kiboker wrote:If it is the water temp, is that adjustable?

Yes, I believe the Model M Bar has a standard Sirai pressurestat. See pg 30 of the manual: http://www.lapavoni.com/wp-content/uplo ... an_bar.pdf

To run the same boiler temperature at 2000 meters that you were accustomed to at sea level will require running at a boiler gauge pressure that is appx 0.2 bar higher than what you ran at sea level.*

However, be aware that there is a variety of opinion on the effect of altitude, and some would argue that you may want to run at a lower boiler temp (not re-adjust the pStat) and avoid coffees that are optimal at high temps.

* At sea level, the ambient pressure is about 1.01 bar. At 2000 meters it is only about .795 bar. So you need to run your machine's gauge pressure about 0.215 bar higher to have the same absolute pressure as you had at sea level , and it is the absolute pressure that determines your boiler temperature.

RapidCoffee wrote:14g coffee dose and 40g extracted liquid gives a brew ratio of 35%. Like it or not, that is a lungo.


Are you getting any crema in your extractions? An espresso shot should extract as virtually 100% crema (from a pump machine). Crema has roughly half the density of water, so 2oz volume of crema weighs about 28g (and 1 oz weighs only 14g). If your extractions have the same density as water, something has gone badly wrong.

I'm not here for a debate, but lungo is Italian for "long". A long espresso is, principally, defined by the volume of additional water. That is not my case. As I am trying to clearly explain, I am pulling normale length shots, 1 fl oz per. It has a fairly full body of crema, pulling 26-30 seconds, weighing in at 40 something grams, and missing the key aspects in the body of the espresso. I can get most of that body back but only with stopping it at the 1/2 shot range.

So, to summarise, I am asking for advice, not a semantics argument.
A lungo is defined by volume, extraction is the byproduct
2 oz of water weighs 60 grams not 40, so it doesn't have the same density by an amount of 50%
And I stated from the beginning that something was wrong, so that should have been obvious.

homeburrero wrote:Yes, I believe the Model M Bar has a standard Sirai pressurestat. See pg 30 of the manual: http://www.lapavoni.com/wp-content/uplo ... an_bar.pdf

To run the same boiler temperature at 2000 meters that you were accustomed to at sea level will require running at a boiler gauge pressure that is appx 0.2 bar higher than what you ran at sea level.*

However, be aware that there is a variety of opinion on the effect of altitude, and some would argue that you may want to run at a lower boiler temp (not re-adjust the pStat) and avoid coffees that are optimal at high temps.

* At sea level, the ambient pressure is about 1.01 bar. At 2000 meters it is only about .795 bar. So you need to run your machine's gauge pressure about 0.215 bar higher to have the same absolute pressure as you had at sea level , and it is the absolute pressure that determines your boiler temperature.

Thank you for the constructive input!

But, just to make sure I am not confusing anything, the pressure stat would be separate from the temp? because while it's lower pressure here, water boils at a lower temp as well. As I said, I just want to make sure I have that right.

kiboker wrote:But, just to make sure I am not confusing anything, the pressure stat would be separate from the temp?

The pressurestat controls both the temperature and the pressure. They are directly related - given the absolute pressure you can predict the temperature - and that's the basis for using pressurestats in espresso machines to control temperature.

kiboker wrote:because while it's lower pressure here, water boils at a lower temp as well.

Yes. Same principle applies. In an open container, lower ambient pressure => lower boiling point.

Key point that confuses many folks is the fact that the pressurestat and the pressure gauges on espresso machines measure gauge pressure, which is equal to the absolute pressure minus the ambient pressure. So if you move the machine up to higher elevations you have to increase the gauge pressure setting a bit to make up for the lower ambient pressure if you want to keep the same boiler temperature.

homeburrero wrote:The pressurestat controls both the temperature and the pressure. They are directly related - given the absolute pressure you can predict the temperature - and that's the basis for using pressurestats in espresso machines to control temperature.

Yes. Same principle applies. In an open container, lower ambient pressure => lower boiling point.

Key point that confuses many folks is the fact that the pressurestat and the pressure gauges on espresso machines measure gauge pressure, which is equal to the absolute pressure minus the ambient pressure. So if you move the machine up to higher elevations you have to increase the gauge pressure setting a bit to make up for the lower ambient pressure if you want to keep the same boiler temperature.

Thank you for clarifying. However I didnt see anything on how to adjust it. Any suggestions?

kiboker wrote:However I didnt see anything on how to adjust it. Any suggestions?

On pg 30 of the pdf manual that I linked above, you should see this:


What pressure do you have now at the peak of the pressure cycle? If it's already above 1.3 bar I wouldn't advise increasing it.

Also, after adjusting, or whenever this machine first powers up, be sure to follow the advice in the manual to open the steam wand and release a few seconds of steam. Otherwise there may be air in the boiler which will cause it to reach full pressure at an abnormally low temperature. (The ill-named 'false pressure' effect.) After blowing off the air in the boiler you need to give the machine 35-45 minutes for everything to come up to full temp.

I'm not here for a debate, but lungo is Italian for "long". A long espresso is, principally, defined by the volume of additional water. That is not my case. As I am trying to clearly explain, I am pulling normale length shots, 1 fl oz per. It has a fairly full body of crema, pulling 26-30 seconds, weighing in at 40 something grams, and missing the key aspects in the body of the espresso. I can get most of that body back but only with stopping it at the 1/2 shot range.

So, to summarise, I am asking for advice, not a semantics argument.
A lungo is defined by volume, extraction is the byproduct
2 oz of water weighs 60 grams not 40, so it doesn't have the same density by an amount of 50%
And I stated from the beginning that something was wrong, so that should have been obvious.

I wouldn't be too quick to dismiss John's comments as "semantics argument". What I think he was merely implying is that volume basis is not a useful way of defining a shot of espresso, whereas weight basis is. 40-plus grams out of a 14 gram dose is a diluted drink, regardless the volume.
The volumetric definition of a 2 fl. oz double shot holds true for most Italian style crema-rich coffee blends, but is not applicable to just any coffee and apparently to all extraction conditions. In your case, you observed that your desired 28 grams took up 60 ml of volume at sea level and only half that volume at 2000 m altitude. This suggests that, all else assumed being equal, either less crema develops or it dissipates much faster, even while you are brewing the shot. Can this be attributed to the altitude? Theoretically maybe so, but the difference in ambient pressure between sea level and 2000 m above is small compared to the 9 bar gauge pressure at which the volatile components of the coffee that contribute to the crema dissolve, so I would not expect such a large difference in volume. Perhaps it is related to the water you are using.

Having said this, I personally don't weigh every shot I pull, but for a ball park check I occasionally pull a double into a shot glass with a marking at 30 ml. At say a 15-16 grams dose I let the crema dissipate until there is a clear interface. The liquid below that interface has a density close to that of water, so it should measure just about 30 ml (or 1 fl. oz).

I agree completely with both John and Bert here. When you go with a normale brew ratio (14g in and 28g out) but are getting only about 28ml of volume, you must be getting shots with zero crema. Your customers may not like the low volume, and I would think be even more disappointed with the appearance of that lack of crema.

I also agree that your problem is probably not related to altitude - 2000 meters isn't that high, and in fact as you get higher (Bogota or Quito) the usual observation is that you get tons of crema but it may have large bubbles, and dissipates more quickly than expected. Some have addressed this by giving their coffees a little more rest post-roast:

Barometric Pressure at Altitude
Espresso at altitude - Could use some theory

kiboker wrote:So, to summarise, I am asking for advice, not a semantics argument.

Looking at this from the outside, to me it seems that you were given advice but you turned it into a semantics argument.

Myself, I wouldn't look towards Italy if I wanted good espresso. Unfortunately they haven't updated their methods in at least about half a century. The rest of the world have. The third wave coffee movement defines ristretto, normale and lungo by the ratio not by volume. It makes a lot more sense if you think about it thoroughly.

Scott Rao wrote a good book about espresso The Professional Barista's Handbook. It is essential read for anyone serious with espresso.
http://www.scottrao.com

Nick Name wrote:Looking at this from the outside, to me it seems that you were given advice but you turned it into a semantics argument.

Myself, I wouldn't look towards Italy if I wanted good espressos. Unfortunately they haven't updated their methods in at least about half a century. The rest of the world have. The third wave coffee movement defines ristretto, normale and lungo by the ratio not by volume. It makes a lot more sense if you think about it thoroughly.

Scott Rao wrote a good book about espresso The Professional Barista's Handbook. It is essential read for anyone serious with espresso.
http://www.scottrao.com

I don't know if you saw but there was no advice given. I get a good amount of crema, not heavily bubbled, it's hardly alonge flavor.

I am trying to be clear in stating that it's not the taste or appearance of lungo or watered down heavily but it has a fairly good appearance, and some taste, but lacking the principal body. Altitude was only a speculation but the persistence of "diagnosing" it as lungo is neither accurate, along with his other observations, nor productive. Hence my statement. Lungo is defined by volume, I am asking for insights into the brewing process or fixes. If you have advice on machine settings, roasting, rest age, grind or combination of, I am asking for it. If you're fixating on telling me what it isn't and dont have a tip, why post a response?


As for homeburrero, sorry about that! For some reason it shows up on a different page for me. Thank you!!!