Beer and sensory science: the Aroxa flavour standards

Let's start with an apology; this post should have been published in December 2011. Something went wrong. I blame the organic lump at the end of the keyboard...

Whilst reading up about the science of beer taints, I found the aroxa website. This has a wealth of information on how tainted flavours originate, why they're important to recognise and, interestingly, which flavour notes professional tasters have mistaken for others.

One product that caught my eye was the beer uno kit. This offered ten flavour notes - four positive beer flavours, four off-flavours and two taints - which could be used to run a two-hour tasting session for ten people. And so a plan was hatched. Aroxa kindly donated me the kit; Thornbridge Brewery kindly rounded up some of their licensees and staff and so I ended up running a tasting panel session at their bar, DAda.

The mechanics of the session were very simple. Each flavour standard is a powder in a colour-coded capsule; the powder is dissolved into a jug of beer (we used a cask pale ale) and left for a couple of minutes to dissolve. Everyone had a tasting glass measure poured for them and then followed the assessment criteria for that standard (e.g. short sniff or sip & swallow).

Everyone shared their opinions of the flavours and aromas experienced and then we then talked through the information on the specification card that accompanied each flavour standard. These cover the importance and confusions data also found on the website plus details of the flavour's threshold and its chemical formula.

The tasting led to plenty of animated discussion. It was interesting to see how different people had different thresholds. Off-flavours were identified as issues encountered previously. And even the positive standards sometimes produced a negative reaction - "it smells too hoppy!"

Everyone agreed it had been a really useful insight into not only being able to experience the flavours and taints in a controlled environment but to learn more as to why it may be an issue - and what the likely cause could be.

This kit would make an ideal session for many brewers to run for their staff and the information cards and website backup could prove to be a valuable resource. Larger kits and single flavour standards - over a hundred of them - are available and cover cider, water and wine as well as beer.

I'd be more than happy to run the session for any brewer and their staff; get in touch if you want to know more.

Many thanks to Dr Bill Simpson from Aroxa for the beer uno kit and to Thornbridge for their time, beer and staff.


  1. looks a pretty top idea, actually with some of the new (and some not new!) breweries I've tried lately, it should perhaps be mandatory for brewers (assuming the info provided includes what actually causes the off flavours and how to avoid them!).

    Meanwhile, can I have a supply of the 'too hoppy' pills to take out with me and add to any twiggy beers I get served? ;-)

  2. It's more about identification & probable cause than remedy but it's an eye-opener. We had comments along the lines of one of the taints being a house style of a local brewer...

    ... and you could buy either pure hop oil or kettle hop aroma but you may find a portable randall works out cheaper ;-)

  3. for a lot of the faults there is no remedy, insofar as once its there you can't correct it. I meant more for brewers to identify the faults at quality control and therefore take steps to prevent repetition of whatever caused it

    yes, certain brewers are definitely known for what might otherwise be called an off flavour, I'd include Marstons sulpher among others...

    not sure I can see bars going for plugging in a portable randall, but a cafetierre (if that's how you spell it, bloody french...) and a handfull of hops could make a more practical alternative...