Cask Conditioned Real Ale, Explained

It is pretty fun reading all the new, and different definitions of cask conditioned, or "real ale" in the media surrounding this event.  Fun, as in most of them are not quite right.

Like many traditional food stuffs, this is about a traditional method of preparing, in this case, a libation, that was born of necessity in times when there was little or no refrigeration, and the science behind fermentation was not well understood.  Beer was made in a brewery, but because it had to be kept fresh in order to drink, it was packaged while it was still fermenting (barely) which would keep it preserved under a blanket of CO2 given off by the yeast, in the latter stages of fermentation.

The keg (or cask) was delivered to a pub where the publican then took over responsibility for overseeing the completion of the fermentation, and waited for yeast and other suspended solids to settle out.  The artistry related to this role was almost lost, but has been revived in much the same way as we now have traditional breads, charcuterie and cheeses becoming available.  Some publicans would add more fermentable sugars to raise the alcohol, others would add hops for flavour, and to extend shelf life.  They would also often add finings to the beer, powders, or liquids that settle through the liquid, collecting protein and yeast solids as they settle, to help it clear, such that it would look better in a clear glass. It is these additions that can negate a beer's status as being vegan, as they often are made from animal proteins.

Nowadays, many people are further changing the beer by adding non-traditional, but usually fun ingredients to the cask.  The process is traditional, some of the things being added by the publican, or even by the brewer prior to delivery, may not be.  That, however has nothing to do with whether the beer (which is almost always an ale) is a "real ale".  To meet that test, it has to be still "alive", that is, the yeast has not been filtered out, removed, or killed off.  Most would be dormant, in the settled solids in the heel of the cask, meaning that you don't want to have to move it from the cellar until it's done, or you'll be serving cloudy beer.

Incidentally, this is also the source of the term cellar temperature - the temperature this beer was served at because no refrigeration was available.  Ice cold beer is usually too cold to taste its goodness anyway.  British ale is not served "warm".  It's served at about 12-14 C (54-57 F) and that is what most real stone or earthen cellars range in temperature if they are not left open to the summer heat.

Once tapped, kegs of beer are generally good for 3 to 5 days, after which the air that enters the keg to replace the volume of beer brings spoilage mechanisms with it, creating a distinct sour taste that most people find objectionable.  This temporary, naturally regulated window of drinkability is one of the charms of "real ale", but modern times have seen the amount and cost of the extra work required to create such a short window of opportunity, cause real ale to become a speciality item, often reserved for festivals, rather than a day to day libation.

Beer aficionados (geeks) welcome more of this style of service, recognizing the amount of work involved, and, perhaps more important, the cooperation and coordination required between brewery and publican in eventually getting drinkable beer to the glass.  It is not easy.

Well, it's easy to drink.