Hi Experts,

I just recently bought the GS3 AV and I wonder which settings are used for the PreBrewing on the AV. The big difference is that the Pump will be used for PreInfusion which makes the normal suggested values useless (I read several threads that 5sec are recommended)

Question: What are the beste PreBrewing Settings. Here are the default settings:

PreBrew. ON sec Espresso: 0,6
PreBrew. ON sec 2 Espressos: 0,8
PreBrew. OFF sec Espresso: 1,8
PreBrew. OFF sec 2 Espressos: 2,4

Any suggestions?

Thanks
S.

Is everybody using the default values, or any optimization available? I feel that the timers for Pump ON are very short with the default values!?

Until I retrofitted line pressure preinfusion I kept it at 0. The giggler maintained the preinfusion. Turning the pump on may or may not cause the puck to break up and channel. If it doesn't why just not let it finish. If it does break up - turning it on and off won't put it back together again.

I still don't know why LM don't make this line lever preinfusion as an option. Just leave pump off and 3 way open. That is all. They say it is because most users use it as a pourover. Perhaps - but Nobody I know uses it as pourover.

I found that prebrewing/preinfusion on my volumetric GS/3 provided no value whatsoever over shots pulled with normal preinfusion.

Since my machine is plumbed in, I installed a motor switch so I could do line pressure preinfusion. That didn't have a whole lot of effect either.

Later I replaced the rotary pump with a variable-speed gear pump so I could do pressure-profiling. This, too, didn't have a dramatic effect, but at least it gave me more control over the preinfusion.

Then I lowered the line pressure to about 1.5 BAR so I could do very slow preinfusion. That, along with a very slow ramp to 9 BAR via the gear pump control, allows me to grind much, much finer and run shots much, much longer (sometimes as much as 90 seconds or more, including pre-infusion.) This allows me to pull very light roasted coffees that are otherwise difficult to extract. It's very similar to what you can do with the Slayer needle valve.

hmmmm.....

GS3 AV with the pump pre infusion do not satisfy me

I used now:

PreBrew. ON sec Espresso: 3
PreBrew. ON sec 2 Espressos: 1,5
PreBrew. OFF sec Espresso: 4
PreBrew. OFF sec 2 Espressos: 2

But no really difference in taste. Maybe I have to increase the value but I don't see the benefit, if the pump will run for 5-10 sec with 9bar and than make a pause for another 5-10 sec. I don't think they have implemented a proper PreInfusion into the AV version!?

The ruby gicleur is an excellent preinfusion. But it is limited in adjustability (you can replace it with a narrower or wider orifice gicleur).
So they added the pump based preinfusion which neither I disliked. It never helped a shot.

I did a similar setup that Dick had (I posted it a while ago at Mod La Marzocco GS3 to flow profile?) but without the gear pump. Just a TDR that delays the pump turn on and a flow limiter for when the pump is inactive. So now I can run a 30 second preinfusion for a 70 second run. Not that I do - but I can.