[Help] Profitec Pro 500 - low brew pressure

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lucade2210

#1: Post by lucade2210 »

Hey guys, newbie here

Just bought a new profitec pro 500 with a profitec m54 grinder. Been reading up on how everything works and practicing a lot to get everything right.

Unfortunately I feel like I've already run into a problem. My profitec pro 500 exhibits relatively low brewing pressure during extraction.

Timeline:
  • PID at 124C (255f)
  • Boiler pressure at 1.25 bar
  • M54 grinder set at 1.5 (almost the finest setting, turning finer gives lots of resistance)
  • Dual spout portafilter filled with 17g
  • Tamp relatively hard
  • Insert portafilter
  • Open pump
  • Brew pressure goes to 4 bar pretty much instantly, but stays there for the remainder of extraction. Never reaches 9 bar
  • After 27secs, around 50grams of extraction
  • Coffee tastes kinda meh, bit sour, no sweetness
I tested the machine with a backflush and I reached a perfect 9 bars, also the machine is brand new, so I don't expect any problems there. It's most certainly something I'm doing wrong, right? Do I set the grind even finer? Do I need to push the portafilter in there really hard? Anything else?

Bonus question: the lever has like two positions; 45 degrees and 90 degrees. Obviously 90 degrees activates the pump, but what does 45 degrees do? at 45 degrees nothing happens on my machine.

Tnx in advance,

greetings,

Luca

JRising
Team HB

#2: Post by JRising »

lucade2210 wrote: I tested the machine with a backflush and I reached a perfect 9 bars, also the machine is brand new, so I don't expect any problems there. It's most certainly something I'm doing wrong, right? Do I set the grind even finer? Do I need to push the portafilter in there really hard? Anything else?

Bonus question: the lever has like two positions; 45 degrees and 90 degrees. Obviously 90 degrees activates the pump, but what does 45 degrees do? at 45 degrees nothing happens on my machine.
Yes, the finer you grind and/or the more you dose, the more restriction to flow you will create and the higher the pressure drop will be across the coffee puck. Ie, the pressure difference between the water on top of your coffee-prep in the basket and the atmospheric pressure below it.

At just above the 45 degree point the drain valve will have closed and the brew valve will start to open. If the machine is plumbed in (And doesn't have an inlet valve preventing line-preinfusion) this will allow a slow pre-infusion at the 3.5 to 4.5 bar pressure of your plumbing. If the machine isn't plumbed in (or doesn't allow water through inlet when the pump isn't running) then it just depressurizes your brew circuit a bit because the brew valve will be opened, possibly dampening and/or steaming the coffee-prep a little bit. Not much advantage to it.