E61 mushroom no scale, but boiler scale?

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F1
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#1: Post by F1 »

Is it possible to have scale in the brew boiler while the E-61 mushroom is completely clean?

The reason I ask is because my Profitec 700 has started to produce only thin watery shots that are flavorless, but not bitter. I have been using the Profitec for over 12 months without issues. I bought a K30 vario 3 months ago and have been using it exclusively since. My beans of choice is Hologram from Counter Culture Coffee. I have been using this coffee for as long as I can remember. I get two 12oz bags delivered every week. About three weeks ago every shot was coming out watery and thin as hell with light colored crema. It tasted like crap. I couldn't even get any aroma from the shot. Of course I played with dosage, temperature, brew pressure, blah, blah, even though I haven't had to in months, but the end result was the same. I figured I got a bad batch from CCC. Next, I bought a few bags from a local roaster(NOVO coffee) that I frequent a lot and the same thing happened. At this point I figured the issue was not the beans, but maybe the K30 grinder. Thankfully I have two other espresso grinders(Compak K10, Super Jolly E). I tried the Super Jolly and the shots were still coming out the same. Next I pointed the finger at the machine. Things that could result in thin, watery shots are low temperatures and/or low brew pressure. I tested both with a SCACE and they were 201F stable and 9.2 bar stable. At this point I started to panic because I didn't know what else to check. Then I thought maybe the water even though I have been using the same water for years. I use Crystal Geyser from the Norman, AR source. I tested the water and just like in the past the results were 92 TDS and 125.3 ppm or 7 grains of hardness. 7 grains of hardness should result in scale, but every time I remove the mushroom which is at least once a month it is always clean with not even a trace of scale so I have never descaled it. The boilers in the profitec are stainless and from what I understand they are more resistant to scale, but how much more resistant I don't know. Some of the adverse effects of scale build up are the inability of the machine to heat up properly and reduced brew pressure, but like I mentioned I tested both and they are fine. Finally, I thought am I the problem? My technique is the same. I use all the tools at my disposal all the time since I am very OCD when it comes to making espresso. I use scales to measure the grinds, the extraction. I use a calibrated tamper and naked portafilter. The extractions come out evenly and with no sign of channeling. The extractions are blonding faster though which is something else I noticed once the problem started. Two days ago I went to NOVO coffee and had two doubles and they tasted great so it is not my taste that has gone downhill. I am out of ideas. :cry:

sluflyer06
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#2: Post by sluflyer06 »

Have you tried measuring your flow rate? Put a pyrex cup or scale under the group with no portafilter and run the pump for 30 seconds and see what you get. E61's come with a .6mm restrictor under the mushroom so you should get about 250ml in 30s, give or take. If you have scale clogging a line you might have reduced flow. Its just an idea.

F1 (original poster)
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#3: Post by F1 (original poster) replying to sluflyer06 »

Thx for the input. That didn't even occur to me. So I tested twice and I am getting 350ml in 30 seconds.

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erics
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#4: Post by erics »

So I tested twice and I am getting 350ml in 30 seconds.
I just measured the same flow with the same machine.

The gicleur size for the Profitec 700 as stated in their parts manual is 0.80 mm. I may try a smaller gicleur I happen to have but sorry, Wally, as I have no ideas regards your "problem".

The one item that is missing from your detailed post (nice, btw) is "x" grams in and "y" grams out. Unfortunately, that is not relevant as you are describing an experience that was fine on "Monday" but less than desirable on "Tuesday".
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at rcn dot com

F1 (original poster)
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#5: Post by F1 (original poster) replying to erics »

Hi Eric,

Do you think I can rule out scale in the boiler then? I actually have a 0.5mm gicleur that I bought a while back and was planning to test, but never did because I didn't have the right size socket. This was before the issue started. I'll go buy that socket tomorrow and try that. Hopefully that helps, but even if it does I am still gonna be scratching my head.

sluflyer06
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#6: Post by sluflyer06 replying to F1 »

I don't think you should change anything else at this point, this is a sure way to keep running around in circles chasing your tail. The gicleur wasn't the problem before, so its not the problem now. You need to figure out what changed without adding more variables. Hopefully today you'll get some more input from some pros who might have some other ideas. It certainly is odd that your temperature and pressure and flow are good and you ruled out the grinder.

Pull some water from the group into a glass and let it cool down and then taste it, make sure it doesn't taste bad.

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erics
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#7: Post by erics »

The gicleur wasn't the problem before, so its not the problem now.
I would certainly agree that changing the gicleur is not a solution based on all that has been said. However, if you do go that route, the correct size tool is a 7mm nut driver or a 7mm socket. Installing the replacement gicleur is best done using a 2-3 inch section of 1/4" ID soft plastic tubing with a 1/4" wooden dowel fitted in one end and the hex portion of the gicleur in the other.



Tasting the grouphead water is a good idea.

I don't see scale as having any effect on this problem.
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at rcn dot com

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canuckcoffeeguy
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#8: Post by canuckcoffeeguy »

F1 wrote:I am out of ideas. :cry:
Well, this is a strange one. I don't claim to have the answer, but here are some I'm throwing out there:
  • -Is your group gasket worn? Is it keeping a good seal or losing pressure?

    -Is your basket worn or misshapen or damaged in any way?

    -When did you last do a detergent backflush?

    -Have you looked behind the showerscreen? Is it clogged or gunked up?

    -Is the showerscreen damaged?

    -Are you sure your water test results are accurate?
I'm also out of ideas.

F1 (original poster)
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#9: Post by F1 (original poster) »

I installed the 0.5mm gicleur. I haven't meassured the water flow, but it looks significantly slower. I would say it looks like half of what I was getting with the factory one. Also, the brew pressure now is a bit lower. Like .3bar lower. I made some of the Hologram beans I had left, but the results were the same. I am getting some new Hologram beans tomorrow, but they will not be ready till this coming Monday(7 days post roast).

I followed some of the advice from canuckcoffeeguy and replaced the group gasket(cafelat), shower screen(Precision) and dispersion screw(generic). I did forget to mention on my previous post that during my troubleshooting I had cleaned the grinder and backflushed with detergent the group head. Anyway, I wish I had made the changes mentioned before I tried the Holograms beans I had left. The reason I say that is because I have two bags from a new(at least to me) local roaster here in Colorado called Corvus. I have never been to this roaster so I am not familiar with their beans(Genesis Black Honey). I went back to the K30 since I didn't notice any improvement going to the Super Jolly like previously mentioned. I dumped half the bag in the Hopper and since these beans looked really light I adjusted the grind a bit finer than what I was using with Hologram. I decided to start with 18g in and an extraction ratio of 1.2 and then 1.5 in 25-30 secs. Very first try I got 23g out in 26 secs. I got good aroma and a good decent flavor. Nothing incredible, but a lot better than what I have been getting lately with Hologram and NOVO espresso. Without changing the grind setting I let a second shot run for 30 secs and got 28g out. The aroma and flavor were the same, but I did get a bitter after taste about two minutes after I finished drinking the shot. Anyway, I am seeing improvement, but I don't know if it was down to the new beans or the changes I made to the group head. All the items I changed have been in the machine since I bought it. I wasn't getting any leaks during extractions and the shower screen and the dispersion screw both looked clean. I guess I'll know for sure next Monday when I try Hologram again. I checked on CCC if Hologram had made any recent changes on their beans, but they are using the same recipe.

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erics
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#10: Post by erics »

I installed the 0.5mm gicleur. I haven't measured the water flow, but it looks significantly slower.
I did too using the tools I previously posted a pic of. Flow was dramatically reduced to around 425 ml/min. I did two runs, both weighed at 30 seconds and did an average.

I will be curious to see if I can discern any differential with my typical cappy's.

But, as we all know, this goes beyond your originally stated problem.
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at rcn dot com

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