Albert Einstein once said, “The important thing is not to stop questioning. Curiosity has its own reason for existing.” And while he probably wasn’t guzzling beers when he made that astute observation (or maybe he was—who knows?), you probably were when you looked at that bottle of IPA and wondered, “Why are beer bottles brown?” Fortunately for you and your Einsteinian mind, we spoke with Greg Taylor, professional brewer, cicerone and the business development manager at Fizzics (as seen on Shark Tank), and got all the answers.
Supercall: So, let’s get right to it. Why is my beer bottle brown?
Greg Taylor: It was very common for beer bottles to be green prior to the 1930s, but scientists later discovered that sunlight caused beer to break down or “skunk,” and brown bottles do a better job at keeping more harmful UV rays out.
SC: What is skunking?
GT: Skunking is caused when UV rays interact with the alpha acids dissolved in the beer, breaking them down to a compound that reacts with the sulphur in the beer to create a new compound (3-methyl-2-butene-1-thiol), which is almost identical to the actual smell that skunks spray on their predators.
SC: Are beers in clear bottles like Corona and Miller High Life more at risk of skunking faster?
GT: Newer hop products, such as Tetrahop extract, are chemically manipulated so as not to break down as easily in the presence of UV light. That is how some beers (i.e. Miller High Life) can get away with being packaged in clear glass, which offers no protection from sunlight. Although advanced, chemically altered hop extracts can help with skunking, they often do not offer the wide array of flavors and aromas of traditional hops. So ultimately, yes, clear bottles offer zero light protection and will cause the beer to skunk quickly. They are used mainly for marketing purposes to stand out.
SC: Why do companies like Heineken still come out with beer in green bottles?
GT: After WWII, brown glass was high in demand, and some breweries had to resort to using cheaper, clear glass bottles. Other higher quality brewers decided to use green bottles instead to make their beers stand out. This became a status symbol for several European brewers, which is why it is still common to see import beers in the green glass bottles, despite the fact that they do a poor job of blocking UV rays. Oftentimes the six pack holders will have cardboard shielding along all sides of the bottles for added protection because of this reason.
SC: Why choose glass over plastic or another material?
GT: Plastic PET bottles are used by many brewers across the world, but the downside is that plastic is more oxygen permeable than glass. Oxygen will speed up the aging or staling of beer, causing a papery, wet cardboard off-flavor.
SC: How should beer ultimately be stored, regardless of bottle color?
GT: Beer should be stored in a dark, cool environment without major temperature swings because even fluorescent light will degrade a beer packaged in glass bottles, and heat and oxygen will speed the staling of beer.