Optimum shot weight for La Pav Pro
My previous experience from a Silvia says that when you get water on top of the spent shot, you probably haven't dosed enough, and when you can't close the portafilter, you've got too much. Then you adjust the grind to get the flow right.
It's all different with the La Pavoni. Because it dispenses a fixed amount of water you never end up with water on top of the shot. I've tried weights from 13g to 19g and adjusted the grind to make each of them flow properly, and I can get a good espresso across the range. My question is: is there an optimum weight, or technique?