HX vs. double boiler temperature stability - Page 3

[sversimo]

What is the swing? Is that why you're modifying it to be a DB?

The swing comes from how a HX machine behaves.

I can make a excellent first shot of espresso, but hitting the target temperature the second time is freaking hard!

Its also hard to target exact temperatures, 94C instead of 93C, on the first shot. The second is often way off. If I dont flush between shots, got a Mazzer mini E, the start temperature would be 5-6C too high.

[cannonfodder]

Ive been looking at the VDD DB machine. So, when brewing a shot, what does the PID show?

The water temperature at the point of the probe in the boiler, which will be different than the temperature in the the group head supply pipe, which will be different than the temperature in the group head which will be different than the temperature at the top of the puck, which will be different than the temperature at the bottom of the puck which will be different than.....

Water temperature is obsessed over because it is one of the objective variables that can be measured for an end product whose quality is a subjective subject. Which one is better, the one you enjoy using.