It’s like that with the canned beer. Some swear by it, others just turn up their noses – because its reputation isn’t the best. For many, quality and tin do not go together. But are they correct? A research team from Colorado State University did the check: can or bottle – which keeps the beer fresher longer?

The researchers selected types of beer that are currently particularly popular in the USA – Amber Ale and IPA. The brown beer bottles and the beer in cans were then initially stored in a cool place for a month and then at room temperature for five months. Just like beer is typically stored before it reaches the consumer. A bottle and a can were then opened every two weeks for six months and tested for freshness and taste.

The focus was on the (still) existing concentration of the most important chemical compounds that give the beers their unique taste. Often these compounds include amino acids, terpenes, and esters, which gasify more quickly and decompose on storage. The beer gradually loses more and more of its taste.

The result surprised. As it turned out, it is not just the vessel that determines the question of how fresh it is, but the type of beer in combination with the vessel. “Taken together, the results of this study do not suggest that there is one universally best packaging for all beer styles, but rather show that the effects of packaging type are dependent on the beer style,” the scientists conclude.

The Amber Ales tested, such as London Pride, stayed fresh longer in the bottle. When it was canned, the concentration of certain chemical compounds was already lower when it was opened than in bottled ale. One explanation for this could be the manufacturing process. This could lead to oxidation reactions in the can, since air is trapped in the can. In the case of bottled beer, on the other hand, this air is extracted using vacuum filling systems.

So-called “flavor scalping” also plays a role. This describes a loss of quality that is either due to the packaging absorbing flavors or the packaged contents absorbing flavors from the packaging. This is the case with plastic bottles, for example, but probably also played a role in canned ale.

With the IPA, on the other hand, the US researchers could not find any relevant qualitative difference between the beer from the bottle and that from the can. This is explained, among other things, by a higher polyphenol content in the IPA, which on the one hand counteracts the oxidation processes mentioned and on the other hand binds chemical compounds that give the taste. So they evaporate less quickly.

Quelle: ACS Food Science