Well - too much time and no working PC in the workplace means I have time to start experimenting.
This week I have been measuring the effects of the dry weight of the puck on extraction time.
I expected more coffee to equal a greater extraction length. This was not the case. There seemed to be no correlation between the two. Worried about my tamp I started using some bathroom scales to make that more constant. Still no correlation. I am guessing that heat plays a bigger part than I thought.
I've also found that my manual dosing gives a basket of 16.8g with a variance of about 0.15g
I would put the figures up but they are really boring. What do you guys reckon?