chopinhauer wrote:Oh, and one more question. I know where the p-stat is on the cremina, but which way does one turn the round dial in order to turn the pressure down? Looking at the back of the machine, to the left? or to the right?

My apologies to whoever had the page I lifted this pic from. Copied it to my hard drive ages ago and can't remember who the original poster was.
Jon

Thanks, well that pic certainly answers my query in the CLEAREST possible way. Thanks for pointing it out to me.

chopinhauer wrote:Well after switching to a 1973 cremina 67 a month ago I have encountered a fairly steep adjustment curve, especially when it comes to steaming small quantities of milk. It is much harder to do this without burning the milk because the increased steaming power of my cremina. What you write prompts me to think that perhaps I might have more success by turning the p-stat down to decrease the steam power. Is that a correct assumption?

Yes, lowering the p-stat does reduce the force of the steam, making the process more forgiving when smaller quantities of milk are involved.

chopinhauer wrote:If I do turn it down then how low can I go before affecting the pressure for the purposes of making coffee? For, as you know, the cremina 67s don't have pressure gauges therefore one has to do adjust the p-stat by trial and error.

How low you set the p-stat is partly driven by personal taste. I have had a great cup of espresso with a Terroir roast at 195°F and like to have my p-stat set so that at the bottom of the heat cycle, I can get temps in that cooler range. According to the steam tables, boiler water temperature at .7 bar is ~194°F. At .8 bar it is 200°F. At .9 bar it is 206°F [though these temps need to be adjusted for atmospheric pressure and the attentuating effects of the group: 1.7 bar is 239F; 1.8 is 242.5F; 1.9 is 245.5F in the boiler.]

You can rig up a pressure gauge temporarily to do this calibration -- there is a picture on the H-B website that Steve Robinson posted a year or more ago. For best results, follow his approach and not the quick-and-dirty approach where you attach the gauge to the steam outlet. You will need an adapting coupler in either case, to go from the NPT thread on the gauge to the thread on the machine.

Regards
Timo

P.S. Olympia used to have a (pricey ) pressure-gauge boiler cap combo but I cannot find the part at the moment on their website.

timo888 wrote:You can rig up a pressure gauge temporarily to do this calibration -- there is a picture on the H-B website that Steve Robinson posted a year or more ago. For best results, follow his approach and not the quick-and-dirty approach where you attach the gauge to the steam outlet.

Just curious, any reason for recommending one method over the other?
Jon

If you attach the gauge to the boiler, you can bleed off the 'false pressure' using the steam wand, and you can test the steam at the chosen p-stat setting more easily.
Regards
Timo

Seems to me you could lift the lever up and relieve the false pressure that way, no?

The lever draws water to the group via a tube which extends all the way down to just above the heating element at the base of the boiler. The air would remain trapped at the top of the boiler.

Regards
Timo

timo888 wrote:If you attach the gauge to the boiler, you can bleed off the 'false pressure' using the steam wand, and you can test the steam at the chosen p-stat setting more easily.
Regards
Timo

srobinson wrote:Actually Dan and I just did a pressure test on the machine a couple weeks ago. The Cremina 67 does not have a pressure gauge on it but we were able to hook one up right off the top of the boiler.

There is a thumbwheel at the base of the pressurestat that allows you to adjust. I have decided to keep mine at 1.1-1.2

We found that the machine is very stable with its pressure. We did a couple tests to see how much pressure fluctuated between cycles and it all stayed within a .1 range. At the range we picked you get great steam and solid pressure for your pulls.

I think this is the picture you're referring to from Restoration of an Olympia Cremina thread. Am I missing something or are you referring to another project?
Jon

I remember seeing a pressure gauge hookup where the steam wand was still operable, but perhaps I am conflating more than one memory, Steve Robinson's pictorial essay with another. But in any case, if you don't release the false pressure your reading could be off, though I don't know by how much--the difference could be negligible.
Regards
Timo

roadman wrote:<image>
My apologies to whoever had the page I lifted this pic from. Copied it to my hard drive ages ago and can't remember who the original poster was.
Jon

Actually this is a picture from the resources section of my website FreshCoffeeShop.

No apologies needed

I own an Olympia Cremina 67 for one year and I've written about my experience and some tips in a quite lengthy article (where this photo is located)

Lowering the pressurestat and blocking two of the steam wand's holes has worked best for me.

I would like to also recommend using the OKS 1110 as a lubricant for the group.

Friendly Regards
Karolos Tsiligirian