Archive for March, 2005

Posted on March 31, 2005 - by deCadmus

Tasting: Fair Trade Organic Nicaraguan Matagalpa

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I’ve been tremendously impressed by coffees from Nicaragua these past many months. They are proving yin to the yang of the light, bright fruity notes of what’s become the archetype of Central and South American beans. Nicaragua offers a balancing opposite rooted in darker, earthier and more rustic notes. (more…)

Posted on March 30, 2005 - by deCadmus

A Brave New Experiment

One of the perks [perks, get it?] of working for a coffee company is — surprise — free coffee! And being the coffee-slurping fiend that I am I take full advantage. I have tasted my way from one end of Green Mountain’s coffee line-up to the other and back again… no small task as there are about a hundred different origins and blends to choose from.

Most days I’ll taste something from Africa, and something from the Americas, and something from Indonesia. The operative word here is taste… I don’t formally cup coffees every day. When I want to study a coffee more closely I’ll cup it alongside some of it’s neighbors… a blind line-up of Peru and Colombia, for example, or Tanzania and Kenya. In the process I’ve not only learned more about coffee, I’ve learned quite a lot about our coffee and its lexicon of flavors.

Chances are pretty good I could pick Green Mountain’s coffee out of a line-up that included several other roasters’ beans. That’s not to suggest that our coffees are head-and-shoulders above the crowd, or even so very distinctive… they are, however, very familiar to me by now. I call that a testament to our coffee team’s ability to deliver remarkable consistency crop to crop and roast to roast… something I rarely, if ever, manage to achieve when roasting my own coffee.

Of course, one of the factors that started me down the garden path of roasting my own coffee was a rich appreciation for the sheer diversity of coffee’s sensory qualities from origin to origin. And now that I’m finding our own coffees so familiar, I can’t resist the siren song of other roasters’ coffees and the opportunity to discover something altogether new.

And so begins a brave new experiment.

I’ve ordered a number of coffees from GreatCoffee.com. Each of them has been very highly rated by Kenneth Davids, editor of Coffee Review, and among the who’s who of coffee tasters. My objective isn’t to compare them to Green Mountain’s coffees [I don't know that I could approach that task altogether unbiased - and even if I could, I don't know that you would have reason to believe I succeeded.]

Instead I’ll look to evaluate each coffee on its own merits… and compare and contrast my own take on the coffee at-hand with those of Ken Davids, himself. His cupping style, like my own, is less technical and more experiential. I won’t be referring much to SCAA’s flavor wheels or Agtron charts, and I absolutely won’t be trying to score a coffee on a 100 point scale.

Stay tuned… and let’s see what happens.

Posted on March 28, 2005 - by deCadmus

Ich bin ein Vermonter

Finally! For fellow flatlanders who have made the move to Vermont, a little help with the local language…

Faam: A place where you raise animals and vegetables.

Baan: A structure on the faam.

Jaw on dare: The green tractor in the baan.

Soda: What a farmer did to his prized cow to help pay for his new jaw on dare.

Posted on March 27, 2005 - by deCadmus

It’s a tiny, connected world…

A few days ago I posted a brief link to a Flikr photo set… a gallery of fab latte art. Turns out that the shutterbug — Tonx — is also a coffee roaster, barista and resident web guy at Victrola Coffee in Seattle, as well as a fellow coffee blogger.

Read his beverage manifesto. Send it to friends. Post it on the walls of vendors of supersized coffee milkshakes near you…

I think a trip to Victrola will be on my agenda in Seattle next month.

Posted on March 27, 2005 - by deCadmus

Beverage Containment Device

My inner geek mightily covets this tech-lookin’ travel tumbler…

20 ounce double-walled plastic transparent travel mug with removable top and a futuristic binary imprint on it. The binary, when translated, reveals its ascii equivalent of ‘beverage containment device’.

Brought to you by — of course — ThinkGeek.

Posted on March 24, 2005 - by deCadmus

The Senseo Crema Mystery

The Mystery: What’s up with the Senseo, Anyway?

The machine produced by Philips and Douwe Egberts has been rather aggressively marketed as the “coffee machine with the delicious crema layer”. I have been asked more times than I can count [and I count fairly well... rarely even have to take off my socks] with questions like,

a) is this espresso? b) is it really crema? c) if it’s not crema, what is it? and, d) how does the Senseo make that stuff?

The answers:

Is it espresso? Don’t be silly. ;)

Is it really crema? No. Crema is… well, let’s defer to Dr. Illy:

“Crema, the dense, reddish-brown foam that tops an espresso, is composed mainly of tiny carbon dioxide and water vapor bubbles surrounded by surfactant films. The crema also includes emulsified oils containing key aromatic compounds and dark fragments of the coffee bean cell structure.”

The foam produced by a Senseo is *not* an emulsion; the coffee in the Senseo pod [or pad] is not ground fine enough, nor is the pressure in its brewing great enough to release the non-water soluble oils and lipids to create such an emulsion… and those few oils that *might* be released would be trapped in the filter material of the coffee pod itself. [This is confirmed in left-handed fashion by Philips/Douwe's FAQ: "The SENSEO coffee brewing process is very efficient leaving hardly any oil in the brew."]

Further, it’s unlikely that the coffee found in a Senseo pod is fresh enough, or been packaged well enough that the delicate aromatic compounds, or even carbon dioxide — both such an important part an espresso’s crema — remain.

So what is this stuff? It’s *foam*. Bubbles. Mostly air bubbles, and water vapor, and probably some CO2, encapsulated by the brewed coffee solution. Again, it’s not emulsified oils.

There are a number of compounds in coffee that make lovely bubbles… long, complex protein chains that have some remarkable [even improbable] properties, surface tension being only one of them. [The physics of coffee rings is a story for another day.]

So how’s the Senseo make that foam? Well, this is where the Senseo’s designers got pretty clever!

At the bottom of the pod carrier [a little tray that holds either one or two pods... think of it as a device-specific coffee basket and portafilter if you like] is a barrel-shaped nozzle. Embedded in that nozzle is a small metal disk. This disk has a very small orifice or aperture at its center… 1mm, maybe 1.5mm in size.

While brewing, the machine’s pump pushes water through this assembly under pressure… we’re not talking espresso-like pressure here, just something on the order of 1.5 to 2 times atmosphere, or 1.5 to 2 bars [by way of reference, espresso is brewed at 9 bars].

Here’s where some junior-varsity physics comes in…

One of the interesting properties of fluids is that, when under pressure and presented with a wee, little aperture as a way to escape, the fluid will first form a little vortex or funnel above the orifice itself, trapping anything that’s *not* a fluid [air, water vapor, CO2, etc.] in its center. For an example of this, look no further than your bathtub… pull the plug on a tub full of water and watch the vortices spin. And listen to the sucking sound as air is trapped in the vortex.

When the pressurized fluid [and its trapped gasses] emerges on the *other* side of the wee, little aperture and is suddenly no longer under pressure, the gasses are *encapsulated* by the fluid in a series of amazingly uniform bubbles. The size of these bubbles can be regulated by varying the amount of pressure, or the size of the orifice, or the surface tension of the fluid solution itself. So, if you want your bubbles to be *extremely* tiny [as you would for, say, an ink-jet printer - which uses this very same principle of fluids] then the aperture would be tiny, indeed.

In the case of the Senseo brewer, then, the designers tuned the size of the orifice to the typical surface tension of brewed coffee and to the amount of pressure delivered by the pump and lo… bubbles. Lots and lots of bubbles. And lots and lots of bubbles is foam… it’s still not crema.

So there you are.

As an interesting aside, I think the fluid dynamics at play here have some interesting implications for why espresso brewed with a bottomless portafilter seems to have a more textural quality to it… but that, too, is a story for another day.

My thanks to Don Holly and Lindsey Bolger who let me tinker with a Senseo in the coffee lab, and to Don especially for sharing my enthusiasm for discovering how things work by destroying them. ;)

Posted on March 17, 2005 - by deCadmus

Latte art photoset on Flickr

A very spiffy latte art gallery. Some excellent technique here.