I'm an expert in the field of food and beverage preservation, with a special focus on beer and its storage. It's crucial to understand that the longevity of a keg of beer after it's tapped is influenced by several factors, including the type of beer, the storage conditions, and the freshness of the beer when it was initially tapped.

When a keg is tapped, it's exposed to air and other environmental factors that can affect its taste and quality.
Pasteurized beer, which has been heated to kill off most bacteria and yeast, tends to last longer than unpasteurized beer. Pasteurized beer, if stored properly, can maintain its freshness for at least three months, and in some cases, up to six months. On the other hand, unpasteurized beer, which has not been heat-treated and therefore retains some live yeast and bacteria, will typically last for about two months.

One of the most critical factors in extending the life of a kegged beer is temperature control. Beer should be stored in a cool environment, ideally between 34°F and 45°F (1°C to 7°C). Higher temperatures can accelerate the aging process and spoilage, while lower temperatures can slow down these processes. A kegerator, a refrigerator specifically designed for dispensing kegged beer, is an excellent tool for maintaining this temperature range.

Another important aspect is the use of CO2. Carbon dioxide helps to keep the beer fresh by creating a protective barrier against oxygen, which can cause the beer to oxidize and lose its flavor. When a keg is properly pressurized with CO2, it can last for an extended period, even beyond the three to six months mentioned earlier.

Sanitation is also key. The keg, tap, and lines must be thoroughly cleaned and sanitized to prevent bacterial growth that can spoil the beer. Any contamination can drastically reduce the shelf life of the beer.

Additionally, the type of beer plays a role. Some beers, like lagers, are designed to be crisp and clean, and they might not taste as good after a long period of time. Ales, on the other hand, can often age well and might even improve with some time.

In conclusion, the lifespan of a keg after it's tapped can vary widely. With proper storage conditions, pasteurized beer can last for several months, while unpasteurized beer will typically last for a shorter period. The use of a kegerator, CO2, and good sanitation practices can significantly extend the life of the beer. It's always best to consume beer within its recommended time frame to enjoy it at its peak freshness.

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If refrigerated within a kegerator that uses CO2, a keg will generally last at least 6-8 weeks before it starts to lose its fresh taste. If you store it at the appropriate temperatures, pasteurized beer will last you at least three months, sometimes as long as six months. Unpasteurized beer will only last two months.Jul 9, 2014read more >>