pizzaman383 wrote:Try doing some experimentation to see if you can taste the difference between the various cooling methods. I suspect that the cooling method won't impact the taste as long as there is no difference in the total dilution. But the results of comparison is what will answer your questions.

I was always under the impression that quickly cooling espresso changed the taste noticeably. I remember reading about cafes that would refuse to pull espresso over ice because they didn't like the way it tasted (and also probably that people would use it to make cheap lattes with the free milk). Also one of my favorite drinks is the shakerato, espresso shaken vigorously with ice and simple syrup, and at least in my experience the espresso comes out tasting much more acidic than espresso that's just been cooled slowly.

Although I've never done a blind taste test comparing espresso cooled at different rates. It could be the dilution is causing a big change as well? Maybe I'll try a test this weekend

BaristaBob wrote:I agree with the ease of the above approach, but wonder what effect shock cooling has on espresso.

It'll take 5 minutes to find out - just pull a shot into a cold temp-safe shot glass or pitcher, put it back in the freezer for a few minutes, then drink it. The idea of an espresso martini doesn't excite me, but the spirit of adventure does. I may try it myself after dinner tonight.