Hi folks...
As originator of the thread, I want to just do a short update.

First of all thanks for all the science, past posts, and other informative info, and the best things which I've gleaned from all this have been a reminder to diffuse the heat from the group by preflushing the group till the water stops dancing before shots, and let me tell you, my shots the past few days are amazing.

The crema still bubbles out profusely, and explodes/collapses, but I'm drawing that off the shot before using it anyway, and our espresso, macchiatos, cappuccinos, and lattes have just been amazing since I started flushing longer. Sure uses more water, but it's worth it in the shot.

I am excited now to receive our new roaster (switching from air roast to drum) to see if that will add some additional depth to the shots.

Merry Christmas and thank you everyone...I think my own answer to my original question is "Even though adjustments are needed to account for differences brought on by high altitude, it is simple to make those adjustments and pull consistently great shots."

Address7 wrote:My shots generally turn out pretty well, with good visuals, plenty of crema and good flavor. I buy coffee from Jon's (Regulator Johnson, Caffe'd Bolla) often, and although my shots pulled with his coffee are not the same as in his shop, they are still very good (sometimes excellent - but that is up to me)

Jon is a great guy, and he can pull a nice shot himself... however, he was the owner of Bevalo.
caffe d'bolla is the offspring of my demented brain.

Boiling point here in Salt Lake City is roughly 204.1. Chris made it simple with "avoid high temp espressos" If I try to brew Vivace here or something like Malabar Gold, I'll be hard pressed to have the temp stay stable or even reach that high of temp. For higher elevations I recommend espressos tuned for about 197-200 F.

... I also adjust my roasting profile to account for elevation, but that's a continuous work in progress.

hey thanks john.

jon

Jon is a great guy, and he can pull a nice shot himself... however, he was the owner of Bevalo.
caffe d'bolla is the offspring of my demented brain.

John and Jon - my sincere apologies. My fault for not realizing there might be more than one person named John (Jon) in Salt Lake City who cares about espresso.

Jon, hope to meet you at Snowbird sometime - I hit Regulator Johnson yesterday - pretty good, we still need more snow.

John - I'll be back in for more fresh roasted coffee and some nice tea soon.

Cheers, James

Ken Fox wrote:Altimeters, of course, need to be calibrated in order to give accurate results, and they are normally calibrated with the atmospheric pressure.

They're normally calibrated from the closest METAR reports the pilot can receive ( via radio ) , which are generated in turn by a weather observation centre that has a known altitude.

Unless you're quite far from the observation station, it's unlikely that the air mass and subsequent normalized pressure will change too much with the distance. There's not much chicken and egg, the altitude of the METAR broadcast is know with traditional surveying ( ie, not atmospheric pressure )