Steering with the throttle

In the middle of an interesting phone conversation with Philip Search, I was trying to find an analogy to help explain a rather obscure aspect of espresso making. I hope it didn't throw him off too much when I came up with the following:

If you're ever done automobile racing, you've experienced the phenomenon of steering with the throttle. When you're in a curve, and your tires are working near their limit of adhesion, you can actually keep the steering wheel fixed and steer the car with the accelerator pedal. It is a revelation to experience this for the first time, because nothing in everyday driving tips you off that it might be possible.

By the way, please don't attempt to learn how to do this without an instructor on a track. Otherwise, you may experience more than you bargained for and, as they say in racing, fail to keep the shiny side up!

OK, so what does this have to do with coffee? Some time ago, I was experimenting with espressos, trying to figure out how preinfusion (or the lack of it) affected the extraction. And I stumbled upon something unexpected.

I had rigged up a series of valves that allowed me to flip back and forth between two extraction scenarios. In one, the initial flow of water to the group was restricted so that the buildup to full 9 bar pressure took about 7-8 seconds. In the other, the initial flow was unrestricted and it took only a second or two to get 9 bars. The difference was roughly like having installed an 0.6mm gicleur (slow buildup) and then switching to a 1.0mm or larger gicleur (fast buildup).

The surprise was that the fast pressure buildup had the same effect on shot timing as if I had used a much finer grind: the shot flowed so slowly from the portafilter that I had to grind more coarsely for subsequent shots. This was the opposite of what I had expected (which was that the faster pressure buildup would result in a shot that took less time).

At the time, Dr. John offered an explanation for why this occurred, and he's probably correct. But the bottom line is, not only does preinfusion lessen the chance that you'll have channeling in the portafilter, it also changes the grind required for your desired shot timing. Exactly how this affects the shot's flavor and texture is a vast subject....

I always thought this was pretty interesting; I hope you do, too. So, kids, be open to new phenomena, experiment with preinfusion in your espresso making, and always keep the shiny side up! :-)

I love this grinder

On the amateur coffee forums, not a day goes by without some poor schlep wondering why their brand new espresso machine gushes out only sickly thin, 15 second shots. And not a day goes by without somebody informing them that a quality espresso grinder is absolutely necessary to make good espresso.

Well, after a couple days of using the new 3 phase Robur instead of my old Mazzer Mini, I gotta paraphrase that nutty Steve Balmer guy: I LOVE this grinder!

The shots are thicker, longer, and tastier than before. The bottomless pours are a visual feast. Those big 83mm burrs, turning at a cool 420 rpm, make a soulful whirring sound as they slice through 17 grams of beans in less than 5 seconds.

This is really fun.

Robur Baron?

Well, they did warn me that a three phase Robur was a bit of overkill for home use. :-)

(To be continued....)

barefoot and coffeeless

There I was, barefoot, coffeeless and naked as a jay bird. I donned my terry cloth robe. Outside, the weather was durie; bad storms put my grinder settings on the fritz and me in a dismas mood. I turned on the ellie but all the programs were trish.

Tucking in my peter, a paul came over me and I felt so grumpy. Not only that, but my klaus of a roommate had nicked my chosen tamper and it wasn't likely that I'd get it bakke. He kent give a skeie about returning stuff and it drives me tacy.

The tamper had cost a fortune but I really doug the tony heather-colored handle (somewhere between amber and bronwen). It felt taylor made to phil my hand. My search to diserna difference in the shots with the new tamper was riddled with doubt. But to denye myself the purchase would have been like a staub in the heart even though I couldn't really aford it.

I was rather...duh...furious at that hasbeen roommate for using the last of my coffee, too. Mark my words, he's jenuinely no prince. The anger made me a little less intelligent and a lot more daryn; I didn't care a gay minute what he might do. I found his secret coffee stash, but I didn't have the kees. So I had to jimmy open the lock and phoung open the door.

Although stealing goes counter to my culture, I was hungry as a bassett hound and stubborn as a billy goat. Without caffeine, my willpower was scace and I became a sl28ave to habit. "I ain't owen that roommate nothin', just gimme some joe," screamed the thoughts eccoing in my head. Marshalling my energies, I brewed a cup justin time, hoping it would be the ultimo.

But ono! the machine didn't have enough watts. The brew looked murky and tasted rather kyle. I let it flow down the duane into the black well. Mike my words, some day I'll get it white.

Less is More

An excellent blog by Douglas Takeshi Wolfe helped to clarify some thoughts I've had about the current espresso scene. Despite our lofty pretensions, there is, in my opinion, a bit of uncomfortable similarity between that Starbucks triple shot venti caramel latte and one of our "third wave" overdosed 22g triple basket espressos.

Does quality coffee always have to be delivered in sledgehammer quantities? At times all the customer wants or needs is a tiny cup. So shouldn't a good barista be able to pour an excellent single? And for Clover coffee, a cup doesn't need to be a jitter-inducing 16 oz. Are the customers so brainwashed by McDonald's and Burger King that they can't appreciate sensibly-sized coffees? If they are brainwashed, perhaps we need to make more effort to educate them about this, just as we educate them about single origins and sustainable farming.

Many baristas and cafe staff are drinking big coffees so often that they've developed a tolerance. But 22g overdosed triples deliver huge amounts of caffeine, and not everyone can handle this volume of stimulant. When not in denial, even barista champions realize they're having trouble managing caffeine intake.

Seems like a significant step in the evolution of our fledgling espresso culture will take place when everything isn't Oversized, Overcaffeinated, and Over The Top. That's the province of Starbucks and the other fast food, low-quality companies. Since coffee is both a drug and a culinary experience, shouldn't we take a different path? In the long run, restraint and elegance will serve us better than brute force.

In quality cuisine, Less is More.

Take the dogma out for a walk

Somebody please slap me in the face.

The "third wave" espresso world seems so strange: "temperature stability" has become religious dogma.

And common sense no longer accounts for much.

If you're wondering what the heck I'm talking about, I'll try and explain.

A decade or more ago David Schomer popularized a theory that described how an espresso machine should work. If you made a graph of the brew water temperature that the machine delivered, it was supposed to be "ruler flat" for the duration of a shot.

For David's blend, that meant the water temperature should rise as rapidly as possible to 203.5F, and remain there until the shot was finished. Other blends might have different optimum temperatures, or even several optimum temperatures, each expressing different qualities of flavor and texture. But it was a basic tenet in David's theory that the flat temp profile was necessary for the finest espresso.

Was this theory ever fairly tested? How did it become generally accepted? And how is it that the only machines acceptable for Barista Championships must perform this way?

In my opinion, the flat temperature theory, like the flat earth theory from centuries ago, doesn't bear close inspection. Here's why:

Coffee in the portafilter starts out slightly warmer than room temperature (it picks up a little heat in the grinding process). Even if you force water through it that is absolutely stable in temperature, the coffee in the middle and bottom of the puck gradually rises in temperature as the shot proceeds. It gets close to the temperature of the brew water, but never reaches it.

In other words, ESPRESSO IS NEVER EXTRACTED AT A STABLE TEMPERATURE, no matter what the brew water temperature does.

That's why insisting on ruler flat brew water temperature seems like a very peculiar requirement to make the finest espresso.

According to Michael Teahan, the Italians recognize this fact. Many Italian machine tuners prefer to start their brew water temperature very hot, gradually reducing it over the course of the extraction. This has the effect of getting the extraction environment in the basket up to temperature faster. But it still doesn't change the fact that, given the existing technology, IT IS IMPOSSIBLE TO EXTRACT ESPRESSO AT A STABLE TEMPERATURE.

But of course we all know that the Italians are backward buffoons, while we are cutting edge third wave baristas. Right? [please note, I'm being sarcastic here]

To be fair to David and his disciples, his theory has never been fairly tested because no one has an espresso machine that can accurately reproduce different brew temperature profiles. If an espresso machine could produce flat temperature profiles, rising temperature profiles, and falling temperature profiles at will, we'd be able to run some valuable experiments. Until then, we're stuck with comparing the espresso that comes from Synesso/GB5 machines (with their fairly flat profiles) to the espresso from heat exchanger machines (with their mostly falling profiles). But there are so many other variables (group and dispersion screen design, preinfusion scenarios, pressure variation, etc) that definitive conclusions are very difficult to come by.

In the absence of a technical breakthrough, many espresso machine designers have settled for a much less demanding requirement: they try and design their machines to reproduce the same temp profile with every shot. So whether you pull your shots one right after the other or a half hour apart, engineers nowadays take pains to make the machine deliver the same temperature profile each time. But this is a far cry from being able to tweak the temperature profile itself.

Hopefully more advanced machines will be introduced that will soon allow accurate temperature profile testing. Then will we replace conjecture and orthodoxy with actual experience. Until then, perhaps we should let the dogma out for a walk.