In contrast to brown bottles, green glass poses a more significant threat to beer’s integrity. “Green glass does not block out certain wavelengths of light and can lead to beer becoming lightstruck if exposed to sunlight, leading to a signature skunky aroma,” Tyler clarifies. This process results in the development of off-flavors, which many beer enthusiasts aim to avoid. However, if you’re loyal to Stella Artois, Rolling Rock, Heineken, or any other brand in emerald containers, you likely don’t mind the pungence.
The scientific explanation for this optical phenomenon involves the interaction between UV light and the hops used in brewing. Hops, the flowers that contribute to beer’s bitterness, contain compounds called isohumulones. When exposed to UV light, isohumulones undergo a reaction that produces the compounds responsible for the unpleasant scent. Brown bottles act as a shield.
Considering the pitfalls of glass, it makes sense that the popularity of canned beer continues to rise. Tyler points out one of the reasons it tastes better than bottled beer. “Cans have a lot of pros,” he admits. “They are lightweight, not breakable like glass, easy to recycle (mostly), but most importantly, let in zero light, which keeps beer freshest longest.” Aluminum cans have become a preferred choice for some breweries. Unlike bottles, which expose beer to some degree of light, the cans provide an impermeable barrier. This ensures the beer stays in optimal condition until the can is opened.