When to start timing shots from naked portafilter?

[jeffg]

I try to avoid living by the clock but it does help me as a general guide to go by. I am just wondering when is the correct moment to start timing from the naked pf? Do you start at the first sign of coffee appearing or the moment the coffee first hits the glass or the moment the first cohesive stream hits the glass? And I am assuming that from whichever start time is considered the right time you are looking for 20-30seconds from that point? Does the pre-infusion affect this judgement as well? I know some start timing when they flip the lever but that doesn't make sense to me, it seems to be consistent the start time should be some point where the coffee is visible? There is probably no single answer to these questions but thanks anyways!

[Rainman]

I think you hit the nail on the head, being a "general rule" and not something to live or die by. When I do use a timer (usually when figuring out something new, whether it be a new bean or grind setting), I'll hit the button the same time I throw the lever. I know I like to see around 5-6 seconds before I see the first drips hit the cup, and around 25-30 seconds for the whole double shot. I sometimes go longer, but rarely go shorter than that.

Ray

[HB]

Bottomless extractions appear to start sooner, beading around six seconds, but overall time is the same as spouted pours: Pump on to onset of blonding. A good starting point is 20-30 seconds for doubles and another 5-10 seconds for ristrettos (see Al's Rule for more details).