As an expert sommelier and brewer, I can confidently say that while refrigeration is preferable, it is not completely necessary for unopened beer kegs. However, it is important to consider the shelf life and quality of the beer when deciding on storage conditions.
Ideally, retailers should keep beer kegs refrigerated in order to maximize their shelf life and maintain the beer's freshness. Cold temperatures slow down the aging process of the beer, preserving its flavor and aroma. This is especially important for delicate and hop-forward beers, as heat can cause them to degrade more quickly.
When you purchase an unopened beer keg, it is recommended to keep it cold during transportation and storage. This will help maintain the beer's quality until you are ready to consume it. Storing the keg in a cooler or refrigerator is the best option, as it ensures a consistently cold temperature.
If a cooler or refrigerator is not available, you can still store the keg in a cool space such as a closet or basement. It is important to avoid extreme temperature fluctuations, as they can negatively impact the beer. For example, exposing the keg to hot temperatures and then chilling it suddenly can cause the beer to develop off-flavors.
In my personal experience, I have found that storing unopened beer kegs in a cooler with ice or gel packs works well. This helps to maintain a consistently cold temperature and ensures that the beer stays fresh for a longer period of time. However, I have also stored kegs in cool basements and had satisfactory results.
To summarize, while refrigeration is preferable for unopened beer kegs, it is not an absolute requirement. Keeping the keg cold during transportation and storage will help preserve its quality and extend its shelf life. Whether you choose to use a cooler, refrigerator, or cool space, it is important to avoid temperature fluctuations and provide a consistently cold environment for the beer.