I have an andreaja premium, about 4 years old. I've been having some issues with it and finally bought a scace2 to help figure it out. The other thing is I wanted a good view of the the HX flush cycle. The thermometer in the cup wasn't working.

What I found is that if I bleed off the super heated water off the top the temp comes down from 215 down to 208 - 205 or so. The heat light comes on a couple of times. I try to time it to let it cycle, then I run the pump so more to get down to 200. But there is a point where the bottom falls out of the temp right around 202 - 200. If the temp goes, it drops to 194 and easily take 15 min to recover to 202. The other issue I found is that I when I was getting the temp stable then I would steam the milk and then brew. I thought the temp was within a deg of 199 but it was not, down to 194 after I steamed the milk. I'm trying to get the machine to hold at 199 - 198 to brew, but I don't get why the bottom falls out of the temp after it was idle and just trying to bleed off that super heated top.

I finally did a full de-scale a few months back - long over due. Do I need to do it again, or is the heating element shot. Or is this just the andreja and all the HX's.

Thanks,
Jim

After a 50-60 minute warm up: What are you measuring these temperatures with? And what is the boiler pressure reading when the heating element just cuts off?

A couple of things I'd recommend, to eliminate variables:

1. Make sure your Scace and thermometer combo are calibrated. Maybe you did this, but since you didn't say so...

2. Get out a spreadsheet and run through many cycles so you understand what the machine is doing. Time a series of flushes/recoveries/pulls while changing variables (e.g., 12 second flush with 25 second recovery, 13 second flush with 25 second recovery, 12 second flush with 27 second recovery, etc.), but keep the pull length the same (e.g., 35 seconds), and keep the warm-up time the same between tests (the machine should be fully heated and stabilized). You should probably run about 20-30 variations to record the net effect of small changes (it helps if your thermometer can output its results for graphing -- often easier to understand something with a picture). Then run the entire test series again to see if you get the same results (you should if your room temperature is about the same). This is arduous and time consuming, but extremely helpful to understand how your machine works.

You may find that given the size of the boilers and heating elements that there is no way to keep a mostly even temperature over a long pull. I can keep my Vetrano within a tight enough range for the coffees I like, but at best there is still a 4 degree drop regardless of anything I do, and with most flush/recovery variations there's usually up to a 7 degree drop.

The other thing to remember is that these are Scace measurements, which will almost certainly differ from the dynamics of actual pulls with coffee in the basket. Ultimately you need to let your taste buds determine what is best, but working from the table of results calculated as described above will help you zero in on the optimal workflow in a methodical and repeatable way. And is also very useful starting point when you're looking for the best combo with a new coffee.

It's time to start keeping better records and documenting the flush routine. I am using a recently calibrated / certified fluke 54 II B.
I'm trying to avoid overdoing the flush cycle but I still think i'm brewing a little too hot.

I have set the OPV pressure and it shows 12 bar on the machine and the scace2 shows 130 psi. Which should be 9 bar.

I was trying to get one of the intelligentsia kenya SO's to work, but it wasn't happening. Now i'm using their analog. It's fresh beens since I live in Chicago. I will let taste make the decision, but I think these are finicky to get right. I would just like to get the machine stable.

Thanks,
Jim

This is part of my notes from 2 years ago. SCACE plus Eric's thermometer. Eric's thermometer is not a must, but it helps a lot if you want to be really accurate.

Machine Rocket Giotto PP V2.
OPV set at 10bar with blank disk.
PSTAT set to cycle between 1.0-1.2bar.
Machine idle for 1hour idles at 207F at the group.
SCACE portafilter in the group for 1hour.

My simulated routine:
1.Remove portafilter.
2.Flush 4.5oz.
3.Wait 1min to simulate my prep time.
4.Lock portafilter pull 25 sec shot. Fluke temperature reads up to 201.5F and then starts to go down slowly and by the time 25secs is up it is showing 200.3F.

If doing multiple shots in a row that's where Eric's thermometer comes in handy. You could simply use time after the end of the last shot, but that way is not always very accurate. For example:

At the end of that first shot I remove the portafilter for 2-3secs to simulate knocking out the grounds(I know very OCD). I lock the portafilter back in the group. Eric's thermometer is showing around 197F at this time, but still slowly going down. At the three minute mark Eric's thermometer shows 197.3F and slowly going up. I remove the portafilter and wait 1min(prep time). At the 4 min mark Eric's thermometer is showing 198F. I flush 2oz and pull. SCACE reads 201.8F and by the end of the 25secs it shows 201.1F. Now, I could simply use time instead of Eric's thermometer, but sometimes at that 4min mark Eric's thermometer is showing 197.3F or 198.5F and so on. So if I flush the same 2oz at 197.3F or 198.5F then I will get a slightly different reading on the SCACE. With Eric's thermometer if I pull at 198F at the group then the SCACE reading is basically the same every time.

After that I made several tests with different flush amounts to see the impact in the SCACE reading. I would try 2.5oz instead of 2oz and record data. Then maybe 1.5oz instead of 2oz and so on.

F1 wrote: I flush 2oz and pull. SCACE reads 201.8F and by the end of the 25secs it shows 201.1F.

That's remarkable temperature stability on your Giotto. I can only dream of that with my Vetrano.

Thanks for explaining your methodology, really helpful.

I am using a recently calibrated / certified fluke 54 II B.

Certainly the Fluke is a fine instrument but the idea is to calibrate the Fluke and the temperature sensor as a SYSTEM. All you need to know is your altitude and current barometric pressure.

I get the flush routine, but i'm trying to understand why the bottom is falling out of the temp when I brew. If I bring the temp down from 210 to 202 about 3oz of water and let the machine cycle a couple of times - about 1 minute, run the shot. The pressure stat is at about 1.2 as well. If I test the temp after it's 193. Way too low. It's like the opv is just mixing water from the boiler and tank.

gj91 wrote:It's like the opv is just mixing water from the boiler and tank.

Eric's the authority on the subject of the "flush and wait" technique, see Ideal brew temperature management by HX espresso machine type for hints. IIRC, the Quickmill Andreja is a mixer. If you flush too much or don't allow enough rebound time, the brew temperature will plummet towards the end. That said, I agree with an earlier post:

Balthazar_B wrote:The other thing to remember is that these are Scace measurements, which will almost certainly differ from the dynamics of actual pulls with coffee in the basket. Ultimately you need to let your taste buds determine what is best, but working from the table of results calculated as described above will help you zero in on the optimal workflow in a methodical and repeatable way. And is also very useful starting point when you're looking for the best combo with a new coffee.

And add my words of agreement from another post:

HB wrote:It's a common misconception that the thermofilter simulates a coffee puck (the same point came up during the review). That's not its purpose. Greg designed it to measure the consistency of the brew temperature, and in that regard, the Lusso performed quite admirably. Measuring the puck's "brew experience" is more difficult. Where do you place the probes? Can your readings be compared to mine? The thermofilter measures the water temperature at precisely the same location below the dispersion screen. It's a great tool for optimizing your routine, but its readings should not be strictly interpreted as the actual brew temperature for the reasons Tim cited, among others.

At this point, I would note a slow paced easy routine and put the Scace in the drawer for a week or two, then return to it when you have some taste notes.

Well, I think I may have the pressure stat set a little too low. someone earlier said 1.2 bar. I do have eric's thermometer and have had it from day 1. I'm going to watch that more closely. I thought with the scace2 it would have a more narrow temp spread, but it's not. With the scace2 I can see the temp fall off the cliff if I overdo the flush, or not let enough rebound time. It's now back to just a simple flush to bleed off the super heated top. maybe the 2nd or 3rd post had a pretty detailed flush routine. I think the key is to let the machine rebound.