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rsnidjik

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About rsnidjik

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    Brewing Nicely
  1. A further update: With a new pump and OPV, my Expobar Office Control was operating pretty consistently. I was still having to flush 350 ml of water to get the brew temp in the right range, but at least the machine was consistent. I was contemplating doing the thermosyphon restrictor mod but first decided to try the less invasive but possibly problematic method of adjusting the pstat downward. My Expobar is new enough (2010) to have the pstat that's adjustable with a little plastic dial. I was able to access the dial by removing only the front panel. I first tried a quarter-turn counterclockwise and got a lower idling temp, but it was still running hot (about 98º C.) and requiring a high-volume cooling flush. A second quarter-turn did the trick, reducing the idling temp to about 95º. Best of all, the flush volume needed to get to a brew temp of about 93º is now 200 ml instead of 350 ml. That means far fewer refills of the tank and less time waiting for my coffee. Flushing 200 ml feels normal; flushing 350 ml each time felt dysfunctional and dominated my workflow. I know the jury is still out on optimal brew temperature and that it's probably dependent on the bean as well as who knows how many other variables. In my case, I almost always get that nasty-looking dissipated crema when the temp is too high. I'm not getting that when I brew in the 93-94º range, and, more importantly, the taste is usually to my liking. Brew temp appears to remain very steady throughout the time of extraction, at least according to my measurements. (I'm measuring brew temperature with a good digital thermometer [Thermopen] inserted through a small foil cup that nestles snugly into my bottomless portafilter.) Steam pressure remains robust. So, I'm content for now. Soon, though, I'll tweak things further until I really mess everything up. Then I'll come whimpering back here. Thanks in advance!
  2. No snoozing here. Instead, I drink double shots of espresso throughout the day.
  3. Update to the problem that I reported in my first post: On a visit last week to the U.K., I got a replacement pump, OPV and pstat for my Expobar Office Control. (Excellent service from all four U.K. vendors, by the way. I got a bunch of other odds and ends, too.) Yesterday I installed the pump and OPV, and the problem with the delay before water would emerge is now resolved. So DavecUK was right that things were not normal. Now I'm dealing only with the standard HX problem of needing to flush the grouphead before pulling a shot. In the U.K., I ordered the itty-bitty teflon disk to use as a thermosyphon restrictor and I even have a nice new flare nut spanner, but I'm going to hold off on that mod until I get used to my machine's vastly improved behavior. Thanks for everyone's input.
  4. I'd go for this with a 30-percent-off, free shipping coupon code. Too bad the current code is expired.
  5. Nah, I'm not upset. I love my new-old machine even if it's gimpy. I'm living in North Africa, and, apart from some amazing espresso equipment in some of the swankier big-city cafés, what the rest of us have access to is stuff that Europeans have gotten tired of. People here are extremely resourceful about maintaining old machines and keeping them working acceptably well. For the most part, I don't mind being 10-15 years behind the cutting edge (except when I go to the dentist, that is). Regardless, it's a small price to pay for beautiful weather year-round and, as I type this, luscious pomegranates at the equivalent of 12p each. But I do wish I could find freshly roasted beans a little more easily.
  6. You just sent my wife into near hysterics! She knows what these boy clubs are like. I've got several things on you, though: I'm 62 years old, short, got a paunch -- and, worst of all, had to check myself from writing "HX behavior" instead of "HX behaviour" as the subject of my thread. Need I say more?
  7. Ha! Starting in about 1998, I survived eight years on alt.coffee on Usenet, where the daggers were always out for any unsuspecting noob. I deserved most of the abuse I suffered, though.
  8. Thanks for your comments. I didn't think you were talking crap. It's just that my experience didn't line up with your description of the machine (and I guess I was a little miffed that you dissed my new baby! But I'm over that now. ) The coffee isn't nice and cool -- it's about right, I'd say. The temp as measured at the group head is a steady 94.5 - 95.0 degrees C without manual flushing. That's measured with a Thermopen thermometer held about a third of the way from the center to the edge of the shower screen, about 5 mm below the screen. I don't consider that technique optimal, but it's the best I can do with what I have on hand. I'll read up on HX machines. I've done some already but clearly need to do more.
  9. I've just bought an eight-year-old Expobar Office Control and am learning to use it. My previous machine was a PID'd Silvia, so most of my learning curve has to do with getting used to an HX machine. With the Expobar, I've noticed that the machine can take a very long time to put out water through the group head if it's been powered on but sitting idle for a while. I'm guessing this is because the machine cycles cooler water through the group to cool it down to an optimal brewing temperature. Is this correct? Here's some data: At initial warm-up in the morning, if I pull a shot right after the brew light first goes out, water comes out of the group head almost immediately when I hit the brew switch. The chart below shows the wait time for water to emerge at various times following the previous shot. 5 minutes after previous shot: 11 secs. 10 minutes after previous shot: 30 secs. 20 minutes after previous shot: 42 secs. 30 minutes after previous shot: 43 secs. 60 minutes after previous shot: 48 secs. I ran this sequence a second time and got very similar timings. Once the machine is initially warmed up, steam and hot water emerge from their respective outlets without a wait regardless of the time elapsed since previous shot. Question #1: Is this behavior normal for an HX machine? Question #2: Since it appears that the machine is doing its own cooling routine, should it be necessary for me to do a cooling flush prior to pulling a shot? I don't have a good way to check brew temperature right now. Thanks!
  10. Yeah, I've been working with several different beans and roasts and then recording the optimal setting for each. I know, though, that what's optimal today may probably not be tomorrow. This is the frustration and beauty of this obsession. Fortunately, the weather where I am is pretty much the same day to day, so I don't have radical changes in humidity to deal with.
  11. I have a new-to-me Mazzer Super Jolly grinder that I've been trying to dial in. In part because I haven't had a steady supply of freshly roasted beans, it's taken longer than I expected. The other day I ground and pulled shot after shot as I fine-tuned the grinder to handle several different beans. I know I shouldn't have, but I couldn't resist drinking most of those shots. I just hate to throw coffee down the sink, even if the taste isn't what it should be. Before long, I was pretty strung out on caffeine. I saved my best, freshest beans till last. After two shots I had the grinder set right and was about to pull a third shot just to be sure. I ran the grinder, then went to pull the handle on the doser. In my caffeine haze, though, my hand went instead to the little handle on the adjustment collar. I gave it a good yank ... then saw that I had reset the grind by about 40 degrees. Ugh. Next time I dial in a grinder, I'm going to invite a bunch of friends over to drink all the shots I pull, even if they're less than optimal. *I grew up in the U.S., where drink-driving is often known as "DUI" (driving under the influence), as you probably know from U.S. cop shows on television.
  12. By the way, as much as I appreciate DavecUK's suggestions for spare parts, this Expobar machine is really pretty nice. It's a nice step up from my well-used Rancilio Silvia. You can use or not use the panel buttons. A little flushing seems to be a good idea to bring temperature in line for a nice-tasting shot, but it's not excessive. So, I can recommend it.
  13. I've ordered burrs and I believe I've found a source for a capacitor, but I'm not having success finding a contactor. Can anyone post a link? Thank you very much.
  14. Yeah, you're right about the so-called programmable buttons. I only use the on/off push button. I'm glad you mentioned this. I need to do some temp checks. Thanks again for your help.
  15. Thank you very much, DaveUK. That's tremendously helpful. Here's a front view, FWIW. It's an Expobar Office Control that's apparently been rebranded by Stracto, which I believe is a Spanish coffee distributor. As best I can tell, Stracto sells pods for home and office use and must have distributed these rebranded Expobars with a portafilter designed for pods. Over the last eight years, it made its way to Morocco, where I'm living right now. It came with a standard portafilter. I've done some shameful things in my life, but I've never used pods. [ATTACH=CONFIG]37579[/ATTACH] Yes, I'll try to get a better photo of the interior before writing to a U.K. supplier. Thanks for the advice. Over and out, rsnidjik
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