nickw wrote: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.

I have had the Rocket for 4 years and the Profitec since last August.

The output before it starts blonding is about 12-15g.

Have you tried switching the entire Portafilter between the Rocket and the Profitec and seeing if that makes a difference?

Is this causing a significant difference in taste or are you just looking at colour of the shot after a certain time . In all these post so far i have heard alot about the visual of the shot - but nothing related to taste . Perhaps just get some scales brew by ratio adjust by taste and have a little more of a relaxing time when making coffee ?

I pulled the mushroom today and there was a bit of scale on it. Very little, but just in case a small piece is causing this I am going to remove the group and descale it. I don't know what else to try and I guess this would explain the sudden change in the extraction. I'll do this over the weekend.

I hope a descale fixes it for you. Looking forward to hearing.
Cheers!

So I found the culprit. A water softener pouch that sits at the bottom of the water tank has made the water way too soft and that's why my shots were coming out weak, thin, watery no matter what I did. In the past I used the water softener pouch by Rocket which seemed to do an ok job. About a month and change ago I was going to buy a new one, but they were out of stock. I found another brand(OSCAR) so I bought it. I use Crystal Geyser water. Not all Crystal Geyser water is the same depending on the source. Mine usually has about 9-10 grains of hardness . This number will result in scale at some point so in order to bring it down closer to 3 grain I use the softener pouch. This new softener(OSCAR) apparently is more efficient than the one made by Rocket. It makes the hardness 0 grain in one hour(depending on the size of the tank) . The reason I was getting better shots on my Giotto even though I was using Crystal Geyser water was because I didn't have a softener in the tank. I decided to remove the softener pouch from the Profitec and flush the boilers with only Crystal Geyser water. I immediately noticed the difference in how the shot started to come out of the portafilter. It was thick like honey and it tasted great.

Interesting. Glad you found your issue. Perhaps worth updating the thread title to solved.

That being said I'm surprised softening has any impact. I use an inline softener cartridge and my final calcium hardness is 0. It's a cation exchange like those pouches so carbonate remains in the water. My shots haven't had any blonding issues and using large softener cartridges like this is very common.

Did you test other water parameters? Is that specific pouch raising your TDS through the roof for some reason and then you're getting poor extractions?

The whole potassium bicarb craze on this forum has not produced many 'thin espresso' complaints.

Not all Crystal Geyser water is the same depending on the source.

That is for sure.


NS: Not Specified
ND: Not detected at or above the minimum reporting level (MRL)
SCAA Target: http://www.scaa.org/PDF/ST%20-%20WATER% ... V2009A.pdf
Crystal Geyser Alpine Spring (CG-Alpine): http://www.crystalgeyserasw.com/quality.html

The whole potassium bicarb craze on this forum has not produced many 'thin espresso' complaints.

That is for sure also. BUT would it not be interesting to compare test results of that recipe to the table above with identical units?

Nice chart, Eric!

erics wrote: BUT would it not be interesting to compare test results of that recipe to the table above with identical units?

The recently posted 'easy to read' recipe:

10g of potassium bicarbonate mixed into 100mL distilled water (used as a concentrate). 3.8mL of the concentrate is added into each gallon of distilled water in the bottle system used to feed the machine.

produces a 100mg/L, 1.0 mmol/L concentration.
And 1.0 mmol/L [HCO3-] is chemically equivalent to 0.5 mmol/L [CO3--]. So expressed in the standard way for alkalinity you would have 50 mg/l (as CaCO3.)*

pHeq (for scale/corrosivity calculations) would be in the 7.0 - 7.4 neighborhood and TDS in the 100 mg/l neighborhood. Everything else would be zero.

Professor Pavlis sometimes uses a about half of his standard 1.0 mmol/L solution - see for example La Pavoni sight glass stuck trick

* Note that KHCO3 and CaCO3 both happen to have a molecular wt of appx 100 g/mol. Makes the arithmetic easy. Because CaCO3 will neutralize two protons, and KHCO3 will neutralize one proton, one mol of KHCO3 is equivalent to 0.5 mol of CaCO3.