It has long perplexed many a grad student why in-depth learning about a topic should work so in reverse, leaving you knowing (or at least feeling like you know) exponentially less than you knew when you began a course of study. As Confucius said, "Real knowledge is to know the extent of one's ignorance." Not especially comforting words. But assuming they are true, then I have to conclude that I am sitting on a wealth of new coffee knowledge, and that it is due in large part to something affectionately known as the "2010 Grinder Smackdown."
Nate Jones compares lattes from the Swift grinder, rating consistency.
Hosted by Roaster Philip Meech at Caffe Lusso in Redmond, the "Grinder Smackdown" was the opening event in a projected series of coffee tastings designed to compare different elements of different brewing methods, and, by virtue of blind testing, determine the worth of a few industry claims. Great idea, but not an event for the faint of heart-- figuratively, or literally, considering how much caffeine ends up being consumed.
For most of us in the coffee drinking world, there are two basic kinds of espresso grinders--and they're pretty simple, right? Either the coffee shop uses the push-a-button kind, or it uses the pull-a-lever kind. Before last week, I was unaware that a Google search for "commercial coffee grinder" would yield so many hundreds of options, each claiming to be the absolute best and to solve some problem that another grinder creates.
Unlike questions of coffee origin and coffee cuppings --things long since "familiar" on the Seattle coffee scene-- let me tell you that there is still a certain joyous bliss to living in coffee grinding and dosing ignorance, and it may actually be more fun to stay there. Leave it to a guy like Philip to completely shatter said blissful existence by organizing a side-by-side blind tasting of espresso from two different grinders. And not even grinders as conveniently different as "push button" and "pull lever" grinders, either. No, the contenders in question last week were the La Marzocco Swift and the Mahlkönig K30 Vario... both involve pushing a button. Both grinders are grind-on-demand models with automatic dosing. Both are burr, not blade grinders. The primary differences between them are the method of distribution and a manual vs. automatic tamp.
http://www.mahlkoenig.com The oh-so-shiny Vario
After about 3 1/2 hours of coffee tasting and talking with the likes of The Coffee Catcher's Nate Jones, and 2008 Italian Cup Tasting Champ Sauro Dall'Aglio, I can tell you that I now know a lot more about grinders (and my exact caffeine tolerance) than I did. And most of it, I don't understand. But for the purpose of this write up, here is what's relevant to your average, daily coffee drinking, so that you can at least begin to know the extent of everyone else's ignorance.
First off, if you didn't know it, espresso grinders play a key role in your overall espresso experience. Several elements of a perfect espresso shot fall to the grinder's realm of responsibility, among them grind, dose, and packing, all of which impact extraction.
GRIND: Whether a grinder uses a burr or blade to grind the coffee beans into coffee grounds, the ideal grind will have a high rate of consistency and a low rate of clumping. Water always travels first along the path of least resistance, and the idea in creating an even grind is to get the water to flow evenly through all of the coffee, and extract all of the flavor, rather than flowing primarily around clumps of coffee or through the thinnest layer of coffee, resulting in under-extraction or over-extraction of flavor, respectively.
DOSE: We all know that putting three or four bags of tea into one 12-ounce cup of hot water is a poor idea. Similarly, with coffee, there is an ideal ratio of coffee:water. Grinders with automatic dosing like the Swift have far less convenient control over this ratio than do manual grinders, or even highly modifiable "auto" dosing grinders like the Vario. This can be argued as either a positive or negative attribute, but across the board is recognized to increase consistency beverage to beverage. (When it increases it to be consistently better, awesome. When it increases it to be consistently worse, adjusting the dose is time-consuming and tricky, and many baristas are not trained to do it.)
Adjusting "dose" on the Swift is a little complicated.
PACKING: Various arguments are made, but essentially, the same principles apply to automatic packing as do to automatic dosing: an automatic tamp should be the same every single time. The primary things to consider in packing espresso are even, level distribution and tamping pressure. As far as I'm aware, the current "standard ideal" pressure for packing coffee grounds into a portafilter is debatable between 30 and 60 pounds of pressure. The more pressure, the more tightly packed the grounds will be, the more difficult it is for water to flow through them, the longer the coffee is (effectively) "cooked" by the heat.
EXTRACTION: Finally, extraction is the point at which the three previous elements become relevant to your morning espresso. Any minute change in the grind, the dose, or the tamping can impact the time, volume, and flavor of the espresso shot. What this means to you, as a coffee drinker, is that handing a beverage back to your barista and complaining that it is "burnt" should be done with compassion and patience, understanding that the number of variables a barista has to adjust in order to figure out which KIND of "burnt" flavor you are getting and why is actually a pretty significant number, and the solution is very rarely a no-brainer.
For example: the two grinders involved in this test, the Swift and the Vario, turned out to produce two vastly different espressos. Using the same beans, and pulling shots the same length, the Vario's espresso was more well balanced, with a fuller body and softer flavor. The Swift produced an espresso that was, as Sauro Dall'Aglio put it, "ashy" - comparatively more bitter, with less dimension and balance. And that's where it really got interesting: The Vario's espresso shot (without dispute among those present) was preferred for americanos, and espressos. The shots from the Swift were (again without dispute) preferred for milk-based drinks like lattes, because the more strident flavor profile stood up better to the milk.
Espresso, like any other art form, has objective standards, but is actually highly subjective in terms of enjoyment. You can bet that coffee shops using the La Marzocco Swift grinder have made that selection because they know that the bulk of their clientele will order milk-based and/or flavored beverages. If you are interested in finding a really good shot of straight espresso, you may want to consider another destination. Ultimately, what it comes down to is knowing why you like what you like so that you can find it.
...and none of us will ever sleep again.
That, and knowing just enough more than the average person to feel a little bit smug when you take a sip of your morning brew and say to yourself, "Hmm. I think perhaps the grind was off today..."