This is an addendum to my previous two posts on the etymology of ale. In that text, what I mentioned as the modern definition of ale is something differentiated from lager based on fermentation conditions. After I finished writing I realized that I've had many conversations with people in the UK about ale and lager, and the colloquial meaning of ale is actually something quite different.
From my experience (which I admit is relatively limited), almost all beer drinkers in the UK understand that beer served on cask is an ale while beer served pressurized out of a keg is lager. This understanding pervades publicans, barmen, and casual drinkers alike. I've recently made a point of asking such people what they think the difference is between ale and lager and I almost invariably get an answer along the lines of, "ale comes from a cask, while lager comes from a keg". They may also add something about the flavor differences but, by and large, I do not get answers relating to the differing fermentation conditions that create ales and lagers.
At first I was inclined to frustration that nobody understood what the technical differences are between ale and lager, but then Dan Fox from The Bull very much put me in my place. I asked the same question of him and we talked it over for a bit (mind Dan has a much more extensive understanding of beer styles than I do). He eventually said to me something along the lines of, "Who really cares what the different fermentation conditions are between ale and lager? Behind the bar if somebody asks about a beer, you won't describe the technical bullshit, you will tell them how it tastes and how it will be served." (this is not an exact quote, but you get the picture) He was absolutely right. If you are describing an ale in the UK, you will say that it comes from a cask at cellar temperature with lower carbonation levels than something coming out of a keg. Unless you are talking to somebody with a keen interest in beer beyond just drinking it, top/bottom fermentation probably should not come into the conversation.
Yet, I still believe this understanding of ale may be contributing to the lack of kegged ale in the UK. I have found that there are two distinct kinds of drinkers; those who prefer ale (since this is the UK we are talking almost exclusively Cask Ale) and those who prefer lager, with relatively little overlap. It is my notion that the flavors of kegged ales probably would not appeal to lager drinkers and ale drinkers would not drink kegged ales because they perceive them as being lagers. As a result, there is a distinct dichodomy between Real Ale and lager with not a whole lot in between.
Of course there are exceptions to the rule. Sierra Nevada Pale Ale has made some headway here and more and more bottled ales from the States are showing up in the UK in bars and on market shelves. There are even some UK breweries making kegged ale, notably Meantime Brewing (however, the last time I asked a barman about a Meantime ale he thought it was a lager...)
Either way, I have clearly found out that ale means something different to the average person, and only the worst of beer snobs would have a problem with that. All I can hope is that eventually kegged ales will catch on and add even more creativity to an already thriving craft beer landscape.