I pulled the cup at 30g which I usually do (mostly on sight but this time I wanted to use the scale/timer)
For the Tonino number, when one wants to be able to exactly compare with fellow roasters, one needs to be calibrated to each other's grind setting when preparing the test grinds. Having said that, of course T#110 always points at a fairly light roast, T#120-130 to filter roast, T#60-70 to very dark roasts that i would never drink etc.
I mostly roast to my Tonino #95, plus or minus 4 and then extract starting with 3-3.5 bar preinfusion.
On the light roast Ethiopians, I found 4.5 bar on a more coarse grind also worked very well but my girl friend prefers the 5-6 bar preinfusion and the grind as used in the video. At lower PI pressure, the very special and in my view fascinating taste of these honey processed Ethiopians are highlighted but i understand why for some, a little of that 'wildness' is already sufficient in the cup to start the day ;-)
Thanks for your response. I was curious because I have also been pulling a lightly roasted Ethiopian at the same dose and found it tasted better at 5 bar preinfusion. The roaster recommended 18g dose / 30 g yield, but I found I preferred a 36g yield.
The Tonino seems like an objective way to determine roast level, and thereby expedite and/or simplify dialing in a roast. Didn't realize that little bugger runs $600 USD, though!
as a rule of thumb i like to pull the cup when the lever arm reaches vertical; this willl almost entirely avoid the blond tail going into your cup if you have the correct pre-infusion set for the roast/dose/grind combination
with an organic product like coffee you are chasing a moving target
the londinium architecture now allows you to almost instantly shift the settings of the machine to track the ageing of your roast in a way that is intuitive and utilises a single parameter only (pre-infusion pressure) to control the other parameters (brew temperature, brew volume) whilst maintaining the equilibrium of the system (i.e. maintain thermal stability)
the other advantage of an almost instant response from the system to any change you make to the pre-infusion pressure is that if you dont get it quite right on the first attempt it doesnt matter, you just tweak it a bit more, or less and the system responds almost instantly again
sitting there for half an hour waiting for the group to change temperature gets old fast. that does not happen with the londinium architecture.
Thanks for your insight. It did not occur to me to reduce the preinfusion pressure as the coffee ages (I would've guessed to increase as it ages). Thanks for the pull-when-vertical rule of thumb. I'll keep an eye on my pulls and see if I'm close to that mark.
yes, that has been one of the lessons i have learnt since we developed the digital pre-infusion
that made it even more important to develop the wireless module as pulling off the side panel regularly is a pain
some customers have requested the ability to pre-infuse to pressure 'X' then for the pump not to come on again and an ultra long pre-infusion duration of up to 5 minutes
i am pleased to tell you that the wireless module supports this style
all you need to do is select the longest pump interval (2s) then select the pre infusion pressure you desire, then as soon as the pump turns off after you pull the lever down (indicating that the target pi has been achieved) you slide the target pi to zero, which ensures that the pump does not turn back on