Well I certainly hope you didn't experience still beer when you were in the UK because a British beer should never be "still". The whole point of cask-conditioned beer is that it should have "condition" (ie fizz) as a result of secondary fermentation in the cask. If it doesn't have condition, then either the brewery has screwed up or more likely the pub.
Sure - it will have maybe half the fizz of a typical keg beer, but that's a world away from no fizz at all. Unfortunately there's a lot of badly kept cask beer out there, particularly in London, so it's perhaps not surprising that tourists think it should be "still" - but that's just faulty beer.
It matters for two reasons - the existence of condition proves that the beer is fresh and not stale, so the other components should be in good order, but also the subtle carbonation helps to push aroma molecules up into your nose. British beer is all about balance, malt, yeast, hops, water and CO2 all have a contribution to make to the whole without any one element being dominant. So they are certainly bitter - but they're not 100IBU alpha bombs.
If you're looking for a bitter recipe, here's
one off the top of my head that should get you in the right ballpark.
The only way to get even close to the effect of a sparkler from smallpack beer is the kind of nitrogen widget you get in cans of Guinness and Boddingtons. Don't even try at a homebrew level. In fact sparklers knock a lot of the condition out of the liquid, in order to create a creamy head - but that's a debate that rivals anything in the Middle East for intensity! Being a northerner I personally prefer beer with a sparkler - as long as the beer is designed to be served that way, and the pub is clued up enough to use the right size sparkler for the style and condition of the beer - there's a bit of an art to it.
At a homebrew level, the usual advice of 1.3-1.5 vol may be correct for keg, but it isn't quite right for bottles, I guess because of the headspace. I'd aim for 1.8vol or so in bottle. And do serve at the right temperature - straight out of the fridge will kill the flavour. 55F is ideal, but it's OK to serve at say 50F and let it warm up as you drink the pint and it comes up through the right temperature zone if you're in a warm room/climate.
I like a sick joke as much as the next man, but it's not your joke to make in public when there could be people reading (like me) who know schoolgirls whose classmates had legs amputated a year ago. Things are just a bit sensitive at the moment, with
the anniversary on Tuesday of that and 22 murders, round here it's a bigger thing than either a certain wedding or even the Cup Final.
