Overheated Portafilter (HX), moot point?

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TimEggers

#1: Post by TimEggers »

Curious if a portafilter can become too hot sitting in a super heated HX group? More specifically with regard to a spouted portafilter. For example I've read (from some folks with much better palates than mine) that pouring espresso straight onto ice (for an iced drink) can shock the espresso and damage the flavor (their experience).

Can the reverse also be a concern? Granted the espresso is in very brief contact with the spouts. Beyond that what if any damage is done when the espresso grounds are put into a very hot portafilter basket? Moot points or justifiable concerns? (My palate has no idea...yet). :oops:

What affect does the group temperature have in this regard, or rather what would a maximum 'allowable' temperature be? I tend to run my Anita at the top end (for easy steaming, and flush-and-go shot pulling) which leaves my group idle at 216F which is pretty hot, flushing takes care of the brew path for the water, but is the shot portafilter basket and spouts doing damage to the delicate espresso that I may not be able to detect yet?
Tim Eggers
http://www.facebook.com/TimEggers
LMWDP #202

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HB
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#2: Post by HB »

TimEggers wrote:I tend to run my Anita at the top end (for easy steaming, and flush-and-go shot pulling) which leaves my group idle at 216F...
Have you tried measuring the temperature at the dispersion screen? If not, try laying a thermocouple across the top of the puck and check the temperature after 20 minutes of idle time. Once you have, let us know if you think the group idles hot, cold, or something in between.
Dan Kehn

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TimEggers (original poster)

#3: Post by TimEggers (original poster) »

Dan I did the test as you describe. I loaded my blind basket with some of the excess grounds from a few sessions (just to hold the probe as close to the dispersion screen as possible). The readings (seen below) were taken after an hour of idle time. To my surprise there was quite a difference:



Judging solely on taste, I would not believe the portafilter spouts or basket to be an issue. They appear to be well below any temperature that would seem to harm espresso especially in a brief period of time. Note Anita is running at just a hair past 1.4-bar (the highest safe setting). I didn't measure the spouts or anything else but I would suspect them to be even cooler and less an issue. Apparently I was worried about nothing...
Tim Eggers
http://www.facebook.com/TimEggers
LMWDP #202

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HB
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#4: Post by HB »

TimEggers wrote:To my surprise there was quite a difference...
Thank you for indulging my request, your measurement is consistent with what I've measured from other E61s (i.e., they idle around 185 to 195 at the dispersion screen). The cooling flush we talk so much about should more properly be called a thermal equalization flush. That is, the HX cools down, the grouphead heats up, and has been demonstrated ad nauseum, the resulting temperature within the brew chamber is nicely consistent.

So what's the answer to my question "Does the group idle hot, cold, or something in between?" It's a trick question; the correct answer is all of the above.
Dan Kehn

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TimEggers (original poster)

#5: Post by TimEggers (original poster) »

Not a problem, it wasn't until after I started this thread that it dawned on me that I could use the probe from my roaster to do some tests on the espresso machine.

I was surprised at how much lower the dispersion screen temperature was I certainly didn't expect it (having not taken such a reading before).

Your synopsis of the flush is very interesting, seeing the numbers now I would have to agree. Furthermore now seeing all these numbers I'm amazed at how consistent the system (when choreographed together properly) can really be. If I was looking to buy an espresso machine the numbers and raw data (coupled with the 'hype' that 'temperature is everything'*) would certainly scare me, but my experience with the taste and freedom of on-the-fly temperature adjustments cements my appreciation of the HX approach.

*maybe it is, but my tongue tells me that my Anita is stable enough for my tastes
Tim Eggers
http://www.facebook.com/TimEggers
LMWDP #202

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cannonfodder
Team HB

#6: Post by cannonfodder »

Your portafilter also acts as a big heat-sink radiating out heat. The further you get from the thermosiphon lines the cooler the group gets. The difference from say the the middle top of the group bolt to the spouts can be quite dramatic.

To you comment about pulling shots into ice, my experience is exactly that. I think it goes bitter and the shock of hitting the ice, or other cold liquid will shock the suspended solids out of solution. I had a thread about this a year or two ago where we discussed it. The same thing happens with iced tea. Start with a nice clear pitcher of hot tea, dump in bunch of ice and it goes cloudy. The solids have come out of solution. During the summer, I will make my morning drinks and then pull two doubles into a small measuring cup, cover it with plastic wrap and put it in the chill chest to cool for iced drinks later in the day.
Dave Stephens