Portafilter cold wash vs cold towel - Page 2

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TUS172

#11: Post by TUS172 »

You mean for cleaning the grouphead screen and portafilter... Yes I recall seeing it a while back.
Never gave it a shot (no pun intended).
I have gotten use to using the same technique for both cooling and cleaning this area of the levers I own. You can use cold water to cool or hot water with cleansing agent to clean and rinse. It works great! My grouphead screen and gasket remains very clean with occasional cleanings using this technique. For cleaning I usually use a glass canning jar which works particularly well. :)
Bob C.
(No longer a lever purist!)
LMWDP #012

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HB
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#12: Post by HB »

TUS172 wrote:Yes brass is an excellent conductor but consider that the portafilter makes its primary surface contact with the inner lip of a portafilter basket stainless steel (compared to brass is somewhat resistant to thermal transfer) and the portafilter basket then makes contact with a rubber gasket that is very resistant to thermal transfer.
I'll leave the mechanical explanation to engineer types, but locking in a cold portafilter has an immediate and dramatic impact on grouphead temperature for the espresso machines I've measured. The "cold wash" technique is what I use for the Ponte Vecchio Lusso for shots spaced less than three minutes apart. It is very effective at preventing brew temperature creep. Dunk the portafilter, swish, swish, lock it back in. Allow one minute in the group before reloading the basket (a nice leisurely pace if you're preparing the basket separately).
Dan Kehn

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IMAWriter (original poster)
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#13: Post by IMAWriter (original poster) »

Dan 'The Man' Kehn wrote:I'll leave the mechanical explanation to engineer types, but locking in a cold portafilter has an immediate and dramatic impact on grouphead temperature for the espresso machines I've measured. The "cold wash" technique is what I use for the Ponte Vecchio Lusso for shots spaced less than three minutes apart. It is very effective at preventing brew temperature creep. Dunk the portafilter, swish, swish, lock it back in. Allow one minute in the group before reloading the basket (a nice leisurely pace if you're preparing the basket separately).
Ah...vindicated!
And by the head honcho, no less.
(Somewhat surreptitiously Rob asks "Dan, is PayPal OK?") :lol:

Yes, Lever science be darned, somehow as you describe works for me. As a former short time La Pavoni owner, I can say that the Cremina stays cooler longer, but when I have a friend over (yes, I have a few), we'll pull 4-5 shots, at least, and the 4th will occasionally have the dreaded dark ring around the cup, unless i perform the PF wash. Does the trick, especially if I can stay within the minute as Dan describes.
Rob
LMWDP #187
www.robertjason.com

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TUS172

#14: Post by TUS172 » replying to IMAWriter »

Vindicated?... No... You are right and I am wrong... No.

With the method you and Dan are using you are cooling the espresso after it is in the portafilter not the water that is entering the basket during a 25 - 30 second pull.

You simply are not cooling a grouphead effectively through a rubber gasket nor by convection of a portafilter that is cooled in tap water.

Perhaps on the Ponte Vecchio where the grouphead is not in direct contact with the boiler (which is not the case with the Cremina and La PaVonis) a cooled portafilter may have some convection effect. Is that not one of the advantages of the Ponte Vecchio over La Pavonis?

So even if Dan is using a Scace Portafilter Thermometry Device, he is not measuring the effects of this method on a machine that is constantly being directly heated from a boiler. The effect of swishing a portafilter around in tap water and expecting it to effectively cool the mass of inside of a grouphead (that is in direct contact with a hot boiler) through a rubber gasket is ludicrous at best.

Data can be screwed around in different ways to support what you want but I know what is effective and what is not. Especially if you are also cooling a portafilter basket... or in the case of the Scace device also cooling that entire mechanism before locking it in...

If you were to lock a portafilter in a grouphead of a pavoni for say two minutes after cooling it the way you use in a "nice leisurely fashion" the portafilter would be so hot you would not want to be grabbing and holding it for too long. I could measure it but am guessing way over the temperature that you put it in at. You think you have cooled the grouphead? No not effectively at all. Do you think putting espresso cups on top of a espresso machine cools the boiler? Nope the boiler warms the cups up. It is a similar case to put a cooled portafilter on to a hot grouphead... the effect is minimal at best, especially close to a minute after you have done it.

The direct and constant heat from the boiler negates any effects of swishing a portafilter around in some tap water after 30 seconds and certainly a minute or two. Locking in a portafilter that has been cooled in tap water does not effectively cool the grouphead of a Cremina or a La Pavoni.
You even said it yourself in your first post... By the time you do your grind and get set for the pull your portafilter is "toasty warm"... this is not because it cooled the grouphead which has a constant source of heat energy... :D Sorry... I have not been convinced otherwise.

So where are our engineer types that can chime in?

A simple but effective test would be to measure the temperature of the dispersion screen with a digital probe thermometer (Perhaps I can have one of the guys at the State labs loan one to me) before and a minute after the application of a cooled portafilter and then try it with the methods used by myself and others. Flooding the lower end of the grouphead and dispersion screen by using the lever to suck up cool water from a vessel containing cool/cold water is vastly more effective I can assure you. And it only takes a few seconds to do just before you lock and load for the next pull.
Bob C.
(No longer a lever purist!)
LMWDP #012

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HB
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#15: Post by HB »

TUS172 wrote:With the method you and Dan are using you are cooling the espresso after it is in the portafilter not the water that is entering the basket during a 25 - 30 second pull.
Er, I used a bottomless portafilter. But don't take my word for this, measure yourself (e.g., over the lip with a thermocouple) or better yet, taste the difference.
TUS172 wrote:You simply are not cooling a grouphead effectively through a rubber gasket nor by convection of a portafilter that is cooled in tap water.
The portafilter ears certainly make excellent contact with the grouphead channel. In any case, try this: Lock in a cold portafilter and pull it out after 45 seconds. Is it hot? If so, the heat was leeched from the grouphead.
TUS172 wrote:So even if Dan is using a Scace Portafilter Thermometry Device, he is not measuring the effects of this method on a machine that is constantly being directly heated from a boiler.
I've used the same technique for my (now sold) Cremina and Elektra Microcasa a Leva. It's easy to taste the difference on the third and forth shot, though you really have to hustle with the directly heated group or the value of the momentarily reduced brew temperature is lost.
Dan Kehn

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TUS172

#16: Post by TUS172 »

Dan...
I will agree to disagree and not take this any further. :lol:
Any taste difference is because you've cooled the espresso as it exits the portafilter and not the water entering the portafilter basket from the grouphead.
Hey guys the day is just beginning and I have to head out for work... have a great one! :)
Bob C.
(No longer a lever purist!)
LMWDP #012

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HB
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#17: Post by HB »

Let's agree to disagree, but also to read what others have written...
TUS172 wrote:Any taste difference is because you've cooled the espresso as it exits the portafilter and not the water entering the portafilter basket from the grouphead.
As I said before, since I use a bottomless portafilter, the espresso never makes contact with anything but the basket on its trip to the cup.
Dan Kehn

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peacecup

#18: Post by peacecup »

The cold PF does work, as this is some brass-to-brass contact. So does the cold wash. Can't say which works better, but its a moot point with the PV because the tall, narrow, 45-mm group cools more rapidly than do other home lever groups (my limited experience).

More importantly than any of the above is tuning the P-stat down. I have mine as low as I can and still steam milk effectively. I can tell you in makes a MAJOR difference in the water temp coming through the group. I've always liked it low, but I confirmed this recently when pulling shots at 197 F (kettle temp) on the Caravel. I came home and turned the PV Pstat down a half turn, and my epsresso tastes a whole turn better.

PC
LMWDP #049
Hand-ground, hand-pulled: "hands down.."

IMAWriter (original poster)
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#19: Post by IMAWriter (original poster) »

peacecup wrote:The cold PF does work, as this is some brass-to-brass contact. So does the cold wash. Can't say which works better, but its a moot point with the PV because the tall, narrow, 45-mm group cools more rapidly than do other home lever groups (my limited experience).

PC
Jack...I was actually referring to rinsing the PF under water to cool as a "cold wash"...the other option was using the cold wet towel on the group. Both seems to work, but like knowing an E61 flush time, timing the cold PF in the group always gets me pretty much where I want to go.
Rob
LMWDP #187
www.robertjason.com

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TUS172

#20: Post by TUS172 »

You should try the approach that I explained... you will get much better results... If cooling the grouphead is your goal. It takes no extra time and is truly effective. :)
Bob C.
(No longer a lever purist!)
LMWDP #012