I agree, you can use a timer to chase your own tail around the bathroom, but this may not prevent you from slipping on tiles! (bad analogy, I know - but hey, it's the best I could do at short notice) I reckon that the best indication of extraction time comes down to how well the coffee is pouring (Ideally, it should run with something resembling a mouse tail!), combined with actual taste! The extraction times will vary somewhat according to the time of day, amount of humidity in the air, age and type of beans you are using, the sharpness of you blades in the grinder, what sort of grinder you are using, what sort of espresso machine you are using, and the level of skill and expertise of the person making the coffee. Yes, I agree that timing is an important indication of how well the coffee is extracting, but that don't mead diddly-squatt if the resulting coffee tastes like *^$%@$.. The extraction time will also vary depending upon a single or a double shot, and even a 'slow' extraction time can sometimes be 'saved' by a short pour. I suggest that the cafe owner, first, knows what they are doing and what they are talking about (and if not, make every attempt to find out) and second, that they work closely with their coffee supplier to ensure that they are getting the maximum FLAVOUR possible (as opposed to extraction time), from their beans and equipment. Even if you own your own equipment, most roasters will, in my experience, be only to happy to wok with the cafe owner to ensure that their coffee is getting the full attention and proper respect it deserves. ACG
