What is beer?
All beer is brewed from four ingredients – malted barley, hops, yeast and water – although other ingredients such as fruit, wheat and spices are sometimes used. The yeast turns sugars in the malt into alcohol and the hops provide the bitter flavours and flowery aroma.
The flavour of the beer depends on many things, including the types of malt and hops used, any other ingredients added and the yeast. That last factor is one of the most important and getting the yeast right is essential as each variety has its own distinctive effect on the beer.
So what is real ale?
In the early 1970s CAMRA coined the term ‘real ale’ to make it easy for people to differentiate between the bland processed beers being pushed by the big brewers and the traditional beers whose very existence was under threat.
Real ale is a natural product brewed using traditional ingredients and left to mature in the cask (container) from which it is served in the pub through a process called secondary fermentation.
Confusingly however, many pubs and brewers also call real ales cask beers, cask-conditioned ales or even real beer.
Why isn’t all beer real?
Real ale is a natural, living product. By its nature this means it has a limited shelf life and needs to be looked after with care in the pub cellar and kept at a certain temperature to enable it to mature and bring out its full flavours for the drinker to enjoy.
Brewery-conditioned beer has a longer shelf life as it is not a living product. Basically, after the beer has finished fermentation in the brewery and has been conditioned, it is chilled and filtered to remove all the yeast and then it is pasteurised to make it sterile. This is then put in a sealed container ready to be sent to the pub.
The problem is that removing the yeast and ‘killing off’ the product through pasteurisation also removes a great deal of the taste and aroma associated with real ale. Because there is no secondary fermentation occurring in the container in which is held, there is no natural carbonation of the beer so gas either carbon dioxide or a mixture of carbon dioxide and nitrogen has to be added to “fizz up” the beer.