Weather's effect on espresso

[cdh]

The past few weeks in Pennsylvania have had quite a variety of weather, and on a particularly overcast morning when a low pressure zone was sitting on top of me, I noticed that my espresso turned out particularly delicious. The crema was thicker, there was more body, etc.

I've since been paying a little attention to the correlation between the weather and the quality of the espresso I pull myself each morning. I think I have half decent control over the other variables like bean, grind and tamp... and I think there are differences from day to day.

That observation, combined with my understanding that Seattle is often overcast and rainy, and is the world capital for high quality espresso made me wonder what, if any relation anybody else has observed.

I'm almost tempted to put a barometer next to my espresso machine and take notes... if only there were an objective and quantitative method of describing the quality of the espresso.

A neat thought, anyway... I'd love to hear ideas for experiments that might disprove this hypothesis.

Edited September 11, 2004 by cdh (log)

[slkinsey]

Interesting observation! What we really need is a good espresso machine and one of those pressure chambers they use for deep sea divers. Hmmmmm....

[melkor]

More humid weather needs a slightly more coarse ground coffee for perfect shots, I suspect if you set your grinder slightly finer on clear/dry days you'll get the same quality espresso you get on overcast/humid days now.

[phaelon56]

Yes.... if you eliminate the variables (i.e. you have consistent tamp pressure, brewing temp, cleanliness, always strive to achieve the same shot volume, use beans of known qualities etc), the one thing remaining to be done is maintain the ideal brewing time of 22 to 27 seconds (or a trifle longer on some E61 machines where pre-infusion adds to the overall time). Maintaining the desired result is achieved by adjusting grind - if all else continues ot be done correctly on the grind needs to be adjusted . In a busy shop that's following proper procedure and actively monitoring the pull time of their shots, weather fluctuations may prompt a need to adjust the grinder setting many times in a day. In places where humidity fluctuates wildly the grind may sometimes neede to be adjusted on an hourly basis. (Syracuse, where I live, fluctuates as much as Seattle does in this regard except during our long artificial heating season).

[BeJam]

More humid weather needs a slightly more coarse ground coffee for perfect shots, I suspect if you set your grinder slightly finer on clear/dry days you'll get the same quality espresso you get on overcast/humid days now.

←

As I made my way downstairs this morning for nice espresso, I remembered this thread and was wondering why a coarser grind on humid days? It's a perfect day here in Dearborn, but the crema's been a little thin lately.

I also wonder that maybe bad weather makes espresso and coffee just taste better because the day is so crappy and good coffee is just the right thing to have, like having a good bowl of soup on cold day in November.

[malachi]

High humidity, moderate temps and low pressure, in my experience, make it easier to pull consistently good shots.

In other words, they don't make the shots better - they just make it more likely that your shots will be good.

Of course, the reality is that, because coffee is hygroscopic, very humid conditions result in coffee actually absorbing moisture from the air (rather than losing it). This results in coffee that can pack tighter and will result in slower extraction. In many cases, this can cover poor distribution and tamping technique and can extend the "sweet spot" of a shot.

Low humidity is the enemy of coffee - causing it to stale quickly.

High temps are also the enemy for the same reason.

Finally, direct sun is the enemy as well.

So... high humidity, medium temps and overcast skies are our friends!

[Kyle_Larson]

That's what I love about Seattle.