As an experienced sommelier and brewer, I can confidently say that it is indeed recommended to refrigerate growlers. While growler caps are designed to provide a fairly airtight seal, they are still not intended for long-term storage. Therefore, it is best to refrigerate them to maintain the freshness and quality of the beer inside.
When growlers are filled with fresh beer, they are typically not pasteurized or filtered like commercial bottled or canned beer. This means that the beer is more susceptible to spoilage and degradation over time. While the airtight seal of the growler cap helps to minimize oxygen exposure, it is not foolproof.
By refrigerating the growler, you can slow down the oxidation process and help preserve the flavors and aromas of the beer. Cold temperatures also inhibit the growth of bacteria and other microorganisms that may affect the quality of the beer.
I have personally experienced the difference in taste and quality when storing growlers at room temperature versus refrigerating them. When a growler is left at room temperature for an extended period, even if the cap is tightly sealed, I have noticed a gradual decline in the beer's freshness and vibrancy. However, when I refrigerate a growler, the beer retains its flavors and aromas much better, allowing me to enjoy it at its best.
To further emphasize the importance of refrigeration, it is worth noting that many breweries recommend consuming growler beer within a few days of purchase. This is because the beer is typically filled directly from the tap, which introduces some oxygen into the growler. While the airtight cap can help slow down the oxidation process, it cannot completely prevent it. Therefore, refrigerating the growler becomes even more crucial to preserve the beer's quality for as long as possible.
Refrigerating growlers is highly recommended to maintain the freshness and quality of the beer. While the airtight caps help minimize oxygen exposure, they are not meant for long-term storage. By refrigerating the growler, you can slow down the oxidation process, inhibit bacterial growth, and enjoy the beer at its best.