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The Beer Cellar of a Public House

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A beer glass.

Although most adults have often visited a public house, very few are actually aware of just how the drink they are served with gets into their glasses. This Entry is aimed at being a basic introduction into the sometimes arcane world of the beer cellar and the cellarman - two of the most important factors in the production of 'a decent pint.'

The Cellarman

At one time a full-time position in most of the larger public houses and licensed premises throughout England, nowadays the role of cellarman is usually just part of the responsibilities of either the publican him- or herself, or a head barman/bar manager. The basic responsibilites of the post are to ensure a continuous supply of high-quality beer to the establishment's bars.

The Beer Cellar

In an ideal world, the beer cellar should be situated directly below the bar - thus ensuring the shortest possible distance between the barrels of beer and the beer taps on the bar. The cellar itself should be kept at a temperature of 12°C/53°F1. Modern cellars are generally fitted with a cooling system, operating on the lines of an air-conditioning plant, ensuring the temperature remains relatively constant. It goes without saying of course that the cellar must fulfil modern health and safety regulations - it must have adequate drainage, be easy to clean, have a suitable water supply and lighting, etc. The cellar should also be large enough to hold at least ten days' supply of beer.

Types of Beer

As far as a cellarman is concerned there are only two types of beer: not lager/bitter/stout/etc, but 'keg' and 'cask' beers.

Keg Beers

In a modern bar this term can be taken to cover all lagers, stouts, draught ciders and those bitters not served using a traditional 'beer engine'. All of these drinks have several common points: they are all pasteurised, pre-filtered and served chilled using a pressurised gas system to both push the beer through the pipes to the bar and to produce the bubbles.

The barrels themselves are generally of stainless steel construction and hold either 5.5 gallons (25 litres) for low-volume sale beers, 11 gallons (50 litres) as a standard size or 22 gallons (100 litres) for high-volume sales in large pubs.

The mechanics behind the serving of a keg beer are as follows:

  • The barrels are positioned vertically - each barrel is hermetically closed and pressurised in the brewery prior to delivery2.
  • Running down the centre of the barrel is a long 'spline' - basically a hollow metal tube through which the beer is drawn up into the pipes connecting it to the bar.
  • The barrel is also connected to a high-pressure gas bottle (via several reducing valves). As previously stated, this gas is used to propel the beer up through the pipework to the bar and also, dependant on the type of gas used, produces the bubbles (in ciders and lagers).
  • On opening the 'tap' in the bar, the beer then flows up through the lines, is chilled down to 5 or 6°C en route and is served.

The general cellar set-up for the serving of keg beers varies from pub to pub and is dependent on the number of different beers sold and their types. Generally however, each barrel has a single connector on its top, which connects the barrel to both the appropriate tap (or taps) on the bar and to a pressurised gas 'ring main' running around the cellar. Each and every brewery has their own unique type of coupling to stop publicans inadvertently3 connecting another brewery's beer to a particular tap in the bar.

There are two methods of chilling the beer en route, these are described in detail in the following paragraph, but both involve passing the beer through copper piping immersed in a bath of chilled water.

Keg Beer-chilling Equipment

Method One - Behind-bar Coolers

This method is used in smaller bars (or those serving a small number of beers).

The beer is fed up to the bar area through insulated plastic tubing and through a small chilling device4 situated under the bar counter itself. The chilling device is simply a metal box containing a fridge compressor system used to chill a tank of water. Up to two beer lines can be connected to each cooler and each beer runs through a copper 'serpentine' immersed in the water bath - beers can be served at differing temperatures by the simple method of varying the length of the copper tubing immersed in the bath. The beer runs from the cooler directly to the tap, a matter of a few inches of pipe, and should thus be at the perfect temperature for service.

The advantage of this system is its simplicity, the major disadvantage for larger bars is that multiple coolers behind the bar take up a great deal of space and kick out a great deal of heat. In addition the system requires separate pipes to be run up from each barrel to each tap. Thus, the second method was developed for larger bars.

Method Two - The Central Cooler/Python System

A single, much larger, cooler is situated in the beer cellar itself. The pipes from each individual barrel are then run directly into the cooler and through their own individual copper coils5.

From there, a 'python' is run up to the bar itself; a python is a pre-bundled set of insulated plastic tubes, each one individually colour-coded to ensure identification. Pythons can contain eight, 16 or even 32 separate beer lines in a single bundle. In addition to the individual beer lines, chilled water is pumped from the cooler through the python in a closed circuit system with its own larger diameter pipes.

Behind the bar itself, the taps are connected by simply cutting into the outer insulation of the python, identifying the correctly coloured pipe and connecting it to the appropriate tap.

The major advantage of this system is the simplicity, one single pipe to feed through from the cellar to the bar and a single cooler. The disadvantage is the equipment cost involved - a bill usually paid by the breweries. Thus, this method is generally reserved for high volume sales establishments.

Keg Beer Gas Types

There are two different gases used in the service of keg beers:

Carbon Dioxide

Carbon dioxide is used in the service of lagers, 'fizzy' bitters and ciders. The major reason for this is that carbon dioxide is absorbed by water when under pressure. Thus, when the pressure is released - that is, when the beer is served, the carbon dioxide is released from the liquid, creating the bubbles found in such drinks.

Mixed Gas

This is a mixture of carbon dioxide (30%) and Nitrogen (70%) used in the service of stouts and 'draughtflow' bitters. The major difference is that since nitrogen is much less readily absorbed into the liquid then the resulting beer is much less 'fizzy' and tends to have a creamier, denser head.

Cask-conditioned Beers (Real Ales)

In the 'good old days' the only beers available in the UK were cask-conditioned. These beers, although lauded by organisations such as CAMRA (The Campaign for Real Ales) do require much more work on the part of the cellarman and this work (or lack of it in some cases) plays in important role in the quality of the beer itself.

The beer itself is delivered to the pub in a partially-finished condition and once placed in the cellar undergoes a secondary fermentation process - this breathes life into an otherwise 'immature' drink.

The barrels used are unpressurised and must be placed in a horizontal position prior to use. The end of the barrel is fitted with a simple wooden (or plastic) bung, and a second bung is located midway along the side of the barrel. The days of wooden barrels have unfortunately almost entirely gone and nowadays, for economic reasons, most real ale casks are stainless steel.

The beer is served through muscle-power alone, with no pressurised gas system6 and is not run through a cooler. Each barrel is connected directly to an insulated plastic pipe running straight from the cellar to a manual 'beer engine'.

The Beer Engine

The 'beer engine' or 'hand pull' is the traditional method of serving real ale. The device is simply a lever, fixed to the bar, connected to a a cylinder and piston (usually of 1/2 pint capacity) directly below the bar counter. Pulling on the lever pushes beer out of the cylinder into the glass, whilst pushing back on the lever, through the technical masterpiece of a simple non-return valve, draws more beer up through the pipes and refills the cylinder.

Although the cylinder is generally insulated, this system does have the major drawback that if a beer is not served for a length of time (overnight) then the first half pint of beer drawn from the pump does tend to be too warm - and in most good pubs the barman will discard this half pint.

Preparing a 'Real Ale' for Service

The most complicated part of a cellarman's job - if he gets it wrong, or neglects his duties, then a pub can rapidly lose clientele.

From the moment of delivery until a barrel is emptied, constant attention must be paid to a barrel of real ale and various steps are requisite in the serving of 'a decent pint.'

  • On delivery - the barrel must be immediately placed in a horizontal position on a 'stillage' - generally a wooden rack, designed specifically to hold the barrel securely in a virtually horizontal position (usually slightly angled towards the front of the barrel).

    This must be done immediately as there is still a great deal of sediment suspended in the beer. Every time the barrel is agitated the sediment takes longer and longer to settle - thus, if a barrel is left any length of time before being prepared for service, the additional movement of placing the barrel on the stillage means that it will take much longer to 'clear' and be ready to serve.

  • Immediately7 after the barrel is placed on the stillage it must be 'vented.' This process involves piercing a hole in the bung, now on the upper surface of the barrel, allowing air to enter the barrel and starting the process of secondary fermentation.

    To stop foreign bodies (such as insects) entering the barrel the hole is then 'stopped' using a porous, softwood 'peg'.

  • 48 hours later8 a steel or brass tap is driven into the bung on the end of the barrel.

    The reason behind the timing is simply that the sediment in the beer has had time to fall to the bottom of the barrel and is therefore less likely to fall onto the tap within the barrel and thus be drawn up into a glass. The 24 hour delay between 'tapping' and service is to ensure that any sediment disturbed by the process has time to re-settle.

  • Prior to service - The cellarman should draw off a quantity of beer from the tap in the barrel to ensure its clarity - if it isn't clear it shouldn't be served!

  • If a barrel has cleared (thus is ready to serve) but is not yet required - then the softwood peg should be removed and replaced by a non-porous, hardwood peg - thus sealing the barrel and slowing the ageing process.
  • Prior to each service period in the bar the wooden peg should be removed from the barrel - otherwise the action of the beer engine builds up a partial vacuum in the barrel making it virtually impossible to pull a pint. However, the peg must be replaced at the end of each service period (when the bar closes for the night).

If kept correctly, a barrel of real ale should easily last from ten days to a fortnight once delivered - however, once it has been connected up and is being served it should be drained within three days.

To avoid wastage as the level of beer in the barrel falls, the barrel may be gently tilted forwards and held in place by wooden chocks - thus reducing the amount of beer wasted in the barrel9.

'Cleaning the Lines'

Probably one of the most onerous parts of the cellarman's job - generally involving early morning starts the day after a late night at work.

The pipes, running between the cellar and the bar, must be cleaned out on a regular basis. For pasteurised keg beers this is generally done weekly, however, for unpasteurised cask ales - with their high yeast and sediment content, this should be done at least twice-weekly.

The process involves removing the pipes from the barrels. Keg lines are connected to a pressurised water barrel and cask lines dropped into a stainless steel bucket of water.

Water is then drawn through all the lines to remove any beer. It is at this stage that certain cellarmen keep hold of the beer drawn off and transfer it back into the barrel from whence it came. However, this process is frowned upon by virtually every single brewery in existence, in addition to being a mortal sin as far as CAMRA is concerned (and for pressurised keg beers the process is semi-suicidal due to the pressure in the barrels!)

Once water has been drawn through the lines, the cellarman once again descends into the cellar and replaces the water in the buckets and pressurised containers with a solution of 'line cleaner'10 and water.

He then draws this colourless liquid through each line until the line is filled with the solution. The easiest way of determining whether water or cleaning fluid is coming out of a tap being to test it with the fluid having a slightly 'oily' feel to it.

The lines are then left to soak for ten to 15 minutes. More fluid is then drawn through11.

The lines are left a further 15 to 20 minutes. Then, the cleaning fluid containers are once again replaced by fresh water containers and each and every line is rinsed through with copious quantities of fresh water12 before the barrels are reattached to their respective lines.

Although the physical effort involved in cleaning keg lines is minimal (with the exception of the repeated descents into the cellar and the disconnection and reconnection of the various lines), the muscle power required to pull several gallons of liquid through each and every beer engine in a pub (that may have a dozen or so real ales), makes this task one of the least popular in a cellarman's diary. However, shirking these fairly simple chores is one of the simplest and quickest ways known by any cellarman of emptying a pub and ruining an establishment's reputation!

Barrel Sizes

Technically speaking, very few pubs actually serve beer in 'barrels' as each particular size of container has its own specific name - and as a true beer barrel weighs something in the region of 190 to 200 kg, then health and safety regulations rule it to be inappropriate for most establishments.

The traditional appellations and sizes of 'beer-containing vessels' are as follows...

NameImperial VolumeMetric Volume
Firkin9 gallons*41 litres
Kilderkin18 gallons*81 litres
Barrel36 gallons163 litres
Hogshead54 gallons245 litres

* NB: Certain breweries have now gone metric and have changed the sizes of their 'firkins' to 11 gallons (50 litres) and their 'kilderkins' to 22 gallons (100 litres).

Footing the bill - who pays for all the equipment?

Although it is possible for a pub to purchase all the equipment used in a beer cellar it is very rare that they actually do so. In general, the equipment is supplied and fitted by the the principal supplier of beer to the establishment.

If a pub wants (and is legally entitled) to sell beer from more than one brewery then the equipment supplier will generally fit all the equipment needed and then 'lease' lines to the other breweries - the administrative work being the responsibility of the brewery itself and not the publican. If the balance of trade shifts from one brewery to another then one of two things may happen. Either the new principal supplier will purchase the cellar equipment from the outgoing supplier, or, if the equipment is too old, the new supplier will ask the previous one to remove their old equipment and will replace it with newer equipment.

Each individual case depends not only on the age of the equipment involved but also the buying-power of the publican. In a highly competitive environment the owner of a large 'free-house'13 is in the perfect situation. The client really is always right, and can have brewery reps falling at his feet to give him the best possible deal.

However, and finally, one should always spare a thought for the poor tenant of a 'tied-house'14. A tied house can sometimes end up paying more than twice what a free-house pays for the same quantity of beer!

1To all those of 'foreign' extraction who assume the British like warm beer - it's not true! A perfect pint of real ale should be served at cellar temperature - 12°C - not at room temperature2Thus the barrel cannot be refilled in the pub and no cellarman in his or her right mind would risk attempting to open a keg in order to re-fill it himself - the effects of an 80cm long, 1cm diameter steel tube, topped by 1kg of pressure valve, being propelled violently skyward by the pressure in a barrel tends to put an end to this sort of practice rather abruptly!3Or for reasons of profit!4Approximately 80cm wide, 40cm tall and 40cm deep.5The physical cooling method is identical to that of the smaller coolers - copper piping in a chilled water bath.6Notwithstanding this, some pubs do use a low-pressure CO2 system to create a 'blanket' of gas over the surface of the beer, thus extending its life during service.7At least three days prior to service.8Minimum of 24 hours prior to service9Waste beer is known in the trade as 'ullage'.10An highly corrosive caustic soda-type chemical11If the lines between the cellar and bar contain two pints of liquid then at least two pints should be drawn through.12At least four times the quantity of water as the volume of each line.13A pub or hotel not financially tied to a single brewery.14A pub or hotel contractually obliged to use a single supplier - usually as part of a tenancy agreement.

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