Does beer taste better from a bottle or a can?

How beer’s flavour is adapted, when packaged in a can or bottle, has been analysed in a new scientific study.

In a study by the American Chemical Society (ACS) in a report on ‘Food Science and Technology’, researchers decided to dig deeper into how beer begins to change as soon as it is packaged and how its flavour can change over time.

The research, which focuses largely on the beer’s longevity and freshness, identified that a verdict would always be “complicated” because it “depends upon the type of beer” but, during the study, the scientists still persevered to learn what would still affect flavour.

The researchers also outlined how, in addition to water and ethanol, beer contains thousands of flavour compounds, which are metabolites produced by yeast, hops and other ingredients. This means that, when beer is packaged, its chemical reactions break down some of those components while forming others — reducing some elements that are more flavoursome while generating a few unappealing flavours that make the beer taste stale.

The researchers stated that their goal was to help brewers prolong the shelf life of beer but warned that when people have studied beer ageing, many have previously only concentrated on light lagers and a limited group of chemicals to obtain the required results and few looked at a broad range of beer styles to illustrate the best methods for a repertoire of beers people now consume every day.

Researcher Jessica Prenni and her colleagues identified that they wanted to extend their work to amber ale and IPA and later down the line potentially a whole host of additional compounds – many that could be found in a range of craft beers. Additionally, the team also wanted to conduct a “stability comparison” for beer packaged in glass bottles versus aluminium cans.

In the study, cans and brown bottles of amber ale and India Pale Ale (IPA) were chilled for a month and then kept at room temperature for five months to mimic typical storage conditions. Then, every two weeks, researchers analysed the metabolites in newly-opened containers. During this time, the concentration of certain metabolites in amber ale — including some amino acids and esters — differed significantly depending on whether it was packaged in a bottle or can.

What the study found was that IPA proved to be much less sensitive to packaging type, possibly because of its higher concentration of polyphenols from hops. The scientists noted that these compounds not only helped to prevent oxidation but also assisted in binding to amino acids, thus retaining them in the beer rather than losing them inside the packaging.

The researchers also found that the metabolic profile of all the beers they studied showed an evolution of flavour over time, whether packaged in a can or bottle, but that ale in cans did show the greatest variation.

The findings ultimately indicated that amber ale certainly stayed fresher in bottles, whereas container choice made much less difference to the stability of  IPAs.

What this tells us is that the higher the hop content of a beer, the better its propensity to remain stable in any kind of packaging, provided light strike does not impact a glass bottle, tainting the brew. However, for more malt-led styles the beer responded better to glass and not aluminium cans.

This gives rise to the notion that, even though cans are easier to store and showcase brewery artwork, there is some argument to suggest that ambers, bocks, brown ales, dunkels and even porters right through to Belgian-styled dubbels, tripels and quadrupels would all do better in terms of flavour if served in glass bottles.

More research into sour styles of gose and gueuze and their stability as well as flanders and lambic beer is still needed for the evidence on coloured glass bottle vs. aluminium cans to be conclusive in the argument for “better” stability and “flavour”.