Is beer more stable in cans or bottles?

Since the flavor of beer begins to change as soon as it is packaged, scientists have long wondered if this type of beverage stays fresher in bottles or in cans. Now, a team of researchers from the Colorado State University (CSU) has found that the answer to this question depends on the type of beer. For instance, while an amber ale remained fresher in bottles, container choice made much less difference to the stability of Indian Pale Ale (IPA).

Besides water and ethanol, beer contains thousands of flavor compounds produced by yeast, hop, and other ingredients. Since during storage, chemical reactions break down some of these components while forming others, the content of some tasty flavors is reduced, contributing to the aging, or staling, of beer. Although researchers have already studied beer aging in order to help brewers prolong shelf life, they focused mainly on light lagers and a limited group of chemicals. Now, the CSU team extended the analysis to amber ale and IPA, while comparing the stability of beer packaged in glass bottles versus aluminum cans.

To mimic typical storage conditions, the scientists chilled cans and bottles of amber ale and IPA for a month and then kept them at room temperature for an additional five months, while analyzing every two weeks the metabolites in newly opened containers. During this period, the concentration of metabolites in amber ale, such as several amino acids and esters, was significantly different depending on the type of packaging. By contrast, IPA appeared less sensitive to packaging type, most likely due to its higher concentration of polyphenols from hops, which prevent oxidation and help retain amino acids in the beer for longer.

The analyses also revealed that, while the metabolic profile of both kinds of beer changed over time, regardless of the type of packaging, amber ale in cans showed the greatest variation during aging. Further research is needed to clarify how such changes affect flavor in order to help brewers make more informed decisions on what kind of packaging to use for the particular types of beers they produce.

“Taken together, the results of this study do not support the conclusion of a general best package for all beer styles but rather indicate that the effects of package type are dependent on beer style. Continued work to define the mechanisms driving the effects of package type on beer stability is warranted and would require integration with sensory outcomes. Ultimately, research on beer stability and packaging should provide relevant knowledge, so brewers may make scientifically backed packaging decisions and shelf-life determinations,” the authors concluded.

The study is published in the journal ACS Food Science & Technology.

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By Andrei Ionescu, Earth.com Staff Writer

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