With summer picnic season in full swing, you may be assigned the most important job: bringing the beer! And with great power, comes great responsibility. Because there will be shelves and shelves of options at the local grocery store. You’ll have to decide on brand, style and even whether it’s in a bottle or a can.
Now the last choice may seem purely aesthetic, but it’s part of a much larger debate on the effect that the packaging has on the beer inside.
Can crusaders will tell you the light leaking through the bottles causes beer’s chemical compounds to decompose faster, resulting in a skunky aroma, while bottle boosters argue that cans leave a tinny taste and absorb heat from the environment too easily.
So what keeps it fresher – a bottle or a can?
It’s Complicated…
All beer is essentially water, ethanol and hundreds upon hundreds of flavor compounds. But those flavor compounds, which come from the unique combination of hops, yeast, malt, and any additives introduced by the brewer, are what give each beer its distinctive flavor profile. This profile obviously includes taste but also qualities such as aroma, color, clarity and texture. Each plays a key role in the experience of enjoying a beer.
So the way a beer keeps depends on the type of beer in addition to other factors including temperature, oxygen, light and natural metabolic processes.
Testing, Testing, 1…2…3
To start narrowing in the shelf life of a given beer, researchers from Colorado State University tested IPA and amber ale batches.
Both styles were housed in cans and brown bottles, and to replicate the storage conditions of a typical market beer, stored under cold conditions for 30 days and then at room temperature for 150 days. Then, every other week for over six months, the researchers opened a can and bottle of each style and analyzed their metabolites.
The Findings
Throughout this time, the concentration of certain metabolites in amber ale differed significantly depending on whether it was packaged in a bottle or can.
IPA, however, was much less sensitive to packaging, possibly because of its higher concentration of polyphenols from hops. These compounds not only prevent oxidation but also cling to amino acids, which allows them to remain in the beer rather than getting stuck to the inside of a container.
Researchers also found that the metabolic profile of both amber ale and IPA changed over time, whether packaged in a can or bottle. However, amber ale in cans showed the greatest variation during aging.
Once scientists find out how all of these changes affect flavor, brewers will be able to make more-informed decisions about the best type of packaging for a given type of beer.
In Conclusion…
Beer tastes best poured into a glass!
Our perception of flavor relies on a combination of senses – taste, smell, mouthfeel and sight. When you drink from a can or a bottle, your nose misses the beer! You cannot see the color of the beer or admire the foamy head. Put a beer in a proper glass, and you are getting the full sensory experience.