JohnB. wrote:200*F boiler temp or is that measured on the group surface?
Heh, well as you know, John, it's a slightly inexact science with a Bosco.
With how my pressurestat is set, the boiler lazily oscillates between 1.2- 1.3 bar. The kitchen at daybreak here is still on the quite cool side, so in that first chilly hour, I've found goosing the temp via letting off a bit of steam such that the boiler will reheat towards 1.4 bar, will provide a temperature that I estimate at close to 198 F in the basket, based on taste. Later on, when the group hasn't been used for a while, just a short flush to bring the grouphead up to temp just before I commence my grind/tamp routine works well.
I honestly haven't felt a compulsion to instrument the Bosco -- even with temp strips -- since, over time, I seem to have developed a Spidey sense of what it's doing, particularly in relation to coffees I've come to know pretty well. I focus on getting the dose, grind, and preinfusion right, and then I let the Bosco just do its uncanny magic dribbling exquisite black honey into the cup.