Basic pressure question

Matt Whyard

Hi,

I realise this is a very n00b question but I have never had a full-on espresso machine before so am a little inexperienced. I understand that true espresso requires something in the region of 8-12 bar pressure. I keep reading stuff around 1.5 bar with the Londinium. Does this mean that it doesn't get up to the same pressure as other machines? Or is this pressure referring to something else?

Thanks!

Reiss Gunson

hi matt

thank you for posting here

you are right, the pre-infusion phase (when you pull the lever down and the piston rises and lets water into the cylinder) occurs at boiler pressure which is around 1.3 bar

however, when you release the lever the pressure of the spring is initially 11bar on the water column, which diminishes to approx zero as the spring extends and the piston pushes the water through the coffee

apart from imparting the famous taste in the cup that only a lever machine with low pressure pre-infusion gives, it also means you do not have to backflush, unlike pump machines

if your concern is, will a LONDINIUM lever espresso machine give me 'proper' espresso, rest assured, the taste doesn't come any more authentic than from a spring lever espresso machine


kind regards


reiss

Unknown

Good explanation Reiss.

Matt, the pressure on the gauge that you see only refers to boiler pressure, not a pressure that is related to pressure in the puck generated by a pump machine. The pump in the L-I only fills the boiler.