Espresso: The Art of Flavor Extraction

The word espresso is derived from the Italian word for express since espresso is made for and served immediately to the customer.  Espresso is a method of extracting flavor from coffee beans using water which is not quite boiling and under a lot of pressure. The "under a lot of pressure" and "not quite boiling" bits are critical to making good espresso. A double espresso is a 1.5-2 ounce extract that is prepared from 14-17 grams of coffee through which purified water of 88-95°C has been forced at 9-10 atmospheres of pressure for a brew time of 22-28 seconds. The espresso should drip out of the porta-filter like warm honey, have a deep reddish-brown color, and a crema that makes up 10-30% of the beverage. 

Espresso brewing is an art form defined by four "M's": the Macinazione is the correct grinding of a coffee blend, Miscela is the coffee blend, Macchina is the espresso machine, and Mano is the skilled hand of the barista. When each factor of the four M's is precisely controlled, the espresso beverage that is produced is the ultimate coffee experience.

Machines appropriate for most homes that can do this all at once were only invented in this century. Most low-end home espresso machines settle for "some" pressure, and cheat on the "not quite boiling" part as well. The result is often a strong but bitter, acidic coffee, nothing like a true espresso. There are many different versions of home machines to help create espresso. Some utilize a hand-operated lever, some are stove-top devices, and there is also many varieties of the inexpensive electric pump style brewer. Pump machines limit your creative freedom when brewing espresso and you tend to get what you pay for.

Stovetop espresso makers ($12 and up) can make a decent espresso, and can be found in most specialty shops that sell coffees. The basic problems are inadequate pressure and boiling water. If you must, splurge for one made of stainless steel (not aluminum), tamp ground coffee at your own risk (you are betting the safety release valve will function properly), and coax the coffee out slowly, stopping early. With practice, the right River Road Coffee, and the proper equipment, you too can master the art of brewing espresso at home.