Mr. X is a 30-something, educated, young male, originally from somewhere in Scotland, currently living and working in London. He is an entrepreneur, moderately successful, and comfortably middle class. He is single and lives alone. He has a cat.
Now since I'm not entirely sure when I'd like to set this story, I need to know the coffee stats for three periods of time: 1950-1955, 1975-1980, and 1990-1995.
I have found some information on coffee consumption today, such as adult males under 65 average ~13 cups per week while adult females of the same age average ~11 cups per week. But seeing as we're the Starbucks generation I really don't want to depend too much on those statistics. While it might be reasonable to assume something of a similar trend in London in the mid 90's, it was probably quite different in the immediate post-war years and the early 50's.
Wikipedia has a List of countries by coffee consumption per capita (which is cool to compare to the equivalent tea consumption article), but that's too high level. The most useful thing I could find was a sentence in the coffee culture article that said: "Consumption has also vastly increased in recent years in the traditionally tea drinking United Kingdom, but as of 2005 it was still below 5 kg per year."
So, to recap -- how likely would it be, given the time periods mentioned above, for the character to: A.) drink coffee at all, B.) be able to purchase said coffee with (relative) ease, C.) how much and how often would he drink? (eg. one cup after dinner; a cup in the morning; 12 oz of espresso every 30 minutes....)
And if all else fails, I suppose there's always tea....
Research done: googled "coffee consumption in the uk", "coffee consumption trends in the uk", and various combinations of 1950/1970/1990 with "coffee consumption" and "uk" ; also read all the wikipedia articles even vaguely related to coffee