Helping Your Beer Last Longer with Chromatography

The landscape of beer drinking was very different thirty years ago. You had to drink the local brew in your local pub — that was all they sold. If you wanted a different tasting lager or bitter you went to a different pub owned by a different brewery. Today’s beer drinkers are spoilt for choice. Microbreweries, guest ales and continental lagers offer greater choices and flavours than ever before.

The choice has created discerning modern drinkers — they know what they like and when it doesn’t taste good — and unlike drinkers of the past they can vote with their feet and their money. So flavour consistency is of paramount importance. Brewers have to make sure their ales are consistently good, and because they often travel outside their local areas — including internationally — new problems have arisen for modern brewers. How can they keep ales fresher for longer — increase the shelf-life — so they travel and can be stored for longer without losing quality and taste?

Flavour Stability

As soon as a beer leaves the brewing area it starts to age and its flavour begins to change. Brewers need to understand how their ales age — and this means knowing the ingredients. How do the different components that go into making an ale behave and change as they get older?

Pinning down exactly how and why beer flavours change is still not fully understood — there are hundreds of different compounds that combine to make the flavour of your beer  — and depending on the recipe and storage conditions they will change at different rates. Warmer storage conditions generally lead to beers that age quicker, and small changes in the initial beer acidity can affect how well a beer lasts in the bottle or keg.

Using chromatography, researchers have managed to identify some of the changes that take place in beers that contain hops and this could help brewers make beers that taste fresher for longer.

Hop to it

Hops — female flowers of the Humulus lupulus plant — are widely used as a flavouring, aroma and stability agent in many beers, they also have antimicrobial and antioxidant properties. They impart a bitter taste that can balance the sweetness of other ingredients such as malt — and by altering the amount and type of hops used, brewers can alter the flavour of their beers. The degradation of the hops, and in particular the hop’s iso-alpha acids, is one of the reasons for changes in beer flavour.

The hop alpha-acids are isomerised and exist as cis- and trans- isomers. But the isomers have different energy profiles, like many isomers, and so degrade at different rates. Brewers can measure the ratio of the trans/cis iso-alpha acids using high performance liquid chromatography (HPLC) to give an indication of how a beer has aged.

To find out how the use of HPLC and GC helps to make Jägermeister such a special drink have a look at this article, Jägermeister – Quality You Can Taste, on the Chromatography Today website.