Pump times and caffeine content

[Fallingwater]

In time I have learned to enjoy the taste of good coffee, but I still occasionally need it purely to keep my attention high. For those instances I have some 100% robusta that doesn't taste too good but is higher in caffeine content than your average robusta/arabica mix (and doesn't require me to hunt expensive super-caffeinated beverages online).

So, the question: do I get more caffeine by running my espresso machine's pump longer? I'm aware this results in a less concentrated brew and a fairly unpleasant, watered-down taste that vaguely resembles coffee; however, logic dictates that because more hot water is in contact with the grounds for a longer time, more caffeine should be extracted and end up in the cup - so even though the resulting pseudo-coffee itself is less concentrated I should get more, uh, wake-up-ness from it. Considering that in those must-stay-awake-NOW instances taste is entirely irrelevant, is this a good method to get the most caffeine out of your grounds?

 

[CCafe]

The amount you will extract via running more water through the grinds will be negligible at best. The problem is in order to find out whether your right or wrong you would need to have equipment able to measure the amount of caffeine in your shot. Then compare that to shots with more water content.

 

[shadow745]

I say mix robusta with arabica (maybe 50/50), grind finer and pull 1-1.5 oz. ristrettos in 45 seconds to 1 minute. I firmly believe slower flow = more flavor/solubles extracted. End result... intense, great flavor and maximum caffeine.