In this test, I attempted to duplicate WLL video results for their Pro 500 PID at: They pulled 10 shots at 3 min intervals and got within 1.1F of 200F (they did not flush before any shot) .. wow.. this info is what I based my purchase decision on.

To try to make the results as positive as possible, I actually upped the PID to 256 and only ran the shot for 25 seconds (rather than 30)

I did 5 shots, not 10 as WLL did. As you can see, the thermosiphon in my machine cannot keep up. In shot #5, the average temperature is only 193.5F.

So I'm guessing WLL's restrictor is slightly different in size.. either manufacturing tolerances or different revision. It is impossible to tell. This machine has exhibited this behaviour since new, so don't think its a scale issue.

There is a suggestion that flushing might help speed up the recovery. I cannot see how this can help. However, I can change the workflow slightly if someone wants for the next round. Give a sound reason why a different workflow might help. (might help me learn an effective flush technique)

Note: I just got this machine back from my vendor who replaced the failed SSR .. I specifically asked them to do a SCACE performance test along with the repair.. they told me it measured above 200F for 3 successive shots.. not sure how they got their results.

It is clear, though, that without flushing, I need to wait until the idle is about 200F before pulling a shot. The only way I can think to speed this up, is to increase the PID even more.. possible 160 and then have the group idle above 200 and do flushing to cool. This is way beyond Profitec's recommendations.

Today, I checked the rebound characteristics of the thermosiphon.. Here is the workflow:

Bumped the PID up to 258F
Warmup: 60 minutes: Group idle: 202F

Pulled shot #1, steamed 200ml water to 140F
waited until group thermometer showed 199F

Pulled shot #2, steamed 200ml water to 140F
waited until group thermometer showed 199F

Pulled shot #3 - no steaming
waited only a few minutes and pulled shot #4

Brief conclusions:

The rebound is rather slow. Making an 8oz Latte requires that you cannot make another espresso until the 8 minute mark. (that includes time to make first espresso and steam milk)

If you don't wait until Eric says you are at 199F then the brew water will be below the desired 200F

If you had guests that all wanted a latte (I find most friends start their espresso journey on milk-based drinks).. you'll be about 20 minutes making the 3 lattes.

I think I've satisfied myself on how my machine works.. Here is my editorial on my Profitec HX journey.

HX designs with the new PID make espresso brewing ultra stable and simple. This could not be further from the truth.. Unfortunately I fell for this and thus began my purchase.

This (and maybe most new HX designs) machine was not usable as delivered. Profitec recommended the PID be set to 248F and I spent a month producing sour drinks and trying to fix by adjusting grind and dose.

I then began assembling a litany of thermometers each faster and more accurate, ending with thermocouples and foam cups. None provided any full-time monitoring and most I could not get to provide really accurate results. I stopped just short of building my own mini-SCACE. Finally I purchased Erics thermometer and only then did I start any real progress on the brew water temperature journey.

However, some espressos still tasted off and I was unsure how closely the group thermometer tracked the actual brew water. Through the generosity of a distant espresso enthusiast, I borrowed a SCACE and finally could benchmark my group thermometer reading.

There is absolutely no way that I can understand how anyone could troubleshoot espresso taste problems without confirming where their brew water temperature is.. and no way I can see to do that without the installation of a group thermometer in ANY HX design.

Manufacturers like Profitec have virtually zero useful information on their web site about the characteristics of their HX design that can guide the user. With two contacts to Profitec in Germany, the second containing detailed data.. I received these two replies: 1) we are sorry you are not happy with your machine.. it could be beans, tamping, etc and 2) work through your supplier. The problem is that this is a bit of a black art and so suppliers have so many brands, each different, and aren't expert in every design. Thus the benefits of companies like Decent and Londinium and others who take a more personal interest in user's experiences.

The restrictor in this Thermosiphon loop design causes really slow rebound. For me this caused 2 issues:
1) I could not make multiple drinks in a timely manner for a group of, say, 6 (you'd see here that might take an hour)
2) I could not easily experiment as getting the TS to a hot state was frustratingly slow.
I consider this unacceptable for a $2500 machine.

To understand how to effectively use my $2500 machine, I had to gather nearly $800 in monitoring equipment.

My techniques used in this thread did not use flushes. They will only be necessary if I increase my PID above 258F.

The group thermometer is ALWAYS about 5 then 3F above the actual brew water temp (after about 10 seconds in). This is similar to the flush-and-wait technique of old machines. It is easier to always wait for any back-siphoning to stop before pulling a shot so you can rely on the group thermometer to be 3-5F above the brew water temp.

One can play with a flush-n-go technique, but it took me 18mo. to get this far.. if I have to go that far, its either a BDB or a Robot.

I have no idea if my machine is representative of the characteristics of all Profitec Pro 500 PID.. but if it is, hope some of these graphs give users an idea of how their thermosiphon may behave so that they can have more confidence in their brew water temps. I do not think each Profitec Pro 500 PID would need to be set as high as I have set (258F) as I suspect the TS loop is so phiniky that manufacturing tolerances may make some significant difference in recovery. But only a group thermometer will let you know.

Dave

Hi Dave
At what time does the scace temperature meet the Eric's thermometer? (Example 8 seconds into the pull they were both xx temperature)
Did the temperature of the group head thermometer ever follow the scace thermometer


Thanks

Randy

Look at the graphs and you'll see that the SCACE and Eric never "meet" exactly.. but they track each other really well after about 10 seconds.. So 10 seconds in if Eric reads 205, your brew water according to SCACE is 200.. in 20 seconds if Eric reads 203, your brew water might be 199. At about 10 seconds, Eric is about 5 deg high and at end of shot it might be only 3F deg high. The reason they can't exactly meet is because there has to be a temp drop from Eric's probe in the group, to the puck..

Bluenoser wrote:...One can play with a flush-n-go technique, but it took me 18mo. to get this far.. if I have to go that far, its either a BDB or a Robot.
...

Dave, I actually ventured into DB machine (i know you mentioned the breville db - i have no experience in that). But i found the dual boilers with e61 will probably have similar heat loss issues, but it will be more consistent perhaps as you are independently setting brew boiler temp.
I think the only way out of this would be a LM or GS3 or Slayer.

I found this thread interesting.

I had a Pro 500, non pid version, with an Eric's style thermometer, adaptor, thermocouple,and digital readout, installed.

Had recovery times similar of up to 10 min between shots. Was on the phone with WLL a few times about it. They had no idea or way of solving. I increased my pstat to 1.4 and while it made it quicker recovery, not by much, I had to do a much longer flush.

Sorry to hear that my experience is not limited to me.

Long story short, sold the 500 and now proud owner of a Lelit Bianca.

So if anybody is in need of an grouphead thermometer pm me. I have no use for it now.

Radio.YYZ wrote:Dave, I actually ventured into DB machine (i know you mentioned the breville db - i have no experience in that). But i found the dual boilers with e61 will probably have similar heat loss issues, but it will be more consistent perhaps as you are independently setting brew boiler temp.
I think the only way out of this would be a LM or GS3 or Slayer.

I think any machine with an E61 needs temp sensing near the screen. Manufacturers of the traditional big-metal machines seem unwilling to provide that information. I've seen a few posts of users struggling with the DB Pro 700 (E61). Shots are sour even with PID displaying 200F. Reason was 'offset' setting in PID was set to an improper number (or zero) and no way to tell without some way to actually measure water closer to exit. With saturated groups (Breville DB, Pro300) there is much less loss and design can keep brew water much more predictable.. Then no need for thermometer on group.

I don't think one should need to pay LM (over 6k$ can) or GS3 prices to get a reasonable espresso extraction for home; or have to resort to SCACE measurements to use their machines. I've actually been thinking of buying a Bellman for steam and a robot for espresso. All this would be under $1k and have virtually zero maintenance. At up to 10 minutes a latte, I'm not sure the robot would be slower! And with practice you can do manual pressure profiling. You likely can get better espresso from medium and darker roasts than from some of the $3k pump machines. The other cost effective solution is the Breville 920.

The thread above shows that my experiences are not unique. Profitec may be unable to manufacture HX machines that all behave the same, thermally.

I am impressed by Lelit's efforts in design. Their Bianca is well regarded and the MaraX looks like a solid attempt to address the design issues with HX use for home.

I have a robot and it makes espresso at least as good as my rocket and better when using light roasts. Whilst I've loved the journey of getting to know the hx and caring for it with water recipes and descaling etc the ability of the robot to do things the hx cannot led me to getting a de1. Best of both worlds. Considering the cost and ease of use the robot would be my choice if i only drank espresso and could only have 1 device. But i liked what i could get from the rocket for some coffee so if i didn't have the de1 i would be keeping both.

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.