Bluenoser wrote:My techniques used in this thread did not use flushes.

Hmm-m. The HX espresso machines I've tested with long recovery times have idled cool. From the ECM Technika IV Profi Review:

HB wrote:...I did a long + mini flush if the espresso machine was idle for a long time, but for improved first-time reproducibility, if you have the time, it's better to do a long flush, wait a few minutes, then do a short flush. This initial "wake up" flush improves the temperature stability of nearly all espresso machines, but especially for HX espresso machines.

If you have a SCACE thermofilter, fill it with water and then let it idle for 5+ minutes. IIRC, the ones running cool will idle around 165°F and the hotheads will idle above 185°F. As these readings suggest, the so-called "cooling flush" is really a misnomer and would more accurately be called a "warming flush". I haven't studied your readings closely, but at first glance, they remind me of what happens when either (a) the group is idle for a long time and then the extraction started with no warmup flush, or (b) the group was flushed too much and the thermosyphon loop didn't restart prior to the extraction. If the case is (b), the temperature will fall off more rapidly than case (a), crashing as low as the mid 170s.

Of course, I've never used the Profitec Pro 500, so I cannot say if the above holds true for it, but it's true for the thermosyphon-restricted HX espresso machines I've reviewed over the years. They typically have an absolute minimum recovery time of 90 seconds and really need closer to 3 minutes. Of course, much beyond 5 minutes, the group cools down enough that it needs a warmup flush and ~3 minutes rebound time.

(Apologies is the above it somewhat vague, I'm recalling my experience from a few years back).

HB wrote:Hmm-m. The HX espresso machines I've tested with long recovery times have idled cool. From the ECM Technika IV Profi Review:

(Apologies is the above it somewhat vague, I'm recalling my experience from a few years back).

Edit: okay.. just watched your video .. I'll test..

Here will be the workflow...

Will let PF/SCACE and machine warm up for 45 minutes..
PID will be 256F (1.3bar steam)

Will start a timer:
00:00 - pull first shot for 30 seconds
03:00 - mini flush (3 seconds).. idea is to reheat group
03:05 - pull shot #2
06:00 - mini flush (3 seconds)
06:05 - pull shot #3
will repeat until have done 5 shots.

Note that using a SCACE is actually much more positive than using actual coffee, as the SCACE remains hot and actual coffee remains cooler. Today in trials with actual espresso, I pulled a shot and it took 15 minutes for the group to rebound to 199F before I felt I could pull next shot. That is unbelievably slow.

untoldex wrote: For me upgrading from small lever to HX/E61 would be mostly about saving time in the mornings. Currently to make 2 cappucini I pull two shots (45mm filter basket) and steam twice, which takes 10-15 minutes on PV Export (but it tastes great! )
With HX, I would put timer on smart plug, then just walk-up-and-pull double espresso to two cups, steam bigger pitcher of milk and done. I imagine it would be 2-3 minutes. For guests, 4-6 persons, it would be mostly cappu/americano, then even slightly lower brewing temps wouldn't affect taste much I suppose.

No question, that is the best workflow for 2 drinks... At PID of 258F, my group idles at 202F by group thermometer.. which means my first pull would average 202F for the puck.. Then the group will drop 5F in 3 min. so if you pull another, it will be 197F which is acceptable .. So now you have your 2 espressos.. Now steaming doesn't matter.. You get pretty good steam no matter what.. so you do big pitcher of milk and you are done..

In this situation you haven't been affected by slow rebound.. But the next espresso, if you wanted a 200F extraction, might take 15 minutes of wait time.

Also, if you are experimenting with espresso to learn about taste, it is not uncommon to make 5-6 shots and vary things like dose and grind.. to see how the taste is affected.. well.. your brew water is all over the place because of slow rebound.. and if you wait until the group reheats each time, you are forever.

I have profitec pro 500 without pid and i have modified it with a restrictor. I don't have a scace but i did a test with a blind filter with a ktype on the porta and i got results that are roughly as below.

The seal was not solid so water was leaking from the porta so i think the temp was off a bit in this.

I am running 1.2bar max
Idle was 198.8 on eric's

Time - Eric's - K-Type
3s - 207 - 194
10s - 206 - 197.6
12s - 205 - 197.6
15s - 203 - 195.8
18s - 202 - 195.8
23s - 198 - 194
28s - 195 - 192.2
32s - - 183.2

This is not a 100% result as water was leaking and i am using different hardware compared to dave, but its a datapoint. What this tells me is that:

- I go by taste and this works for me, I set the brew pressure to be different than what came from factory 9.5bar vs 10from factory. What it also says that with my machine i can get the optimum temperature (possibly) but its on the decline as it is brewing.
- Eric's thermometer is useful at 15s in to tell me what sort of temperature should i expect.
- My machine cannot do one set temperature from begging to the end of shot.
- It somewhat aligns with dave's finding that eric's thermometer is reading higher temp than on the puck, which in a way makes sense that the mass of the e61 is absorbing energy and while its passing the thermometer its stating temp at X F and by the time its hitting the puck its delta is -5F.
- My light coffee's are acidic, my medium coffee's are less acidic. If i used a dark roast it usually has no acidity. I prefer medium roast coffees as the flavour profile is in a wide spectrum for my taste.

I think it would be interesting to see if i can do the same experiment as dave with same hardware and see what i get. It would also be interesting to see what others with similar hardwares get in terms of their findings.

untoldex wrote:I'm quite puzzled now.
Just talked to person who has Pro 500 PID, and he is really happy with the machine for almost 1 year. He hasn't noticed any problems with temp when pulling few shots one after another. They taste great for him so didn't even bother measuring brew temperature. But he is doing small flush before each shot, to clean and get more fresh water into HX. He is using medium roasted blends and drink only espresso.

For me upgrading from small lever to HX/E61 would be mostly about saving time in the mornings. Currently to make 2 cappucini I pull two shots (45mm filter basket) and steam twice, which takes 10-15 minutes on PV Export (but it tastes great! )
With HX, I would put timer on smart plug, then just walk-up-and-pull double espresso to two cups, steam bigger pitcher of milk and done. I imagine it would be 2-3 minutes. For guests, 4-6 persons, it would be mostly cappu/americano, then even slightly lower brewing temps wouldn't affect taste much I suppose.

Now if you're talking about Robot and Bellman, then perhaps it would be similar time comparing to "full rebound" on HX, but it will require many more steps to perform and paying attention to more details. I see HX as much more convenience, despite those longer waiting times. So perhaps it's some kind of trade-off.

HX rabbithole is confusing for sure, one day you have realized and read that A,B,C is true, then the next day everything is negated. Dave's tests are fantastic for the HX rabbithole and gives us a solid datapoint from an end user for this specific machine. The E61 head would create similar issues with any type of machine db vs hx. As dave was saying a saturated group may solve these issues but i have no experience in those (yet).

I would suggest if you or anyone wants to get an HX machine, you try it yourself and taste the coffee and decide from there fact for hx is you will hit the desired temp at the puck but it would be during a declining profile.

There are many datapoints in terms of research by professionals about what temp is best for what coffee and it is all by taste, i know for lighter roasted coffees i want a lower brewing temperature to retain their "floral" and "fruity" flavour profile. So for me a declining temperature profile works. This does not mean i won't jump on a machine that does not have a declining temperature profile. If money was not an issue i would get a lm or gs3 no questions asked and never look back.

Bluenoser wrote:... it took 15 minutes for the group to rebound to 199F before I felt I could pull next shot. That is unbelievably slow.

I don't think the eric's thermometer at idle would give you any useful information except for the fact that the thermal mass is heated upto certain point with the water. I don't think nor believe that at idle the value on the thermometer is of any great value except for the fact that it is heating.

The thermometer is ONLY useful when water is passing through it.

I do use idle temperature to gauge my flush timing but otherwise i tend to ignore it as of any factual value because the thermal loss to the atmosphere would also change the value of the temp at idle.

I watched Dan's (HB) video and tried to duplicate the test that he did in the link he provided above. The premise was that a 'warm-up' flush is needed at about 3 minutes to heat the group. While that seemed to work in his case it did not with the Profitec Pro 500 PID.

From Al's comment above, the question is whether Erics reading means anything when water is not flowing. I am finding on my machine it absolutely does. Whatever that group thermometer is reading before the shot, is pretty close to the shot average temperature. One premise is that the group will cool off and so show a very low temp, but a 3 second flush will boost it back up, and the shot will still come in about 200F. Not so, from my video in the link below.

I included the full video to prove that there is nothing 'magical' happening between shots. The interesting stuff happens at 3, 6, 9 minutes. I warmed up the scace/PF and pulled one shot. That was at 200F. Just before 3 minutes, I pulled out the PF and put a small amount of cold water into the scace (maybe an oz) to cool the 'puck' and thermometer. This attempted to simulate a new coffee puck which would be at room temp. At 3 minutes, I then did a 3 second 'heating' flush. Then waited about 10 seconds and did a 30 second shot (about 50g) . I repeated for 4 shots.

Dan mentioned that in his machine a 90 second rebound wait was critical. I gave about 180 seconds.

The end result is that each shot declined in average temperature: 200F, 196F, 192.5F, 189.8F.

One activity that prompted all this work happened about 4 months after I got the machine. Before purchase, I had done tons of research and read nearly every post about HX machines.Also watched WLL videos on the stability of this PID design. Finally pulled the trigger and ordered my unit (June 2018). Was several months figuring out I had a brew water issue, but thought I might have developed a workflow to fix it. I had 3 friends over for espressos.. First was great.. second friend said his was good. The third friend spit his out. At that time, my PID was lower and likely his brewed in the 180s.

My final comment is that I think manufacturers consciously do not try to provide any benchmarks or objective performance marks for their products. Knowing that beans, tamping, workflow can affect performance, they choose not to try to characterize their machines. This makes it impossible for the user to know if anything is wrong with the machine, or their use of it. By the time the machine is characterized, it is not able to be returned. (mostly because you need a #&!% lab to validate your belief.

I'll also add that yesterday, I made 2 espressos.. after the first, it took 15 minutes for my group thermometer to climb back up to 199F. Since 'warming flushes' don't seem to really do anything in my case it is just brutally slow if you want to duplicate your last shot.

Currently, the only cost effective machine I'd consider at this point in time is the Breville 920. Above that, I'd look at DE1 and Londinium because I have more faith in the people responsible for their designs.. Lelit looks interesting. I can't drink enough coffee to justify LM. But I also believe I could make as good espresso with a Bellman and a Robot at this point. I'd have saved a lot of money. And certainly after this machine, the brew water temperature of the Robot might be a step up!

Dave,

Very interesting about your machine, and i agree with everything you have said, except for i think your machine and mine behaves a bit differently.

- Are you able to find someone or someplace where you can use the same model of your machine and use it to see what kind of results you get? I am wondering if there is something off with your machine? A friend of mine had a rocket where results were all over the place he did exchange it with the same model of the machine and things became consistent.
- what is your brew pressure set to? i found the profitec out of box had the brew pressure to be really high, that's why i had asked what did the scace tell you about brew pressure?
- Another thing i would suggest is try a local coffee place and ask them to make a shot out of the beans you are bringing home so you have a flavour baseline?
- This may encourage you to aim for a flavour based results and tend to ignore the temperature bouncing up and down on the machine.


I find my machine does a decent job at producing consistent results for coffee even if i do 4 shots back to back, but i do need 7mins minimum for recovery.

This is a little snippet from my log for 4 shots done back to back with eric's thermometer readings, you can clearly see a declining temperature profile for all the shots and the 15s mark temps to be lower than the shot before:



I do wish these over $1k machines did have features that let you see the temperature and they engineered them to have consistent temperatures throughout the shot. But alas, it is the italian way.

Cheers

I can't get anyone to admit there is an issue with my machine so I could never get an exchange. I just sent it to IDC who replaced the SSR and they claim they did a SCACE test and did 3 shots that all came over 200F.. That does not align with my results.. and so they would never exchange. I don't know anyone else in town that even has a real espresso machine.

And you are right.. mine may not behave like every Pro 500. However, there are other users who have claimed similar issues. I wish it was a $1k machine.. Current price for this is $2300 + 15% tax = $2650.

From your readings you are brewing about 192-194F (drop 3-5 degrees for Eric to puck). The peak doesn't translate to the puck.. So you might find it challenging to actually brew light roasts that require above 200F. Your current beans might work well in that temp range.. but you'd need to see 204 on Eric ... 15-20 seconds in ... to get 200F at the puck (according to data from my measurements and this aligns with other research on HB). Now I agree that one should not obsess about temperature.. its all about taste. But if you want to really see the effect of 200F extractions, you might have a bit of a wait as well.

The brew pressure it set to about 9.5bar by gauge on machine, which should translate to about 8.5bar brew pressure. The SCACE I have is only a temp SCACE.. There are only a few local coffee shops.. and no real baristas .. so I could never get a flavour baseline here.

I agree re: my temp, but for me the only way out would be LM or GS3 so i am just sitting on it and as long as flavours are ok i am ok with the machine. At a local place i had their espresso blend shot and it was fruity as heck for a medium dark roast, so my baseline was set and i used the same beans to align it to my routine (they used a gs3).

I find the higher i get to temps the coffee starts to taste off, it tends to have a powdery mouth feel which along with bitterness makes the coffee a bit unpleasant for my taste. I find my sweetspot is around 199-197F (on erics) 15sec in to give me my best results. But ideally we do want to be 198F-200F at the puck.

Another trick you could do is move your brew pressure down a bit more which would reduce some acidity along with other flavours as well, try it at 9Bar at the dial. Good to know your pressure is set a bit lower than factory, i found mine was set way to high. Each notch is about 1.25bar so i have mine set to 9.5 as well.

I rotate my coffee to try out new coffees but they all tend to be in the medium to low roasts and my understanding is that you do not want high temperature for those as it would diminish the "fruity" flavours.

If you every come to the gta area you are welcome to pop by and see how if in any way my machine differs or if it gives you the same results.

For IDC i would try to press them a bit and say the machine wont hit good temps and that all your coffees produce the same results and its not enjoyable for an expensive machine. Suggest they send you their device so you can videotape and send them the results, too bad there is not an easy way to compare and get things looked at based on your location.

Radio.YYZ wrote:Another trick you could do is move your brew pressure down a bit more which would reduce some acidity along with other flavours as well, try it at 9Bar at the dial. Good to know your pressure is set a bit lower than factory, i found mine was set way to high. Each notch is about 1.25bar so i have mine set to 9.5 as well.

For IDC i would try to press them a bit and say the machine wont hit good temps and that all your coffees produce the same results and its not enjoyable for an expensive machine. Suggest they send you their device so you can videotape and send them the results, too bad there is not an easy way to compare and get things looked at based on your location.

Yes.. I reset the pressure lower some time ago.. I can play with lower.. And who makes a dial with 1.25 per tick??????

I thought light roasts are harder to extract.. so two options.. higher temps.. or lower temps and longer extraction at less pressure.. Our machines can't to the latter; (unless you really tweak the Pressure relief).

Too much work to keep prodding IDC and Profitec.. so I have a very expensive machine that can make 2 good shots.. after an hour warmup..