Variable pre-infusion pressure works well on the L-R
Today the variable pre-infusion pressure on the Londinium L-R came in very handy.
I aim my roast to be consistently of about the same roast intensity, measured in a roast color acquired over a certain time. Mostly color Tonino #95 with a 15 minute roast.
With a new bean it takes some time to tweak the roast profile and with a Sumatra bean I roasted the first batch rather dark, Tonino #83 even. That's not exceptionally dark compared to many beans sold in shops, they are not oily for instance beyond a tiny spot here and there on a few beans. But these Indonesian semi-washed beans which tend to have lots of 'body' already behave like dark beans, with a faster flow.
Before, I would send these to a friend that I know who finds that really dark beans work best in her automatic coffee machine.
Now I tried them myself and I find it yields delicious spicy earthy coffee with lots of body even when using just the 15g VST basket instead of the 18g basket that I mostly clip into the portafilter.
This works so well thanks to the variable pre-infusion pressure.
I took off the lid of the L-R and turned the adjustment on the Ceme p-stat down (clockwise) so that the pressure is very low but pulling the lever stil activates the pump.
Result: a subtle delightful Sumatra in the cup with lots of body while not bringing too much of it.
Works fantastic as a cappuccino as well. I practically never froth milk but it was yummy.