trihard's question -
Good info! I am curious...with Erik's Thermometer, are you able to tell when your machine is sufficiently warmed up? I thought these machines needed more like 30-40 minutes to be fully warm and not 20? How are you basing the 20 minutes needed?

Wow, 18-20 seconds is a LOT longer than I have been doing for a cooling flush. Do you pull water until you get to a certain temperature and then immediately pull the shot, or do you let it rebound for a set time?

Copying my response here for the wider audience and hoping for more opinions from other Cellini owners -

By 20 mins to fully warmed up - I'm referring to achieving 209-212 degrees F at the GH when flushing right before a shot.

My routine before pulling a shot is:
1. Switch on machine 15 -20 mins before I expect to pull a shot.
2. Right before pulling a shot flush for 2-3 seconds to check GH temp is at around 210 F. I interpret this as machine being fully warmed up.
3. Grind and tamp.
4. Flush until GH temp falls to 204.5 F to 205 F
5. Lock PF into GH
6. Wait for 5 - 6 secs for rebound
7. Pre-infuse for 3 seconds by pulling lever up half way. At 3 seconds of pre-infusion the GH thermometer reads at around 207 F.
8. Finish by pulling shot for 18 to 20 seconds.

I'm curious about the 20 minutes for warmup. Everything else I have read on HB and other places say you should wait at least 30 mins and more like 45 mins so that everything in the group head is nice and hot, not just the water temp. Do others only wait 20 minutes?

In your step #4, how long would you estimate it takes to get the GH to fall to that temp?

In step #6, what temperature are you waiting for it to rebound to?

In step #7, i'm curious that you are bypassing the auto pre-infusinon that happens when just going straight up, as opposed to going to the middle position and then up. Also, I find it interesting that you are doing a total pull time of 21-23 seconds, which is shorter than what most people do, 25-30 seconds.

Thoughts?

Apologies for the late reply - I was traveling and didn't get a chance to log onto the forum.

trihard wrote:I'm curious about the 20 minutes for warmup. Everything else I have read on HB and other places say you should wait at least 30 mins and more like 45 mins so that everything in the group head is nice and hot, not just the water temp. Do others only wait 20 minutes?

Yes, you are right that the recommended time is about 45 mins. The below graph which depicts the warm-up temperature curve for a CELLINE EVOL as measured & provided to me by Erics and which I'm sharing (hope Erics does not mind) reinforces that concept.


That said, my (as well as my wife's) untrained tastebuds haven't been able to distinguish between the flavour of espresso brewed after a warm-up of 20-25 mins. vs. 40-45 mins.

trihard wrote:In your step #4, how long would you estimate it takes to get the GH to fall to that temp?

Haven't timed it but would estimate around 3 to 4 seconds ( I will re-confirm this).

trihard wrote:In step #6, what temperature are you waiting for it to rebound to?

204.5 to 205.5 degrees F

trihard wrote:In step #7, i'm curious that you are bypassing the auto pre-infusinon that happens when just going straight up, as opposed to going to the middle position and then up. Also, I find it interesting that you are doing a total pull time of 21-23 seconds, which is shorter than what most people do, 25-30 seconds.

I'm trying out what I read on one of the posts, probably this is not required. Shorter pull as I'm using a single basket PF.

Still learning... searching for a Barista class around Philly. Will keep posting as I learn.

Temperature response tests were conducted on David's machine a couple of days ago. David's pstat had a range (fully warmed up) of 0.72 bar to 0.98 bar and his fully warmed up grouphead was 204.0 F. As the machine was warming up, we decided to run a test simulating Amit's brewing at ~25-30 minutes vice waiting for the machine to fully warm up. The results kinda speak for themselves.



Next was a simulation of David's normal routine. This can be a little more difficult than what one would think because in all cases, you are using the thermofilter to take the place of the normal portafilter and coffee laden basket and following the user's pattern as closely as possible.



After this, the machine was allowed to come back up to temperature and a test was run in simply flushing to a specific temperature as indicated by the thermometer and then "brewing" through the thermofilter.



In a week or so, schedules permitting, we'll run so more tests with multiple shots and maybe even lower the pstat further as steaming was reported to be excellent at the current setting.