beer.
As a general guideline:
- Pale lagers and ales should be consumed within 4-8 hours of warming.
- Amber/brown ales and bocks may last up to 12 hours warm.
- Stouts, porters, and belgian beers can potentially last 24 hours warm before noticeable deterioration.
However, these are very rough estimates. Flavor degradation can begin within just a couple hours of a beer warming up. Whenever possible, it’s best to re-chill beer to optimal serving temperature rather than letting it sit warm too long.
How to tell when warm beer has gone bad
Here are some signs that indicate warm beer has spoiled and should no longer be consumed:
- Flat, lackluster carbonation
- Cardboard, papery stale flavors
- Butter, butterscotch oxidation flavors
- Metallic, tin can flavors
- Soapy, bubblegum flavors
- Vinegar, sour acetic acid flavors
- Funky, barnyard wild yeast flavors
- Skunky, lightstruck flavors
- Cloudiness or particles floating in the beer
If you notice any combinations of these undesirable flavors or textures, the warm beer has likely spoiled and should be discarded. When re-chilled beer tastes noticeably different than it did originally, it has gone over the hill.
Preventing beer from warming in the first place
While warm beer deterioration is unavoidable at times, a few proactive steps can help keep your beer cold until you’re ready to drink it:
- Keep unopened beer stored in the fridge or cool basement until you plan to consume it.
- Pour only the amount needed into glasses or mugs instead of leaving open bottles/cans out.
- Keep beer on ice or refrigerated as much as possible during transport.
- Drink beer within a reasonable time frame after serving and don’t let glasses/cups sit out long.
- Invest in good beer glassware and mugs with insulation to slow warming.
- Use refrigerated glassware to minimize warming as you drink.
- Swirl beer before sipping to release aroma and flavor compounds.
While exposure to higher temperatures is inevitable at times, being mindful of beer temperature and using chilled glassware can help maximize the flavor and enjoyment of your brews.
What to do with warm, flat beer
If you have beer that has warmed up and gone flat, don’t necessary pour it out. Here are some clever ways to use up warm, flat beer:
- Make beer batter – Use flat ale or lager to make fried food coatings crispy.
- Simmer in stews or chili – The beer adds savory flavor to hearty dishes as it cooks down.
- Deglaze a pan – Warm beer can help scrape up browned flavorful bits from pans.
- Use in marinades – The acidity and flavors in warm beer can tenderize and flavor meats.
- Make beer vinegar – Allow bacteria to ferment warm beer into tangy vinegar over time.
- Water plants – The minerals and yeast in flat beer can help fertilize gardens.
So instead of pouring old warm beer down the drain, get creative and use it to add complexity and flavor to cooking!
Frequently Asked Questions
What temperature does beer start to go bad?
Once beer exceeds 45 degrees Fahrenheit, its quality and freshness begins deteriorating. The warmer the temperature it reaches, the faster it spoils.
Does putting beer in the freezer ruin it?
Freezing beer below freezing, around 30-25 degrees, can actually help preserve it over time. However, freezing at very low temperatures like below 20 degrees can cause haze issues. The liquid also expands when frozen, which can break bottles if left unchecked.
Can you get sick from drinking warm, old beer?
Consuming very old, spoiled warm beer is unlikely to make you sick. However, beer left sitting out for many hours can start growing harmful bacteria and develop poor flavors. Trust your senses – if beer smells or tastes clearly bad, it’s best to discard.
Why does tapping a beer bottle help with foam?
Gently tapping the side of a beer bottle releases dissolved CO2 gas trapped in solution, which forms bubbles that help generate a frothy foam head when poured. However, tapping won’t help flat beer that has already lost its carbonation.
Should beer be stored upright or sideways?
For bottled beer, sideways storage is best as it keeps the beer in contact with the cap, reducing oxygen exposure. Canned beer and kegs can be stored either way. But all beer should ultimately be stored cold and away from light.
The Bottom Line
Warm beer quickly loses its appealing aroma, flavor, and carbonation the longer it sits. Pale lagers and ales should be consumed within 4-8 hours, while darker ales may last up to 24 hours before noticeable deterioration. Monitor the taste and watch for stale, sour, or funky flavors. When possible, re-chill beer to optimize its flavor. And you can use warm, flat beer creatively in cooking rather than pouring it out!
