HX Heaven or 1½ Boiler

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cafeIKE

#1: Post by cafeIKE »

About 18 months ago I added a PID to my Vibiemme Domobar Super.
It's great. I can pull shots without any flushing.

As there's never a free lunch, steaming capability is non-existant at 0.5bar and its a PITA to run the PID set point up and down like a YoYo.

To solve the problem, I added a small 12v DC power supply controlled by the pStat.

The 12v connects to one side of a SPDT toggle switch and the PID output to the other.
The common terminal connects to the SSR input.

When I need steam, I just flip the switch and the boiler quickly runs up to 1.3bar, providing ample steam. At a recent dinner party, I was able to make 3 lattes and a cappa, all doubles, in under 6 minutes.

When I'm done steaming, just flip the switch back and the boiler idles at perfect shot pulling temperature.

seattlesetters

#2: Post by seattlesetters »

That's a very elegant solution, Ian. Nice work!

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GC7
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#3: Post by GC7 »

cafeIKE wrote:About 18 months ago I added a PID to my Vibiemme Domobar Super.
It's great. I can pull shots without any flushing.

As there's never a free lunch, steaming capability is non-existant at 0.5bar and its a PITA to run the PID set point up and down like a YoYo.

To solve the problem, I added a small 12v DC power supply controlled by the pStat.

The 12v connects to one side of a SPDT toggle switch and the PID output to the other.
The common terminal connects to the SSR input.

When I need steam, I just flip the switch and the boiler quickly runs up to 1.3bar, providing ample steam. At a recent dinner party, I was able to make 3 lattes and a cappa, all doubles, in under 6 minutes.

When I'm done steaming, just flip the switch back and the boiler idles at perfect shot pulling temperature.
Sorry to bring up an older thread Ian but I'd really like to know what range of tempratures you set your PID to get good shots without flushing.

I have an Anita with PID and EricS thermometer at the grouphead.

At 211* PID temperature the grouphead at the thermometer reads 178.5* (~33* differential) and when I pull 2-3 oz of water (no flush) the thermometer goes up to the mid 180's and the (preheated with boiling water) glass measures upper 170's using a digital meat thermometer.

At 221* PID the grouphead steady state temp at the thermometer is 188* (33* differential) and when I pull 3 oz of water (again no flush) the grouphead thermometer reaches 196* (briefly and then down to 194) and the cup temperature is 184.5*

At 231* PID (this is right between 0.45 - 0.5 bar on my pressure gauge) the grouphead temp at the thermometer is 196* (~35* differential) and when I pull 3 oz of water (again no flush) the grouphead thermometer reaches 206* (briefly and then down to 203*) and the cup temperature is 190* This seems reasonable.

At 245* where I have the PID set normally and I use Eric's flushing recommendations the steady state grouphead temperature is 209.5* (about 36* differential)

I know that I need to get a brew temperature between 197* to 203* or so but I'd love to hear what works for others to get great coffee and I'd be curious to see what my numbers correspond to with regard to actual or approximate brew temperatures in the above simulated shots. I was told to try 211* but this does not yield good tasting espresso and my numbers above seem to indicate too cool brewing). Am I correct here?

Many thanks in advance.

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erics
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#4: Post by erics »

Geoffrey -

Firstly, where are you in NY - NYC? - as I certainly get up there every once in a while. Also, there are always updates to the manual for the digital thermometer at: http://users.rcn.com/erics/

I ASSUME you are trying to operate Anita with no cooling flush and your drink of choice is a straight espresso between 1.50 and 1.75 ounces. With that in mind, your 3 ounce flush is really a screen cleansing operation and should take place immediately AFTER you brew your shot, NOT prior to brewing a shot. Adjust your PID such that group temp reads 198-199F and try some shots there. It will take maybe 30 minutes to stabilize at any new temp and probably 10-15 minutes between shots.

Can you provide some pics/details of your PID installation?
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at rcn dot com

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GC7
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#5: Post by GC7 »

Eric

Many thanks for the response. Yes - I work in NYC and live just to the North in Westchester County.

I can get some photos by tomorrow but the PID is from Dave and says Delta on the upper left.

I am new to espresso so I am trying to get my techniques down and see what gives me the best results and closest to those addicting shots I had recently at the Blue Bottle Cafe in SF. I just got a new Compak K3 touch grinder which has helped A LOT. I have been using a 245* boiler temp and using your flush (185) and wait as well as a flush to 200* and go within 10 seconds or so. Both are OK. I would like to just be able to mindlessly pull my morning shot without any of that. I was told to try a 211* setting but that seems to be too cool.

The 3 oz. I mentioned are simply what I guessed would be used to make the shot without any flush so I measured that water with a digital meat thermometer in a preheated espresso glass. I do flush and clean the showerhead after every shot too. Given your statement to get the grouphead to a steady state temperature of 198 then I would need to keep the boiler at about 233-234* or so to pull a shot without any fluch at all. That would be just about the 0.5 bar that Ike quoted in the first post.

PS- Let me know if you will be in NY.

CambodianBeast

#6: Post by CambodianBeast »

Geoffrey,

I have a PID Anita as well, and I love it.

Since you are new to espresso, why not start off with the "standard" HX flush technique before experimenting with lower boiler temps? The temperature stability of HX machines at full temp has been well studied, and this way you can get a good handle on what your current setup can offer - then you can compare the results of low-temp experiments to this "baseline".

I keep my boiler at 254 or 255 F, and use the basic technique suggested here: /hx-love-ma ... ature.html. Basically: Anita warmed up 30 min, coffee ground and dosed, quick cooling flush to ~199 (~7 seconds after the end of sputtering), quick WDT and tamp, and GO.

The "water dance" is often made to seem more complicated than it really is, and after a few weekends of practice it can be as "mindless" as the rest of your morning routine.

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GC7
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#7: Post by GC7 »

Damian

Thanks for the reply. As I mentioned, I have been playing with different methods such as flush and go (your method), Eric's temperature probe flush and recover method and I'd like to try the no flush method for mornings where I just want one or two espresso's before going off to work. I was clearly held back by the Virtuoso grinder . I can see that clearly now that I have a first rate dedicated espresso grinder.

As a scientist I'd like to do some systematic measurements of what works best for my tastes. I am on the way thanks to all the advise I've received from Dave, Mary at Chris' Coffee and the good contributors to this forum.

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cafeIKE

#8: Post by cafeIKE »

GC7 wrote:Sorry to bring up an older thread Ian but I'd really like to know what range of tempratures you set your PID to get good shots without flushing.
No apologies necessary. Sorry about the tardy response. Notifications seem problematic at present.

My normal range of temperatures is 228° to 234°F, for a brew range of ~195° to ~198°F. The group thermometer idles a bit lower than the brew temp and rises above it at the start of the shot.

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GC7
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#9: Post by GC7 »

Many thanks Ian

Your numbers are pretty well in line with how my machine is functioning which is comforting that all is well on my end.

I'll try to pull some shots in that temperature range.

Are you still using the no flush method or have you moved on to something else that is reproducible for you?

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cafeIKE

#10: Post by cafeIKE »

Pretty much No Flush all the time. If I do a bit of steaming for a party, I'll flush a little to keep the group under control.

What are your P I D parameters?