Ha, I forgot all about Shaq's little song. Its not the fact that its cold that makes it taste bad, but you can see the shot of espresso break down in a matter of seconds. Back in the day, Starbucks would repull the shot for you if it sat on the counter for 15 or 30 seconds. If you get a shot in a clear shot glass, it'll go from 3 layers, with the crema on top to pure black. But, if you're really drinking 6 shots in the same sitting, I'm guessing you're used to the bitterness since it'd be impossible to get them all pulled simultaneously, so it may not taste all that bad to you.