Cask-Conditioning

I was prompted to write this piece following an article which appeared on Tandleman’s blog, entitled “Improving with Age”. The crux of the post centred on the fact that cask-conditioned beer does actually improve when there’s a bit of time in the cellar for conditioning to actually take place. This is something I’ve always considered crucial to serving up a decent pint, but it’s something which is often over-looked particularly when it comes to maximising turn-over and keeping stock levels to a minimum.  

I’ve always been interested in the practical aspects of both brewing beer and looking after it once it’s been brewed and, without wishing to blow my own trumpet too much, I’ve had a fair amount of experience of both. With this in mind I decided to carry out a spot of research regarding the history and background to cask-conditioning, but surprisingly the various internet searches I conducted turned up very little. 

There are obviously publications and training manuals available regarding cellarmanship and cellar practice, many of which are the accumulation of many years experience in the field. In addition they are often specific to one particular brewery and its beers. But reasons why maturing beer in the cask became standard practice, and exactly how and when this process was first developed, seem lost in the mists of time. What follows therefore is very much my own take on this, and I would welcome input from other writers and industry analysts who will have far more knowledge than me on these matters. 

I strongly suspect the practice of cask-conditioning dates back to the time when beer, or even ale as it then was, was first kept in wooden casks, and that the maturation process was something which occurred almost accidentally. Many things improve with age, and beer is no exception. When “green” or immature beer is first racked into a cask, it still contains fairly high levels of suspended yeast cells. These would have continued nibbling away at residual sugars still present in the immature beer. In effect, fermentation was still continuing; albeit at a much reduced rate. The by-products of this process are a slightly increased alcohol content, alongside raised levels of CO2 gas within the beer. 

It is this dissolved carbon dioxide which gives condition to the finished beer, and this in turn provides much of the mouth-feel which is so desirable and satisfying to the drinker. It also contributes to the refreshing characteristics of the beer. As any beer drinker knows, a flat beer, totally devoid of condition, is not a pleasant drink and so this natural process and welcome by-product of continuing fermentation was something to be encouraged and indeed embraced.

As industrialisation increased and the use of glass drinking vessels became more widespread, the clarity of the finished beer became a far more important factor than it had hitherto been. Most beers will, of course, clear naturally left to their own devices, but depending on the yeast strain involved, this can sometimes be a lengthy process. Brewers therefore started to look at quicker ways to clarify beer.

The addition of isinglass finings was the first step along this path. Isinglass is a gelatinous protein prepared from the swim-bladders of certain fish. It works by attracting yeast cells, which carry a different electrical charge, causing the yeast cells to clump together and thereby dropping to the bottom of the cask by virtue of their size and weight. Other substances, such as gelatine have also been tried, but these proved less effective as, unlike Isinglass which has the ability to work several times over, they only work the once. As casks are normally shifted around several times between leaving the brewery and being handled in the pub cellar, this effectively rules them out, so isinglass remains as the default choice when it comes to clearing cask ale.

Wooden casks can even be used for lager

I would imagine that up until the mid-19^th Century, all bulk packaged beers were treated in a similar fashion, and that virtually all were cask-conditioned. However, at some stage around this time, especially with the move on the Continent to bottom fermented beers, things must have changed. Bottom fermented beers are matured for far longer periods than the more traditional top-fermented ales; with both fermentation and maturation taking place at significantly lower temperatures. These beers would eventually have cleared naturally, and during this time an appreciable amount of condition would have developed in the beer.

The next steps in the evolutionary process, particularly of bottom fermenting beers, would have been filtration and pressurised dispense. The former ensures perfect clarity in the beer, making sure the customer gets a clear glass every time. The latter ensures the condition, which has so carefully been developed in the beer during the maturation process, is maintained in the finished product and the beer has that satisfying sparkle in the glass and that refreshing and satisfying mouth-feel the customer is looking for. 

Conditioning tanks

Both these processes take us away from the concept of cask-conditioned beer so, as this is the main subject of this post, let us return to the British Isles where the old traditional methods lingered, and indeed thrived.  Despite moves towards filtration and pressurised dispense across Europe, Britain in the 19^th Century was in no mood to take lessons from its continental neighbours. Here cask-conditioning remained the main way in which beers were brought to maturation, prior to being served to the customer.

Cask-conditioning really came to the fore during the early years of the 20^th Century, when there was a shift away from the heavily-hopped and rather potent India Pale Ales, which had made the fortunes of many of the Burton brewers several decades earlier, towards lighter and more quaffable pale ales. This was understandable as, nice though they are, a heady IPA with an ABV of 7.0% plus, is not really a session beer and is not especially refreshing.

These weaker beers were initially known as “running ales”, because they were deliberately sent out by brewers in an immature state in order to finish their maturation, and hence develop condition, in the pub cellar. They became known as “bitter”, or “bitter ale”, and like continental Pilsner-style beers, looked attractive and sparkling in the glass. This made them an immediate hit with the drinking public. 

For certainly the first half of the 20^th Century, cask-conditioning was virtually universal in the UK, but the practice does suffer from a number of inherent defects, the chief one of which is the limited shelf-life of cask ale, once the cask is broached. This problem was exacerbated by the effects of two world wars which saw quite drastic cuts in the gravity of many beers (particularly during the Great War), due to the need to conserve ingredients during these times of national crisis. 

Weaker beers obviously don’t keep as well as stronger ones, and there was a further problem with cask beer in so much that it is quite easy to adulterate the contents. The disgusting practice of returning “slops” to a cask, (particularly the mild ale cask), carried out by quite a number of unscrupulous pub landlords, caused many drinkers to distrust draught beer, and switch to bottled instead. In fact there was a massive rise in sales of bottled beer, particularly after World War II, which took place at the expense of draught (cask) beer.

I won’t repeat the story of the rise of “keg” beer as the development of what effectively is bottled beer in a much larger container dispensed, continental-style, by CO2 gas, is well documented elsewhere. Whilst keg beers were embraced, certainly by many publicans for their ease of handling, and promoted by many brewers, because they ensured a consistent pint by reducing the chances of lazy or ignorant landlords spoiling the finished product, they were not universally welcomed by drinkers. Many felt that the filtration and pasteurisation processes necessary to ensure a stable product, significantly altered the taste of the beer, and the gas used for dispense, often accompanied by excessive cooling, had a further adverse effect on the beer.

Perfect combination

Customer dissatisfaction led to the emergence of consumer groups like the SPBW (Society for the Preservation of Beers from the Wood) and, of course, CAMRA. The success of CAMRA in particular, in promoting the undoubted merits of traditional draught beers, as opposed to heavily advertised national keg brands, led to a dramatic resurgence in the fortunes of cask-conditioned beer. This resurgence started off in quite a small during the late 1970’s, but really took off a decade later; so much so that sales of cask beer are still growing today. 

I suspect that a change occurred during the 1980’s, when brewers began to exercise a lot more care over their cask-conditioned beers than they had hitherto done. Whilst it once was considered normal practice to rack the beer straight into casks, virtually straight from the fermenting vessel, they now introduced an additional holding stage, whereby the “green” beer was allowed to condition, in bulk, in enclosed tanks at the brewery. Only then, after a sufficient time period had elapsed, was the beer run into casks.

Science would also have played a much greater role here, as brewers started to count and monitor the number of yeast cells present in the beer, again holding back racking until the count had fallen below a certain level. I suspect this process has been further refined, so that much of today’s cask-conditioned ale has a relatively low yeast count, with much of the conditioning having taken place in bulk. Casks racked in this fashion will drop bright fairly rapidly; often in a matter of hours, due to the low yeast counts in the beer delivered to the pub.

Cask beer has therefore become more consistent and far easier to handle, but like many beer drinkers, I feel it has lost something of its character along the way. Without that extra maturation taking place in the pub cellar, the beer is often served too young (green), and is missing some of the subtle nuances it once had. This is particularly true of many once revered beers which, having become victims of their own success and become far more widely available than they once were, now taste rather bland.

Isinglass finings

Before winding up this admittedly rather lengthy article, it is worth noting one cellar practice which has completely died out. These days it is universal for the isinglass finings, necessary to clarify the beer, to be added either just before the beer leaves the brewery, or at the end of the maturation phase when the beer is racked into casks. What many people don’t realise is it was once a quite common practice for finings to be added in the pub cellar, after the beer had left the brewery. This would have been in the days when many of the larger pubs, in particular, employed a “cellarman”, whose job was to look after the draught beer by bringing it into and then maintaining it in peak condition. 

I knew someone who had such a position, albeit in a part-time capacity. He worked for the Royal Mail in the Dartford area, but in order to supplement his postman’s salary helped out in a local pub at weekends and on the odd evening. He told me that certain beers, such as Bass and Worthington, were delivered un-fined and it was his job to add the finings prior to stillaging and venting the casks. This would have been during the 1960’s.

I didn’t know this chap especially well, but he was the father of one of my wife’s friends. He sadly passed away a few weeks ago, so the opportunity to question him further is now gone. It’s fascinating though such practices were still being carried out within living memory, and also proof of how much has changed when it comes to looking after cask-conditioned beer.