Whenever I'm out in a bar I always see bottles of ale or ale on a pump but I have never seen a bar that serves ale from a regular tap why is this ?
Is there a reason for this?
Collating Darwin and jalynn's answers and some experience running a real ale bar:
In the UK, real ales will always be served from a hand pump, as per the definition from CAMRA:
Real ale is a beer brewed from traditional ingredients (malted barley, hops water and yeast), matured by secondary fermentation in the container from which it is dispensed, and served without the use of extraneous carbon dioxide.
But you will always see Carlsberg, Budweiser, Heineken, Guinness, Stella etc pumped using CO2.
If you haven't seen them, it must be down to the pubs you frequent :-)