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DayZer0

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About DayZer0

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  1. I'm pretty happy with the taste of my espresso. I was just interested if anyone has a picture of the 'high temp dark ring' phenomenon. Purely out of curiosity because it's written often but never shown! Sent from my SM-G975F using Tapatalk
  2. Yes. I'm assuming that my puck temp is relatively flat, about 1 degree below the GH temp. I suppose this means that my brew temp at puck is roughly what my 'settled in gh' temp is. Should be easy to remember! I'm not actually concerned about hump/flat, my goal was just to understand my machine better. My only nagging doubt is this. Is my ECM machine really performing so differently to the Rocket. Or are there issues with my GH temp measurement with the Coffee Sensor. Hard to know for sure unless I actually measure puck temp like you did! Sent from my SM-G975F using Tapatalk
  3. Yes. I'm assuming that my puck temp is relatively flat, about 1 degree below the GH temp. I suppose this means that my brew temp at puck is roughly what my 'settled in gh' temp is. Should be easy to remember! I'm not actually concerned about hump/flat, my goal was just to understand my machine better. My only nagging doubt is this. Is my ECM machine really performing so differently to the Rocket. Or are there issues with my GH temp measurement with the Coffee Sensor. Hard to know for sure unless I actually measure puck temp like you did! Sent from my SM-G975F using Tapatalk
  4. I've read many times that a dark outer ring in the crema suggests that the brew temparture was way too high. However, I've never managed to find pictorial examples of this online. Trying to make sure I understand the difference between too high a temperature and that ideal tiger striping. Can anyone help? (p.s. I know crema analysis isn't everything, but I'm just intrigued given that I've never seen a clear demonstration of something so oft repeated) Sent from my SM-G975F using Tapatalk
  5. Excellent thread thank you! I had a few related thoughts: The 1.1 bar vs 1.5 bar comparison was particularly interesting as it somewhat mirrored my experimentation above. Your graph provides an interesting answer to that common question of 'how does GH temp relate to puck temp'. Is it correct to conclude that the delta here is related to the boiler temp (really the HX water temp)? I.e. HX water being much hotter than GH means a 2 deg difference and cooler HX water (but still above GH) might be only 0.8 to 1 deg. It's not as simple as assuming it's always 2 degrees! Now that i'm running lower pressure I tend to do no flush (1.1 bar). GH idle at 94 - the hump is to 95 and then comes down to 93-94. I would guess that my puck temp is another degree lower. Only downside is a painful recovery after 2 shots. Another observation is that the hump at the GH is far less pronounced for me. At 1.1 Bar, GH idle is max 94 and the GH shot temp would peak at 95 and fall back to 94 At 1.5 Bar, GH idle is 96-97 and the GH shot temp would peak at 98 and fall back to 97 Any ideas why I'm seeing such different GH temperature and response?
  6. Good tip. I've always been rapid with the lever thinking that helps suck out more water and have a better knock out. I'll experiment Sent from my SM-G975F using Tapatalk
  7. I was thinking about this thread again today. I've been finding that my pucks almost always knock out in two discs. Even if it comes out in one knock, the puck is clearly fractured in two halves in the knock box. The top half is always very dry. The bottom half looks darker / moist and tends to leave the odd clump like in the PF similar to OPs photo. This is with a straight walled Vst. Sent from my SM-G975F using Tapatalk
  8. Hi I have an ECM Mechanika and use 18g VST and most of my knock outs look similar to that. It tends to be a tiny bit better if: Dosing up to 19g When pulling longer shots at the same grind size - e.g. 30g shot wont knock out as cleanly as when I go for 36g The beans make a big difference also. I love BB's blends (I normally use Gaslight), but I have used coffees from elsewhere that knock out cleaner than those from BB. I don't understand why this would be! In any case, no impact on flavour. I would generally rinse my PF anyway. However, I might still brush out any remaining grinds before rinsing, so a clean knock-out can save a few seconds!
  9. Hi All I just wanted to share some experiences playing with my machine and a coffee sensor in recent months. I’d be interested if these observations are in-line with others and if you agree with the hypotheses. For many of you there will be no revelations here! Coffee Sensor initial observations 1) I got the black one. It was very easy to install and blends in well with the machine, probably because it matches the black valves. 2) The machine takes a lot longer to heat up than I original thought. It might hit target boiler pressure from cold in 20 minutes, at which point the brew head temperature might not even be 80C. It was taking at least double that time to reach brewing temperature. Seems like an oversight in the manual. 3) It’s well known that the thermometer reads group head pressure when the brew lever is down, and then the water flow with the lever up. However, the difference in readings is rarely more than a few degrees. For example, during heat up, if the thermometer reads 80 degrees (lever down) and then you lift the lever, I was expecting the water temperature to quickly rise to 92-94C. The reality is that it might jump to 82-84C during a 10 second flush. In hindsight I think there are two reasons for this, firstly, the water temperature will always be close to the group head (one heats the other?); secondly, the high mass of the group head and thermal stability means the water quickly heats/cools to its temperature. 4) The majority of the ‘cooling’ of the cooling flush often occurs after, not during, the flush. You are actually flushing hot water, and it’s during the recovery that colder water brings things down Cooling flushes and brew temperature – higher boiler pressure Machine idling at 1.45-1.5 bar Group head idle temp - ~96C This is how my machine has always been running. I was used to substantial flushes. During the flush there would be flash boiling and the temperature would increase to 98/99C in a second or two. I would stop the flush as soon as the temperature showed its first decrease e.g, (96 – 98.0 – 98.3 – 98.5 – 98.3 (stop!). This was equivalent to a couple of seconds after flash boiling stops. Circa 150ml/200ml. I would then grind/tamp and during this 30sec pause the group temp would drop to about 94/95. I would then brew and get a solid 94 during the shot. Cooling flushes and brew temperature – lower boiler pressure As a lock-down inspired experiment I lowered the boiler pressure down to 1.15-1.2 bar. Group head idle is now ~94C Very little to no flush is no required. I was really shocked how much difference it made! If I brew without flushing, the temperature spikes to ~95C and stays there through the shot. If I want a 93/94C brew temperature I just have to flush for a 2 seconds before grinding (~20ml) Steam power still seems ok, not sure I’d notice if I wasn’t looking out for it. However, I only steam small quantities of milk, circa 150/200ml. Shot to shot rebound isn’t great. After a shot and then a very short cleaning flush (1 sec) the group temperature could drop to about 90C. Then brewing within a few minutes might get a 91/92C flow temp. On balance, this lower pressure might be better suited for me. I am saving a lot of water! I was previously flushing 150ml per drink, 5 times per day. I also almost never make more than two drinks in a row (no guests during lockdown!). So rebound isn’t a big problem. Final thoughts: Small changes in boiler pressure made a much bigger impact on cooling flushes than I expected Next time I can be bothered to open up the machine I might target a 1.25-1.3 pressure as I think this would give me more optionality vs 1.15-1.2. Plus a small flush to heat the cup and clean the shower screen can be helpful. The coffee sensor is fun to play with but didn’t actually cause a change in my routine. My old routine of just flushing to stop flash boiling (plus a second more), then grind/tamp, then brew, turned out to be OK. However, it is helpful to know when your machine is ready to go. Question – is PSTAT drift a thing? I’m sure some of you will comment that my original pressure of 1.45-1.5 is particularly high. I’m sure it was originally a tad lower, perhaps 1.4-1.45 but seemed to have drifted up over the course of a year.
  10. I realised the current lockhills differs from what was originally shown in this thread. It's now 26mg/l of Ca for example (rather than 20). Is this 'updated' version still OK and espresso machine safe? Sent from my SM-G975F using Tapatalk
  11. How did you get on pulling some shots? I have the same machine and it cycles 1.5 to 1.35. This is how it came. At one point I opened up the machine and reduced it slightly. The cycle was perhaps 0.1 lower. But it seems to have drifted back up. After a long idle I need to flush 100ml to stop boiling. I've ordered a coffee sensor so will let you know if that shows anything interesting. Sent from my SM-G975F using Tapatalk
  12. Understood. I think I've realised a fundamental misunderstanding of the machine that led to my earlier question. I thought there was a seperate water circuit used to to warm the group rather than water cycling back through the HX. This meant I imagined a very simple system where water went straight from the tank to the HX to the coffee only when the pump was on. Hence I imagined a fixed volume of water 'sitting still' in the HX tube becoming superheated. In reality I think the water cycles through the system and this means that when the pump starts you are also mixing super heated water with tank water. I can see how this makes the whole thing more complex to model! Does that make sense? Sent from my SM-G975F using Tapatalk
  13. Wow thanks Dave. That was very interesting. Do you or anyone have any good links to explanations of the hx system used by ECM (this machine in particular is even better). I'd be interested now in learning more about the engineering (than the very high level HX graphics you see) In terms of the tests you describe. I think I'd need to invest in a Coffee Sensor for the group head to do that level of testing. Maybe a project for Jan! Sent from my SM-G975F using Tapatalk
  14. Dave can I ask you a technical question. I've been thinking about flushes and wondered if the flush volume will always be the same regardless of boiler pressure? Isn't the volume of water sitting in the heat exchanger always the same and it will always super heat eventually. This might mean the flush volume after a short wait will be different and different boiler temps. But would reach an equilibrium eventually. Sent from my SM-G975F using Tapatalk
  15. Thank you! Sent from my SM-G975F using Tapatalk
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