Friday 29 June 2012

Stale Keg

The post preceding this and some comments on Boak and Bailey's blog have mentioned stale keg beers. It got me wondering. Now I know a little about why this should occur, but very little about how often it occurs, or even, if and when it does occur, whether anyone actually notices it.

It must be difficult, even with the best will in the world, to transport kegs of beer from the farthest corners of, say, the USA, without the beer suffering some deterioration in the process. Nor am I sure if such exports are in the main pasteurised or not. Given the number of stale or staling beers I've had in the US, I suspect most are not.  There is also I believe, a wide spread belief that keg beer is somewhat immune to deterioration and I wonder whether that, combined with unfamiliarity with the same product drunk fresh, allows or even encourages palates to be fooled.

I drink almost no keg imports here, so am not really qualified to do other than speculate. What do people that do think?

The little diagram is interesting and informative, though hardly conclusive. It should keep some folks (guess who) happy for a bit. Click on it to read properly.


Adrian Tierney-Jones said...

One of my earliest Morning Advertiser gigs was to write about a Stella Artois quality control scheme, which I thought superfluous as I thought keg lasted for decades, but imagine my surprise when licensees told me that keg could go stale. I love a lot of craft keg but you still have to look after it, have had both indifferent and glorious Brooklyn Lager — for me it’s not about a war between cask and keg but about licensees having the nous to look after their beer whatever way it erupts out of the funnel.

Bailey said...

It's rare for us to have a *really* off beer from keg, but it does happen.

More commonly, we find them slightly muted compared to the bottled version.

Pilsner Urquell, however, usually seems pretty vibrant from keg, though not a patch (of course) on drinking it in Prague. The various beers we had from keg at the Craft Beer Company was also really 'zinging', but then they probably get through the stuff pretty quickly, given how busy it seems to be most of the time.

Maxwell Power said...

I've had bad pints of Guinness Caffreys, JS Smooth before (long ago before my real ale awakening).

I don't know whether this could've been attributed to a stale keg or, and probably more likely, a lack of line cleaning possibly?

Phil said...

I had a half of BD Hops Kill which was so sour I would have taken it back if it had been on cask; since it was on keg I assumed it was meant to taste like that. Maybe not!

Anonymous said...

critch the brewer....

once breached a keg has a life of a mere 7 days according to the cellarman course i did when i ran the pub, always found that was a little conservative and could get up to 2 weeks before noticing product deteriationaidrians spot on with what he said imo

regards, critch

Dominic, Thornbridge Brewery said...

All fermented beer will start to deteriorate once the beer has been filtered or clarified, i.e. prepared for packaging. So when the beer is put in the keg, it's already going downhill.

Oxygen combines with other materials in the beer to form compounds which don't taste nice, i.e. stale. The amount of dissolved oxygen varies between each beer and depends on how the beer has been handled since it completed fermentation. So beers deteriorate at different rates. There is no 'one size fits all' time lapse for beer going stale. Breweries vary in both their ability to control dissolved oxygen and their understanding of its role in beer deterioration. Breweries unused to the preparation of bright beer (i.e. those that usually make cask beer) often struggle to understand dissolved oxygen level elimination and process control and therefore inadvertently produce beer ready for staling.

Pasteurisation accelerates the beer staling process because heat increases the compound-forming reactions. So beer that has been pasteurised is more likely to taste stale. As pasteurisation also involves expensive equipment I doubt more than 0.1% of 'craft breweries' utilise it within their process. It's more for the big brewers who can't keep the beer making process clean.

Personally, I believe that most beer drinkers in the UK, used to incredibly high levels of dissolved oxygen in beer, cannot taste or are not too fussed by oxidised beer. For some however, it is the difference between a good pint and a shite pint. I have nothing to back this up with so it could well be horseshit.

To be honest with you, I find the problem is not oxidation but a dispense issue where the dispense line is dirty. Cask lines are generally cleaned fastidiously in most good beer houses, but as the 'craft keg' is so expensive, the cellarperson will not clean the lines as often or pour off half in the morning before service, so the first few pints of the day often taste of diacetyl and a hint of acetic acid. Many 'craft beer' bars are guilty of this and I find it more of a problem than an infected cask beer line.

Don't even get me f@#$ing started on oxygen and its role in haze formation. It's pretty much my favourite area of brewing science.

Bailey said...

This is an interesting interview with Charles Bamforth on poorly-kept keg beer and how to avoid it.

Tandleman said...


Really helpful comment and does tend to confirm what I suspect. It really does make me wonder though broadening it out, when you say "Personally, I believe that most beer drinkers in the UK, used to incredibly high levels of dissolved oxygen in beer, cannot taste or are not too fussed by oxidised beer. ", whether you mean all cask conditioned beer, poorly produced keg beers, or just all British beer.

Charlie Bamforth in his book the Art and Science of Brewing suggests that even now the role of oxygen in beer is incompletely understood pp68-69 and that it may well go as far back is the malting process. He has some good stuff too in oxygen and haze.

But before we say all cask beer is oxidised to buggery, Charlie at least is a great fan. He says so in the book.

B&B. I'll look at that as soon as I can. I am also a great fan of his and the book above (personally signed and sent to me with the dedication Peter.... Keep promoting Real Ale) is my bible when arguing technically, which I don't do that often.

Tandleman said...

PS - Dirty lines in keg houses. Hmm. If beer is sold at the equivalent of a tenner a pint or above, as well as routinely at over a fiver, you can see that they won't want to throw it away. Vicious downward quality spiral that.

It is well known in real ale circles that you don't ever hurry to be first at the bar at opening time. When we go on CAMRA bus trips, I always let the others rush in first. My beer comes fresh from the cask that way. Any beer man also knows that you politely hand the first pint poured to your mate. That way he or she gets the warm beer in the line. It's dog eat dog out there.

Same would apply to keg.

Rich said...

My first question when buying a beer from any pub/bar is always what's new/fresh? and/ or when did it go on? Too many pubs are overreaching themselves with too many lines at the moment and inevitably some lines/beers don't sell anything like quick enough. Very interesting talking to Lee Chase at the Blind Tiger when we were in San Diego, he had fitted out their bar will all stainless fittings to minimise any chance of taint and also installed very short lines on each tap which could be changed easily and regularly. There's nothing worse than ordering a pale ale or IPA that tastes acidic or phenolic because despite the best efforts of the landlord a previously slow moving beer has tainted the line...

Professor Pie-Tin said...


" It is well know in real ale circles that you don't ever hurry to be first at the bar at opening time. "

Tight bastards !

Rich said...

Sorry 'Blind Lady', not 'Tiger' for the sake of accuracy

Tandleman said...


Tight bastards indeed.


I suppose that will just make it better, not stop it.

Dominic, Thornbridge Brewery said...

I was referring to cask ale. I also don't need Charlie to recommend it to me! The old adage of selling a cask within three days, good cellar practice, such as hard pegging when not in service hours and keeping everything scrupulously clean holds true. Of course, a good secondary fermentation in cask is also a good idea for reduced oxygen levels.

I deliberately stayed away from hot-side aeration because the scientists keep changing their mind with how important it is and I wanted to avoid copying out of text-books. Our Steels masher can be purged with CO2 prior to mashing in etc etc, but I reckon that as long as you don't splash it about too much on the way to the copper than there ain't much to worry about. Dissolved oxygen pick up post-fermentation is the important one.

Rich said...

Mine was more a general comment on why keg can be bad, although I would guess that tainted lines and bars not pulling through beer that's been sat in the line are a bigger culprit of poor quality keg than old or stale beer.

StringersBeer said...

My pal the professor is a fan of that arrangement you get in some bars where the taps are on the back wall of the bar with the "cellar" directly behind that. This means that the server has to turn their back on the customer (bad? what of the "theatre of the serve"?) but it means that the beer lines are really short, making them not only easy to clean and cool, but economically replaceable.

Curmudgeon said...

"It is well know in real ale circles that you don't ever hurry to be first at the bar at opening time."

It used to be often said that you shouldn't touch the Mild in Robbies' pubs before about half-eight in the evening.

The Traveller's Rest at Flash near Buxton used to claim to have - in keg form - every draught beer brewed in the UK. Probably an exaggeration, even in the 1970s, but it certainly had a bar lined with the box-type keg fonts typical of the period. I imagine many of those would have been pretty stale!

Erlangernick said...

Cheers, Dom, for the interesting input!

I'd never thought about taps mounted on the wall behind the bar as being strange or "unpub-ish" before, but being a Yank, it's normal to me. When the kegs are kept in a cooler behind the bar, it can lead to very short lines.

AFA the issue of pouring off the lines every day, this *is* important. And with the prices these beers have risen to compared to my years in Oregon...

One place that did it right was/is the Dublin Pub in Portland. No cask, but lots of keg. 104, in fact. I would occasionally find that a taster of something wasn't fresh, and I would assume this was due to the keg simply not having moved fast enough. But otherwise, it was like any other pub in terms of freshness.

Then the landlord died and his wife scaled back to 80. It's since been culled to 59, and the only photo I know of shows the current setup, but I don't get how it adds up to exactly 59:

Where there are now four shelves of booze, there used to be two. The lower two shelves occupy the space with four rows of 12 taps used to be. the boxes on the bar should house 16, as well as the section of panels between the cooler and the rows of 12. It was a fabulous place, and back then, a pint of something good and hoppy was maybe $3 or $3.50.

Has anyone here been there in the new millennium?