As a sommelier and brewer, I can confidently say that canned beer does have a longer shelf life compared to bottled beer. This is primarily due to the fact that cans provide a superior barrier against light and oxygen, which are two factors that can cause beer to spoil and deteriorate in flavor.
Light is one of the biggest enemies of beer, as it can cause a chemical reaction known as skunking. This occurs when the hops in beer are exposed to UV light, resulting in a distinct and unpleasant aroma similar to that of a skunk. However, cans completely block out light, providing optimal protection for the beer inside.
Oxygen is another enemy of beer, as it can lead to oxidation. When beer is exposed to air, it can react with oxygen, causing off-flavors and a stale taste. Bottles, especially those with twist-off caps, are more prone to allowing small amounts of oxygen to seep in over time. On the other hand, cans have a tight seal that prevents oxygen from entering, thereby slowing down the oxidation process.
However, it's important to note that while canned beer may have a longer shelf life, it does not mean that it lasts indefinitely. Like any perishable product, beer will eventually go bad. Over time, the flavors and aromas can degrade, resulting in a less enjoyable drinking experience. While some beer styles, such as high-alcohol and darker beers, can age and develop more complex flavors over time, most canned beers are intended to be consumed fresh.
The freshness of the beer also depends on how it was stored before and after purchase. If cans are exposed to extreme temperatures, such as being left in a hot car or stored in a freezer, it can negatively impact the quality and taste of the beer. It's always best to store beer in a cool, dark place to maintain its freshness for as long as possible.
In my personal experience, I have found that canned beers tend to hold up better over time compared to bottled beers. I have opened cans that were several months old and still enjoyed a flavorful and refreshing beer. However, I have also encountered cans that were past their prime and had a noticeable decline in taste.
To summarize, while canned beer does have a longer shelf life compared to bottled beer, it is not immune to going bad. The absence of light and the superior oxygen barrier provided by cans help slow down the oxidation process, allowing the beer to maintain its freshness for a longer period. However, it's always best to consume beer as fresh as possible to fully enjoy its intended flavors and aromas.