How Heat Affects Keg Beer

Keg is a popular choice for many beer enthusiasts, as it allows for larger quantities of beer to be served and enjoyed. However, one common concern among keg beer consumers is what happens if the beer gets warm. Does keg beer go bad when it's not kept at the optimal temperature?

The short answer is yes, keg beer can go bad if it gets warm. The quality and taste of the beer can be greatly affected by fluctuations in temperature. Let's take a closer look at why this happens and what you can do to prevent it.

First and foremost, it's important to understand that keg beer is typically unpasteurized, meaning it hasn't been heat-treated to kill off any bacteria or present in the beer. This is what gives keg beer its fresh and flavorful taste. However, it also means that the beer is more susceptible to spoilage if not stored properly.

When keg beer is exposed to warm temperatures, it creates an ideal environment for bacteria and yeast to thrive. This can result in off flavors, sourness, and even a spoiled taste. Additionally, warm temperatures can cause the beer to become overcarbonated, leading to excessive foaming and a loss of flavor.

To ensure that your keg beer stays fresh and delicious, it's crucial to store it at the recommended temperature of around 38 degrees Fahrenheit (3 degrees Celsius). This temperature helps to inhibit the growth of bacteria and yeast, preserving the quality of the beer.

If you're hosting a keg party or event, it's essential to have a reliable method of keeping the keg cold. This can be achieved through the use of a kegerator, which is a specialized refrigerator designed to store and dispense keg beer at the optimal temperature. Alternatively, you can use a large bucket filled with ice to keep the keg cold, ensuring that it stays within the recommended temperature range.

Another factor to consider is the type of beer you're serving. Different styles of beer have different temperature preferences. For example, lighter beers such as lagers and pilsners are best served at colder temperatures, while darker beers like stouts and porters can be enjoyed at slightly warmer temperatures. It's important to refer to the specific recommendations for each beer style to ensure the best taste and quality.

Keg beer can indeed go bad if it gets warm. The unpasteurized nature of keg beer makes it more susceptible to spoilage when exposed to higher temperatures. To maintain the freshness and flavor of your keg beer, it's crucial to store it at the recommended temperature of around 38 degrees Fahrenheit. By doing so, you can ensure that your keg beer remains enjoyable for a longer period of time.

How Long Can Keg Beer Sit Unrefrigerated?

Keg beer should ideally be refrigerated at all times to maintain its freshness and quality. However, if for some reason the keg is left unrefrigerated, the beer's lifespan will be significantly reduced. The exact duration that keg beer can sit unrefrigerated depends on various factors such as the type of beer, the temperature it is exposed to, and the level of carbonation.

In general, keg beer should be consumed within 8-12 hours if it is kept at room temperature (around 68-72°F or 20-22°C). Beyond this timeframe, the beer may start losing its carbonation and flavor, becoming flat and less enjoyable to drink.

If the ambient temperature is higher, the deterioration process will be accelerated. For every 10°F (5.6°C) increase in temperature, the beer's shelf life decreases by approximately half. Therefore, if the keg is exposed to temperatures above 80°F (26.7°C), it is recommended to consume the beer within 4-6 hours.

To summarize, here is a breakdown of the recommended timeframes for consuming keg beer when left unrefrigerated at different temperatures:

– Room temperature (68-72°F or 20-22°C): Within 8-12 hours
– Elevated temperature (above 80°F or 26.7°C): Within 4-6 hours

It's important to note that these timeframes are approximate and can vary depending on the specific beer and other environmental factors. To ensure the best drinking experience and avoid spoilage, it is always advisable to keep keg beer refrigerated whenever possible.

does keg beer go bad if it gets warm

How Do You Know If Keg Beer Is Bad?

There are several signs that can indicate if keg beer is bad. Here are some things to look out for:

1. Foul taste: The most obvious red flag is a foul taste. If your beer tastes off, with flavors that are unnatural or unpleasant, it could be a sign that the keg is bad. The taste may be overly sweet, resembling ripe apples or other fruit. On the other hand, it could taste like sulfur, which is highly undesirable.

2. Strange odor: In addition to the taste, the aroma of the beer can also provide clues about its quality. If you notice any unusual or unpleasant odors, such as a strong sulfuric smell, it's a warning sign that the keg may be spoiled.

3. Cloudy appearance: Good beer should have a clear and transparent appearance. If you pour a glass from the keg and notice that the beer is cloudy or hazy, it could be an indication of spoilage. Cloudiness can be caused by various factors, including bacterial contamination or yeast sediment, both of which can affect the taste and quality of the beer.

4. Excessive foam or lack of carbonation: When pouring beer from a keg, it should have an appropriate amount of foam and carbonation. If the beer produces an excessive amount of foam, it may be a sign of an issue with the keg, such as an infection. Conversely, if the beer lacks carbonation and is flat, it could mean that the keg has gone bad or hasn't been properly stored.

5. Off-flavors or off-color: Pay attention to any off-flavors or off-colors in the beer. If the beer tastes or looks different from what you would expect, it's likely that something is wrong with the keg. Off-flavors can range from metallic or sour tastes to astringent or vinegary notes. Similarly, if the color of the beer appears abnormal, it may indicate spoilage.

6. Expiration date: Check the expiration date on the keg. If the beer is past its expiration date, there's a higher likelihood that it has gone bad. While beer can still be drinkable after the expiration date, it's best to be cautious and evaluate the other signs mentioned above.

If you encounter any of these signs, it's advisable to avoid consuming the beer from the keg. It's better to be safe than sorry when it comes to spoiled beer, as it can lead to an unpleasant drinking experience or even illness.


Keg beer is a popular choice for many beer enthusiasts due to its convenience and ability to provide fresh, draft-quality beer. However, it is crucial to handle and store kegs properly to maintain the quality and taste of the beer.

One of the key factors in preserving the quality of keg beer is ensuring that it is stored at the recommended temperature. Keeping the keg at or below 38 degrees Fahrenheit is essential to prevent the beer from becoming foamy and developing a stale flavor. Additionally, it is important to note that unpasteurized domestic US beers, which make up a majority of keg beers, should not be stored above 50 degrees Fahrenheit to prevent bacterial growth and spoilage.

Another indicator of a bad keg is a foul taste. If the beer tastes unnaturally sweet with a hint of ripe fruits or has a sulfur-like taste, it is a clear sign that the keg is no longer good. These strange flavors can be a result of oxygen exposure or other factors that cause the beer to go flat and spoil quickly.

To fully enjoy keg beer, it is crucial to consume it within 12-24 hours, depending on the type of beer and the amount of oxygen pumped into the keg. After this time frame, the beer will lose its freshness and may develop off-flavors. Therefore, it is important to plan accordingly and only tap a keg when you have a sufficient number of people to consume it within the recommended time.

Keg beer offers a unique and enjoyable drinking experience, but proper handling and storage are essential to maintain its quality. By keeping the keg at the correct temperature and consuming it within the recommended time frame, beer enthusiasts can ensure that they are getting the best flavor and freshness from their keg beer.

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Thomas Ashford

Thomas Ashford is a highly educated brewer with years of experience in the industry. He has a Bachelor Degree in Chemistry and a Master Degree in Brewing Science. He is also BJCP Certified Beer Judge. Tom has worked hard to become one of the most experienced brewers in the industry. He has experience monitoring brewhouse and cellaring operations, coordinating brewhouse projects, and optimizing brewery operations for maximum efficiency. He is also familiar mixology and an experienced sommelier. Tom is an expert organizer of beer festivals, wine tastings, and brewery tours.