if you mean weighing for every shot? Then it's impossible when busy, because the vast majority of customers care more that their coffee isn't horrible and it quickly rather than perfect and slowly, although I think Prufrock might. When tamping it is very easy to feel if there is less or more than their should be anyway. Timing should be done every time, some machines have timers built into each group so that's easy, but again, when you're making shot after shot it is easy to tell if one has come through too quick or slow, and not just from the time, the colour, how it sits in the cup and the crema also make it obvious.
If you're buying coffee in a shit place, expect it to be shit, simple.
if you mean weighing for every shot? Then it's impossible when busy, because the vast majority of customers care more that their coffee isn't horrible and it quickly rather than perfect and slowly, although I think Prufrock might. When tamping it is very easy to feel if there is less or more than their should be anyway. Timing should be done every time, some machines have timers built into each group so that's easy, but again, when you're making shot after shot it is easy to tell if one has come through too quick or slow, and not just from the time, the colour, how it sits in the cup and the crema also make it obvious.
If you're buying coffee in a shit place, expect it to be shit, simple.