Oxygen Uptake in Beer Bottling Modern bottling technology as an answer to well-known challenges

Brewers know: Beer is probably the beverage most sensitive to oxygen. The so-called oxidation taste occurs when the oxygen intake is too high.

Trend beers with the rediscovered dry hopping, formerly known as “dry hopping”, change their taste very quickly when they absorb oxygen. But ordinary light beers are also particularly sensitive to oxygen. Darker beers, on the other hand, often show a considerable taste tolerance to oxygen levels above 0.1 mg/l.

Oxygen absorption during beer brewing begins when the malt is crushed and does not end when the beer leaves the brewery, because oxygen penetrates the seals of crown caps, for example, right up until the point at which the beer is consumed. Beer ingredients react so quickly with oxygen that dissolved oxygen measurements are required immediately after the respective processes such as tank filling, filtration or bottling. An oxidized beer with the typical changes in taste often has hardly any measurable oxygen content, and yet the quality losses are clear.

The use of additives such as bisulfite or ascorbic acid as oxygen scavengers is common in other countries outside of Germany, especially for filling PET bottles. Because these containers and the most commonly used closure made of PE or PP allow oxygen to migrate in relevant quantities in a short time. However, as an antioxidant for beer, ascorbic acid is a double-edged sword. Oxidation processes - not only in beer, but also in other beverages such as soft drinks or juices - are complex processes with many intermediate stages, and thus much more than the transfer of oxygen to a specific recipient molecule. Are the polyphenols in malt or hops beneficial antioxidants or harmful clouding agents? This is a chapter in itself. In order to meet this challenge, breweries are developing different approaches to quality assurance: from malts low in polyphenols to polyphenol-rich cone hopping or strategies for preservation through precipitation to reduction of polyphenols using PVPP.