It’s a common misconception that we Brits tend to drink our beers warm.
I should like to set the record straight, ‘warm beer’ does NOT refer to the temperature the beer is served at, more the fermentation process that is used for traditional British ales.
British and European Ales tend to be ‘top fermented’ which means that the yeast acts on the surface of the beer, forming a large foamy head. These fermentations tend to take place at about 65 degrees Fahrenheit (18 celcius). Bottom fermented ‘lager’ type beers ferment at lower temperatures, about 45 degrees Fahrenheit but can mature for much longer. Hence the storage or ‘lagering’ process (lager incidentally comes from the same root as ‘larder’ – a food store).
Here in the UK commercial lagers are stored for about six weeks in massive tanks (over the yeast), but can be stored for much longer. The ‘Samischlaus’ beer (brewed by Hurlimann of Zurich until 1996 – now brewed in Austria) was brewed every year on December 7th, then ‘lagered’ until the following year before bottling. Samischlaus comes in at a whopping 14.7% ABV so approach it with caution.
I digress, let’s simplify things and say for now at least, if it’s top fermented it’s an Ale, if it’s bottom fermented it’s a Lager.
It should also be borne in mind that Ales are still very much alive, and will turn sour rapidly if not kept properly. A well kept Cask Ale should last a week or two if kept properly. After being stored (lagered) for 6 weeks or more Lagers are usually filtered and pasteurised before being transferred into either kegs or bottles – and will ‘keep’ much longer.
One of the characteristics of Ales is that they tend to be darker and more aromatic than Lagers, and those aromas are better expressed about the temperature they were brewed – which is room temperature. Similarly Lagers are crisper and more refreshing and benefit from being served chilled.
Here in the UK the major brewers introduced a ‘Cask Marque’ standard, which requires (amongst other things) that the cellar temperature should be kept at around 55 Fahrenheit (13 Celsius) while Wetherspoons (Britain’s biggest pub chain) displays the temperature of its chilled pipes for lagers, usually about 2 Celsius (about 36 Fahrenheit). There has been a trend in recent years to serve Guinness ice cold, but in my mind that just kills the flavour.
So, if it’s a dark aromatic ale, such as an English Bitter, then it’s served at room temperature or thereabouts to savour its rich hoppy aroma; if it’s a crisp Pilsner style Lager, then just chill!