Blonding too fast. Profitec 700.

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F1
Posts: 699
Joined: 13 years ago

#1: Post by F1 »

It seems like every week I have a different problem. :cry:

I recently noticed that my shots were blonding faster than normal on a Profitec 700. Depending on the coffee and dose I never see any sign of blonding till about 27-30 seconds into the extraction. The first part of the extraction behaves like I am used to. That is color, thickness, no channeling(I always WDT), but then at about 15secs into the extraction the cone(as seen from a bottomless portafilter) gets really tight and the color goes really light(blonding). For the last 4 weeks I have used CCC Hologram, Nossa Full Cycle, Boxcar Coffee. I have been using these coffees since I can remember and they all started behaving like this all of a sudden. There is no channeling and my technique hasn't change. I always use a K10 grinder so I tried my Super Jolly thinking it was maybe the burrs even though they are less than 8 months old. The Super Jolly gave me the same results unfortunately, so it is not the grinder. I checked the temperature with my SCACE 1 and it was at 199F +/- 1.5F. Same temperature I have always used for all my coffees. Brew pressure is set at 8.8bar(as always).

Finally I decided to get my Rocket Giotto out of its box. Every shot came out perfect on the Giotto. I can't figure out what is causing this on the Profitec since everything(temperature, brew pressure) appears to be working as it should.

brianl
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Joined: 10 years ago

#2: Post by brianl »

Have you tried hotter water on it? Maybe a new blend component is a high altitude bean. I only go below 200 for full city or darker coffees when they taste bitter.

I know for sure cooler water can cause early blonding due to not extracting enough

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

No, but the same coffees pull just fine on my Rocket Giotto at the same temperature/pressure. Is too much of a change, out of the blue and concistent(every single shot now has this problem). I tried just looking at the water coming out of the group for 60secs to see if there was an obvious change in speed, but it looked the same from begining to end. The pump also sounds like it is behaving normal.

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nickw
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#4: Post by nickw »

I'm assuming the profitec used to be similar to the Rocket, and something has changed? Or did you just get the profitec?

You already established they are at very similar temp and brew pressure (that would of been my first guess too). The next things which come to mind:
- Semi-plugged dispersion screen (is the profitec clean and flowing correcly? - you could try swapping screens).
- Different flow rates (if you measure 30second of output on both machines, is it the same?)
- Are you using the same brew ratio on both machines? eg: 18g in / 36g out. Does the PF700 achieve the same brew ratio at a faster time (even with the same grinder/coffee)?
- Also assuming they using the exact same water.

A little more info may help in tracking down the difference. They are almost identical machines. (side note: why the switch?).

brianl
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Joined: 10 years ago

#5: Post by brianl »

F1 wrote:No, but the same coffees pull just fine on my Rocket Giotto at the same temperature/pressure. Is too much of a change, out of the blue and concistent(every single shot now has this problem). I tried just looking at the water coming out of the group for 60secs to see if there was an obvious change in speed, but it looked the same from begining to end. The pump also sounds like it is behaving normal.
Did you check with a scace? The Giotto is a hx if I recall.

F1 (original poster)
Posts: 699
Joined: 13 years ago

#6: Post by F1 (original poster) »

nickw wrote:I'm assuming the profitec used to be similar to the Rocket, and something has changed? Or did you just get the profitec?

You already established they are at very similar temp and brew pressure (that would of been my first guess too). The next things which come to mind:
- Semi-plugged dispersion screen (is the profitec clean and flowing correcly? - you could try swapping screens).
- Different flow rates (if you measure 30second of output on both machines, is it the same?)
- Are you using the same brew ratio on both machines? eg: 18g in / 36g out. Does the PF700 achieve the same brew ratio at a faster time (even with the same grinder/coffee)?
- Also assuming they using the exact same water.

A little more info may help in tracking down the difference. They are almost identical machines. (side note: why the switch?).
-I have been making espresso for 4 years.
-I had already removed and inspected the dispersion screen. It was fine. I swapped the screens and it made no difference.
-Tried different baskets. VST, IMS, HQ.
-I measured the flow rate at 366ml in 30 secs on the Profitec.
-It blonds so fast that I haven't been able to establish a brew ratio on the profitec. Regardles of dose(17g,18g,19g,20g,21g) it always blonds at around 15secs from lever activation. NO, DON"T SAY GRIND FINER PLEASE I have already tried it and even when I almost choke the machine all I get is a few dark drops coming out of the brew head followed by blonding only a few seconds after. I know, I know the first thing to come to mind is CHANNELING. Well, the extraction comes out as even as it can be, no spray anywhere. When it blonds it doesn't come out faster. Instead, the cone just collapses up onto the bottom of the basket and all I get is a light tan watery, disgusting, bitter shot.
- Same water. Crystal Geyser.
-It has been 5 weeks since the last time I made a normal shot in this machine. Something happened and I don't know what it is.

F1 (original poster)
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Joined: 13 years ago

#7: Post by F1 (original poster) »

brianl wrote:Did you check with a scace? The Giotto is a hx if I recall.
Yes. And I have experimented with temperatures as low as 80C all the way to 94C. I use Celsius because the Profitec 700 temperatures behave erratically when run on Fahrenheit. In Celsius it is spot on with the SCACE.

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nickw
Posts: 559
Joined: 11 years ago

#8: Post by nickw »

nickw wrote:I'm assuming the profitec used to be similar to the Rocket, and something has changed? Or did you just get the profitec?
F1 wrote:-I have been making espresso for 4 years.
Sorry, that came out wrong. I meant to say: Did the issue on the profitec just start? Or has it always been like this?
But you answered that question at the end of your last post: It's been like that for 5 weeks.

Hmm, to be honest, I'm not really sure, as:
Temps and flowrates seem good, as does pressure.
Screen, basket, coffee/grinder aslo good, as confirmed on your Rocket.

Trying to think it through, it seems like it must be something in the machine. As it's consistent and you've changed/tried everything from the shower screen onwards. As well as tested everything else on the Rocket.

The only thing that comes to mind is pressure. Could the gauge be off somehow, or could there some scale jammed inside the machine, messing with things. I don't know, just guessing now, trying to help brainstorm.

Last q, What's the approx output when it starts blonding (if you kill it there)? And with what dose size.

ShelbiRyan
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Joined: 9 years ago

#9: Post by ShelbiRyan »

I know its a pain, but a video capturing the problem may help this out. Including basket prep.

spearfish25
Posts: 806
Joined: 9 years ago

#10: Post by spearfish25 »

F1 wrote:Yes. And I have experimented with temperatures as low as 80C all the way to 94C. I use Celsius because the Profitec 700 temperatures behave erratically when run on Fahrenheit. In Celsius it is spot on with the SCACE.
I know you're saying you use a Scace but typically the PF700 PID temperature problems are when using C not F.

Agree on the video request.
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Alex
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