Anyone have experience dealing with altitude and brewing coffee?
One of the apprentices at Intelli LA was curious how to deal with water that boils at 196 degrees.
Do you simply ignore the boiling and take the temp up to 200 or so?
If I recall correctly, you cannot take water past its boiling point unless you involve a pressure cooker. This is why you can use a volume of boiling water to calibrate thermometers... at a full boil (at sea level) it will always be 212 DegF.
(Heads to the kitchen to try it himself, so as not to look like a complete ass for too long).
at nine bars, you have a pressure cooker. and water won't still be at 200 degrees after passing through a cake of coffee grounds, so there's no reason to worry about it boiling in the demitasse.
and you'd better not use tap water to calibrate your thermometers at sea level; impurities change the boiling point.
being as crema is a product of the pressure difference between the basket where CO2 is being dissolved and the atmosphere it is being poured out into, it would stand to reason that one would have greater volume of crema at higher altitudes. anybody ever observed something like this happening?
what happens if you turn your hot water tower to 200? does it sputter when it dispenses? is enough heat lost by the time that it reaches the spout that it's below boiling point?
i was once playing on a clover with a yirg from conscious coffee. at 204, it tasted like any other good yirg. lemony. big surprise. but when i cranked it down to 200, it exploded with amazing berry flavors and a super buttery mouthfeel. when i told the roaster, nolan, this he said that my observation makes perfect sense because, in boulder, water boils at 198 so they roast with lower brewing temperatures in mind.
you could probably make up for the difference by preheating the pour-over cones more, if they're porcelain. if that's not possible, possibly give it a little bit of a gentle stir and maybe tighten up the grind to make up for the lower temp.
long story short (if i understood correctly): it sounds like espresso comes out super bubbly and the crema is basically bursting before it hits the cup. he brought up a very interesting idea though:
" I don't have a solution for the Denver Effect. It would appear that
supergourmet espresso exists up to maybe 3,000 feet elevation.
Above that you better get a French Press. (Perhaps removing the
oxygen from your brewing water before it enters your espresso
machine would be an option, but that would have a pronounced
effect on flavor, I think? What do you think?) "
Clearly, different coffees require different temperatures.
The roast profile has an effect on this as well. There is no "solution", per say. There are only hacks to try to make due with 195F water (who are we kidding, if the max is 196, there's no way it'll extract at 196.. even 195 is extremely generous).
Factors of extraction are easy enough to list:
Temperature (or energy)
Grind particle size (or surface area)
The problem is that different components are extracted at different solving energies (water temperatures), so even grinding finer or brewing longer will not result in a full extraction, however, this is not to say that the resulting cup wouldn't be good.
I don't live in Denver, but I do live at 3,241ft, and I tend to favor finer grinds in every brew method. The result of altitude(and by extension, a lower boiling point(208F-)? It's possible.
Schomer did a lot for specialty coffee, but he doesn't know everything, and it can't be totally hopeless, or coffee in Denver would be terrible no matter where you went!
I have a friend who opened a shop in Salt Lake City not long ago, at an altitude of 4,226 FT, and I don't think they've really had much issue. They're about 1Kft. higher than me, and 1Kft. lower than Denver, so that may or may not mean anything.
Keeping the temperature up is obviously a critical measure in such a situation. That having been said, I would probably void methods that sap extractive energy before coffee contact such as Melitta, Chemex, (or any other pour-over, for that matter) and probably favor things that keep the heat as high as possible by keeping the energetic mass contained together (Press, vac-pot, or any other full-submersion brewing) along with any insulative elements I could get my paws on (neoprene french press insulators, vacuum insulated french presses, still ambient air, etc..).
I'm not saying "this is what I've found to be true" or anything like that. I'm just telling you what I would do if I found myself in that situation. I'd try to make it work as best I could. If it doesn't work, move on to something else until we've come to the lesser of evils, if a solution is never discovered, and do the best we can with that.
though I don't brew at high altitudes, your question has intigued me further, so I've been doing a little research. Here's a stab at it. If temperature is a measure of energy and extraction is directly affected by the energy because of its frequency of interaction with the coffee, then obviously temperature is just a measure of how much the coffee and the water interact in any given time. If we take away things that restrict the interactions (i.e. atmospheric pressure), then the frequency can occur with less resistance. I would assume that conductivity of the atmosphere plays into the extraction. just like using copper to pass electricity changes resistance of the energy flow versus using steel.
All of this long-windedness to say that, based on my research, a similar extraction can be achieved at lower temperatures due to the lowered resistance in atmospheric pressure.
That's a nice theory, but it unfortunately does not hold up in practice.
I spent a week snowboarding at Angel Fire (Base elevation: 8,382ft) a year or two ago, and pretty well gave up on getting a complete extraction. Energy is directly related not only to the RATE of extraction, but also to WHAT gets extracted.
No need to be offended. Seemed like it was getting nerdy like I like it. And yes, it was put back on track finally. I like it when it gets real technical like this. Reminds me how much I don't know. Brady and I get together sometimes, and the guy is so over my head, he's in the clouds, but it makes me have to learn new things, and understand things in a different way. And that my friends, is a good thing.
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