With the Schlafly Cod and Cask Festival quickly approaching I thought it would be fitting to re-post this comment made by Dan Kopman in the Casks! Casks! Casks! post.  image080.jpgIt’s an extremely informative look at cask beer not only in the UK but also for Schlafly.  Enjoy:

Not to show my age too much but the term real ale came about in the 1970’s in the UK with the founding of Camra, The Campaign for Real Ale. Prior to the 70’s almost all beer sold in Britain was cask conditioned ale. Before we go into production methods for cask conditioned beers the history, abbreviated for simplicity is as follows:

Pre-1970’s almost all beer sold in the UK is cask conditioned real ale. In the 1970’s lager beers like Heineken and Carlsberg begin to appear from the continent in greater quantities. These beers are “brewery conditioned” in that all fermentation and conditioning happens in tanks prior to packaging. Therefore they are stable and do not require careful cellaring and attention. Note that “cellars” in US pubs are also set up for dispense of “brewery conditioned” beers that are stable and are dispensed in a fully enclosed system with CO2 or a mix of CO2 and Nitrogen. The major UK brewers took notice of this and thought hey, we can save on labor and losses and move ales into kegs. Thus were born brands like Watney’s Red Barrel, Allied’s Double Diamond etc. The small regional brewers, like Young’s were I found myself in 1983 and Fuller’s did not have the equipment to produce “keg” beers. And, many traditionalist consumers found these new “keg” beers as a “sell-out” to the Continentals. Thus, folks like Michale Hardman who worked at Young’s and others gave birth to the Campaign for Real Ale.

Then and today cask-conditioned beers are produced by two distinct methods. The “old fashioned” way is in an open fermenter. Wort goes in, yeast is pitched and is “skimmed” off the top at high fermentation. At then end of primary fermentation, say 3 to 5 days, the beer is moved to a racking tank and is then “racked” into casks. At the time of “racking” or filling finings are added. No additional sugar or yeast is added as both are still present. The casks are then stored in the brewery for say 5 more days while the beer in the cask continues to ferment or “condition”. This last fermentation is used to build natural CO2 in the beer. The cask is ready to be sent to the pub. This was the method used at Young’s until the Brewery closed in 2007.

The other method, used by Fuller’s and many others uses unitank or enclosed fermenters similar to what we have. The wort and yeast go in but the yeast is not harvested off at high fermentation. After primary fermentation, the 3 to 5 days, the beer is put through a centrifuge filtration system and the bright beer goes into a racking tank free of yeast. In the racking tank, fresh yeast and if desired some additional sugar is added. Then the beer is racked into casks with finings added and stored in the brewery for another 5 days to go through the secondary fermentation or conditioning.

Remember the finings and note that a non-bright pint is a “bad pint” in the UK. The finings carry an opposite charge to yeast. Once the cask is in the cellar and in a position in which it will stay through dispense the finings bind with the remaining yeast in the cask and the two combined settle to the bottom of the cask above dispense point.

So this is the production of cask-conditioned ale. Beyond the production the other principal aspect of real ale is dispense without the “assistance” of any CO2 or nitrogen. This means that as the cask empties the space in the cask is replaced with air. Air is bad and this is why a cask on dispense has a bout a 2 to 3 day life. Some brewers in the UK will use “cask breathers” a little gizmo that pushes a small amount of CO2 into the cask in place of air. Camra has been debating the merits of these gizmos for years and if you think US Beer Geeks get into crazy debates don’t get started with Camra folks about cask breathers!

So to clarify what both Augie and Brennan said earlier, we currently employ a hybrid of the two methods. We “take” our cask ale off of a tank of beer in which most of the beer will be “kegged”. We presently do not produce 15 bbls of real ale. This would be about 36 casks and this will bring me back to the photo of casks that was taken prior to shipment this week in a container with our 2008 UK and European hops. So we take beer off the sample point at that 5 day point where the primary fermentation is complete and yeast and sugar still remain. We then simply bung the cask and store it to allow the additional fermentation and conditioning to happen. So the beer is cask conditioned. If we take it too late then we don’t get enough natural carbonation and we can get very flat cask ale on tap. If we take it too early the opposite. Then we dispense without CO2 or nitrogen – no cask breather. We do not add finings as I seem to be the only consumer of cask ale that is still hung up on a “bright pint”. We do not add any extra sugar to the cask or yeast. Recall I came from Young’s not Fuller’s and the head brewer at Young’s thought that adding more sugar was a “dirty habit” that he had seen in some “crazy, dirty Belgian breweries” to produce bottle conditioned beers – sounds like Cantillion to me! Remember 1980’s.

The confusion for Augie here is what is considered “secondary fermentation”. Is this fermentation to produce more alcohol and flavor or simply to produce the CO2, the conditioning in the beer. If you simply want the latter you do not have to add more sugar and yeast. You can call this the end of primary fermentation in the cask or a secondary fermentation in the cask. It is the same thing; it is what makes cask-conditioned beer or real ale as defined by Camra.

Now back to the 36 casks en-route. Since 1991 it has been a goal of mine to make complete batches of Schlafly Pale Ale (and now Brennan and Drew’s goal of complete batches of Schlafly Dry Hop APA) for cask. We will be able to treat the entire 15bbl tank at the Schlafly Tap Room brewery for cask. We will go through the primary fermentation and like at Fuller’s after 3 to 5 days we will move the beer into a “racking tank” then we can argue amongst ourselves if we want or need to add any additional sugar to get more or less carbonation or filter and re-seed yeast and we can keep arguing about finings. Then the casks will be stored here for what we can call additional fermentation for conditioning. At this point we will have 36 casks and these will go forth and find homes on bars throughout our selling area for “cask ale nights”. More details to follow on this program but in the meantime if you are a bar owner /buyer and are interested in Schlafly Cask Ale, let us know.

Happy Cask Conditioning.