Cask breather or Aspirator


With beer volumes down over the winter months and the fact you must sell your lower alcohol (3.8%) real ale within three days, two days is better, this can become a struggle with Pubs who are quiet during the week. If you haven’t got one, why not consider using a cask breather or aspirator as they are sometimes called.

If you haven’t heard of them, they have been out for many years and have been tried and tested by the brewers.

What do they do?…….. Answer, they keep your beer fresher for a bit longer (usually a day).

And how do they do that?……..Instead of stale cellar air entering your container as the ale is drawn out, carbon dioxide (Co2) via a spigot in the shive, is replacing the liquid. This also works with upright stillaging using a pipe attached to the vent valve on the body of an ale extractor.


How do you get one?…….Ask for one, most of the major Brewers supply them as part of their commitment to provide you with quality cask ale.

(revision : I have been told by one of the Pub Co’s that the 4 major brewers no longer supply such equipment and that only certain regional’s now supply)

Cask Breather

However if you wish to remain in CAMRA’s good beer guide this avenue isn’t open to you.

Why ever not?………The argument is that carbon dioxide (fizzyness) is being added to the beer, which shouldn’t be a problem, if set right at a few pounds, normal blanket pressure (secondary fermentation occurs whilst in the cellar, this process makes its own carbon dioxide as it rises through the liquid, Co2 is heavier than air so it forms a blanket over the liquid and this helps to keep it fresh).

As any brewery technician will tell you the gas pressure has to be a lot higher to get absorbed into the beer and over longer period of time. I would like to bet that even a seasoned CAMRA drinker wouldn’t be able to tell the difference and anyway, would probably say it tastes fresher. They have been using one in my local for years and they don’t really need to, but they do, because of that very fact.

CAMRA’s answer would be to sell the beer quicker, but as we know in the real world things aren’t quite so simple.


Does a cask breather or aspirtator really affect the taste of the ale

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  1. All this Camra stuff gets on my nerves.Surely it doesn’t matter if you use aspirator or not.Provided the beer tastes as it should who gives a bugger.

      • That’s great!! I will tell all my customers that they can now use an aspirator and still be in the good beer guide.

        • Sadly the CAMRA Taliban have made themselves an increasingly irrelevant organisation who’s mantra of no change has isolated them from the real commercial world. All credit to them for saving our cask beer traditions yes but when new technologies come along that enhance the keeping of cask beers and are proven not to corrupt beer in anyway and they still stick to the “it’s not traditional” chant then sorry, that is just ridiculous. Lead lined pipes used to be the order of the day!

  2. I care a lot how my beer is kept and dispenced. I also think that if all this Camra stuff gets on your nerves , then you have no knowledge of what Camra have done for the Real Ale industry and in fact, if Camra hadn’t been formed there most probably wouldn’t be a real ale industry and you would be blowing the froth of of a lovely fizzy dead pint of Double Diamond or the like !!

  3. I agree with you both, if something isn’t done soon with the industry as it is there will be no pubs left to sell cask beers. The supermarkets can’t sell draught ales at the moment but it will be only a matter of time, they are already trying it in bottles. There will be some new inovation in the pipline I have no doubt. It is all well and good the micro breweries expanding, but they are subsidised to a certain extent by the bigger brewers with their delivery networks and equipment in place.

  4. We would of course sell our beer much quicker it we could get rid of the tie. In my pub we could sell a pint of any of our beers for about fifty pence less per pint if we were free trade and still make the same profit. Price of 9 gals of adnams from Pubco is 87.50 and from a free trade supplier 69.98

  5. I think frank is not knocking Camra,he seems to be saying they should be more relaxed.Surely provided Real Ale tastes good,looks good and is capable of being served in more outlets that is a good thing.
    Traditional methods of serving Cask Ale are great,but we should not have an embargo on new methods of keeping good ale.

  6. Aspirators are i great gadget, if they had them 100 years ago Camra,and the beardy ones would be ok about it then,i mean they drive cars surley they should walk or ride horses as this is the more “Trad” way of transport. What about more cask ale choice in Pins then there would be no need for Aspirator?

    • The system for using carbonic gas (as CO2 was called once over) to flood casks and prevent the beer going stale was suggested back in the 1800’s and a system was patented but for one reason or another never really caught on. tests carried out more recently over a six week period showed using a cask breather would significantly improve the shelf-life of a beer and in blind tastings was found to have no affect on the beer flavour other than maintaining it for longer. I would suggest all landlords whose turn over of a cask is greater than three days should be urged by the breweries supplying their beers to use aspirators and ignore CAMRA as there are far more pubs out there than ever get in the good beer guide and poor quality beer may be one reason why.

  7. I think that a lot of CAMRA’s former objections to cask breathers is because of a basic misunderstanding of how they work. Applying CO2 under pressure turns cask into Keg, ever heard this or something similar? Once used a cask of real ale needs to be used in app 3 days, because every pint you draw off is replaced by contaminated air, bacteria, yeasts, moulds, etc, not to mention Oxygen. The use of a cask breather introduces sterile CO2 therefore prolonging the life of real ale. A good cask breather does not pressurise the cask, it operates like an aqualung, releasing CO2 on demand ie in response to a slight vacuum caused by pulling the beer. Guess where CO2 comes from – breweries.I am now retired but my former Pub was in the good beer guide from 1989 to 2000. I kept a good selection of real ales including Mild but I could only get Mild in Kils (18 gals) no way to sell this in 3 days except on a busy weekend. I kept my cask breather very quiet and was awarded local CAMRA’s mild pub of the month on 3 occasions.

  8. I love hand pulled real ale and certainly don’t want it to be replaced by dreadful sterile pasturised keg beer! However this is not what a cask breather delivers. It enables a landlord to preserve and supply a fine tasting real ale (no fizz) that is alive, unpasturised, unfiltered and wonderful to drink. Surely the quality and taste of our fine product is all important? So what on earth is the problem that CAMERA has with a cask breather?

  9. I was wary of the cask breather until I started working in a club and got involved in the cellar work. They use aspirators because the opening hours are infrequent and irregular (run by unpaid volunteers). Once I understood the principles of cask conditioning and how aspirators work I realised that CAMRA’s objections were ill-founded.
    The problem is that they have got themselves hung up on the term “extraneous gas”. When CAMRA drew up its definition of real ale in the early seventies, “extraneous gas” was synonymous with pressure, as no other system existed (as far as I am aware) that didn’t deliver gas under pressure. So when the aspirator came along there was the predictable (fundamentalist?) reaction. No amount of subsequent explaining the mechanics has shaken this stance. They have collectively made up their mind beforehand to rubbish the aspirator and then have tried to make (up) the facts fit, or rather ignore them. Psychologists call it “confirmation bias”.
    I have yet to see any objective analysis setting out the mechanics and physics that can support CAMRA’s objections. Nebulous talk of it “not allowing the beer to condition and mature naturally” (naturally? What’s natural about beer?) is meaningless unless supported by a technical explanation, which it never is.
    The latest objection (straw clutching?) is that it encourages publicans to “keep their beer longer than intended”. Apart from the absurd implication that an otherwise conscientious landlord would turn into a rogue, where is the evidence? Even if this were true, and I doubt it very much, it is a management/training issue. Should we be objecting to the use of refrigerators in restaurants and pubs because they encourage food to be kept beyond its “natural” life? One could object to any technological innovation on those grounds!
    Which reminds me, if this is CAMRA’s unshakeable view, why is this same objection not applied to the Race Spile, which, it is claimed, can prolong the life of cask beer by three to five days? Doesn’t that tempt landlords off the path to righteousness as well? (I’m yet to be convinced that this works as claimed, but that’s another issue!)
    I do agree that aspirators shouldn’t be necessary where beer turnover is healthy. I suspect this is the case anyway as the equipment requires up-front investment. However, many pubs are struggling, as we all know, and the use of aspirators could be the difference between staying in business and closing.
    Sadly I suspect there are those “fundamentalists” within CAMRA who would be happy to say “Better dead than Red”.

  10. The company I work for manufacture this unit and this may sound crazy but the major customer response is they can actually get 20 days (some more) by using the aspirator system. Doesn’t help with making money but saves on wastage/money and reputation due to better quality beer served. Its a win win in my books.

  11. Why not replace the aspirator with a 0.22 micron sterile filter that will allow sterile air to enter the cask as beer is withdrawn. No contamination entering the cask resulting in longer shelf-life and no addition of extraneous carbon dioxide. Everybody happpy!

  12. That sounds like a good idea. I wonder what the costs might be in comparison with the initial cost of an aspirator? How long would the filter last? Certainly Camra might be happier!

Do you have a better answer? Leave a reply or an opinion