How should a growler be stored to maximize its shelf life after being opened?

To maximize the shelf life of an opened growler, it should be stored in a refrigerator and resealed. When beer is exposed to air, oxidation can occur, leading to undesirable flavors and reducing the overall quality of the beverage. By resealing the growler, you limit the beer's exposure to oxygen.

Refrigeration is important as it slows down the growth of any bacteria and helps to maintain the beer’s freshness and carbonation. Cooler temperatures also help preserve the hop character and other flavor components that can deteriorate if left at warmer temperatures. When beer is kept at room temperature or exposed to direct sunlight, it can undergo further degradation, affecting taste and aroma.

Storing the growler in a cooler without sealing it would still expose the beer to oxygen and potentially allow for temperature fluctuations, both of which would compromise the beer's quality. Thus, the best practice is to refrigerate and reseal the growler to help keep the beer fresh for a longer duration.