Memphis is all about the grit and the grind — which is great if you're talking basketball, but not so much if the topic is coffee (the "grit" part, at least). Next to buying a fresh-roasted, whole-bean specialty coffee, the three variables that most affect the quality of your cup are the grind, your water, and your choice of brew method (which is more or less a proper marriage of the first two variables). While these variables are unquestionably interlinked, the purpose of the next series of blog posts is to help explain how a fresh-roasted specialty coffee that looks and smells fantastic can still result in an awful cup of coffee. Trust me, this is one of those "don't throw the baby out with the bong-water" situations! Before knowing better, I wrongfully accused more than a handful of coffee roasters of having crap coffee, only for it to magically be awesome the next time around. Yeah... it was straight up operator error (my own).
Through this series of posts, we will navigate you through some of the most egregious missteps with respect to preparing coffee and how your choice of brew method affects grind-size, etc., by giving step-by-step directions on how to prepare some of the more popular brew methods (French press, pour-over, etc.). Perhaps most importantly, we will suggest what corrections you might make if your cup initially tastes flawed (too acidic, too bitter, etc.), which is much easier to understand if you first understand how grinding coffee and your water (source, temperature, how long coffee is left in the water, etc.) independently affect your cup and the interplay between the two.
This first post explains why the grind is so important and hopes to encourage you to invest in a good grinder (if you don't already own one). Then you will begin to be able to appreciate coffee how it should be — i.e., a specialty craft beverage to be savored, not the sugar-and-cream-filled commodity jitter juice of commercial coffee dens that students clamor to mainline while cramming for finals.
Frame of Grind
For its part, grinding is a necessary (however barbaric) endeavor, but one that should be delayed until the last possible second — like death. It's an apt comparison once you consider that, when it comes to making something you can drink from a coffee bean, grinding is as unavoidable as death and taxes and also exposes your beans to a host of potential flavor-polluting pitfalls. Your decisions at grind-time also affect how your coffee tastes, finishes, feels in your mouth, etc.
One would never buy a Screaming Eagle Cabernet 1992, open it to breathe, only to forget about it for a few days then drink it from a red Solo cup. Some well-intentioned oenophile would likely pay good money to see such a heretic drawn and quartered. And while specialty coffee — even the most expensive in the world, Hacienda La Esmeralda (Panama) — is on orders of magnitude cheaper than the '92 Screaming Eagle Cab (upwards of $7K per bottle vs. ~$325 per pound), there's still much that coffee connoisseurs may learn from the attention that wine aficionados pay to each bottle. But while wine producers and vintners handle most of crucial details in the wine industry, the same is not true for coffee. On the one hand, with wine, a consumer's choices are limited and relatively straightforward: proper storage, serving temperature, glassware, and aeration. Coffee, on the other hand, has many more variables under the consumer's direct control, however unwittingly. And each of these decisions (or omissions) affects the final product.
One of the reasons is chemistry. Green coffee beans have over 250 compounds that influence flavor; roasting the coffee raises the potential compounds another 655 to 800 to roughly 1000 compounds at grind-time. Upon grinding, though, coffee immediately begins to give up many of these flavors through oxidation (oxygen depletes about 60% of a coffee's aroma within 15 minutes of grinding), contamination (the smaller particle size of ground coffee allows smells from the environment to overpower coffee's aroma), moisture in the air (coffee's oils are water-soluble, which is key to delivering flavor, but also makes the oils susceptible to atmospheric moisture attaching to the grinds and leeching away flavor prematurely), and carbon dioxide depletion (carbon dioxide from the roasting process plays a crucial role in helping infuse the oils from the beans into the beverage, yet 80% of carbon dioxide is lost within 60 seconds of grinding your coffee beans). In short, grind too soon (or, even worse buying pre-ground coffee) and you sacrifice many of the flavors and aromas that have the potential to make coffee fantastic. Lesson: Wait till the last possible second before brewing to grind your coffee.
An Axe, er, Burr to Grind
When you grind coffee is arguably the most important factor the consumer can control. But a close second is how you grind your coffee. If you're serious about your coffee and wish to have a consistently good cup, a burr grinder is absolutely essential (We sell two in our affiliate store here: one for home use and one for travel). That's because having a consistent, precise grind leads to a more consistent cup, free of defects.
Like fine wine, specialty coffee needs to be treated with some TLC to produce a cup with the best flavor profile. Roasted coffee beans are fragile and fracture very easily. You can actually crush a roasted bean between your fingers. This brittleness lends itself to an unfortunate side effect: fines — a powder-like coffee dust. The problem with fines is that they are prone to over-extraction, where hot water leaches out too many chemical compounds and ends up resulting in a bitter, astringent (and altogether unpleasant) finish. Because of roasted coffee's brittleness, fines are always present, so the goal is to limit how many fines end up in your ground coffee.
For this reason, blade grinders are a non starter: They simply pulverize coffee into oblivion, with many of the grounds ending up as fines. On the other hand, burr grinders are much "gentler" on the coffee bean than a blade grinder — which Serious Eats likened to chopping tomatoes with a mallet rather than a chef's knife. Because burr grinders result in far fewer fines in your filter or puck, the end result is a cup of coffee that is far more likely to be free of defects like bitterness.
The other advantage that burr grinders have over blade grinders is that they produce a far more consistent grind size. This means that you end up with a consistent extraction because by and large the same amount of water is coming into contact with the same number and same size of coffee particles. The explanation of grind profiles in the Serious Eats article does a good job of explaining how this works and why it is important. For the consumer, it comes down to this: Burr grinders produce a consistent grind size, which leads to a consistent cup of coffee; blade grinders do not.In sum:
- Buy a fresh, whole-bean specialty coffee;
- Wait till the last second before brewing to grind it; and
- Use a burr grinder.
Got it? Good. Next week, we'll discuss water and the interplay between water and ground coffee to be followed up with several posts discussing various brew methods.