Italian espresso-style coffee is a cultural phenomenon that has spread across the world and has spurred a specialty coffee revolution which accounts for a significant portion of the more than $80 billion that is spent annually on coffee of all forms. Nearly 120 million 60 kg (about 132 1b) bags of coffee are produced annually making coffee the second most important legal global commodity behind oil. Coffeehouses are public places of intellectual, artistic, and social significance that have origins in the early sixteenth century on the Arabian Peninsula and are frequently cited as the birthplace of such major revolutions as the American and the French.

Espresso is particularly suited to the social quality of the coffeehouse because of the expense of the technology as well as the skill required to properly prepare it and the on-demand character of its preparation. The resulting deep and flavorful brew and the array of beverages made with it—from traditional Italian macchiattos and cappuccinos to American-style flavored lattes, mochas, and blended coffee beverages—have rapidly spread in popularity across the world (Davids 2001). Even coffee-producing countries are catching on to the phenomenon and keeping for themselves some of the better quality coffee, beans traditionally reserved solely for export. Nearly a quarter of all coffee produced is now consumed in the countries where it is grown (Pendergrast 1999). Today, espresso-style coffee retains a history as rich, deep, and bittersweet as its flavor.

Origin of Coffee

Espresso-style coffee is one of numerous methods for brewing the roasted and ground seed of the coffee tree, but espresso is unique for its dependence on modern technological advances. The sophisticated machinery of today can be seen as a culmination of one strand of coffee’s diverse history, rooted in the drive for intensely concentrated, full-bodied, but filtered coffee (a major distinction of espresso from Turkish-style coffee). It is only one cultural definition of many traditions that have emerged in the broad history of coffee that reaches back some fifteen centuries when, as legend has it, an Ethiopian goatherd named Kaldi discovered his goats overly excited as a result of eating a mysterious fruit off an unfamiliar tree. He finally worked up the courage to try the coffee “cherry” and quickly felt the unusual sense of excitement, inspiration, and clarity that came from it...and that continues to be sought after today. The early use of the Ethiopian coffee tree (binomial name Coffea arabica) was, however, little more than a tea-like beverage steeped from a macerated concoction of the cherry, seed, and leaves--a far cry from the smoky and bittersweet deeply colored brew of today's espresso “shot.” And yet geographical influences are integral to the understanding of the science of espresso because of the relationship between the coffee seed and its surrounding environment. From its origin in Ethiopia and its earliest cultivation on the Arabian Peninsula, coffee has been smuggled, traded, and extensively cultivated across the world (Pendergrast 1999).

Global Cultivation and Nineteenth Century Europe

By the middle of the nineteenth century, cultivation of coffee had reached to its farthest extent where coffee can grow, covering the vast majority of countries between the Tropics of Cancer and Capricorn. At the same time, coffee consumption continued to skyrocket in non-coffee-producing countries. Europeans began importing commercially through Venice in the early decades of the eighteenth century, but coffee already had roots in Europe dating to the Ottoman Empire’s failed siege on Vienna in 1683. So the story goes, when the Ottoman Turks pulled out, they left their large provision of coffee behind and enterprising businessmen in Vienna used the supply to open up the first Viennese cafés. It is also in Vienna where it is believed filtered coffee and cow’s milk were first combined in the café setting for widespread distribution. Turkish-style coffee almost certainly dominated the early menu, but experimentation lead to the predecessors of the milky espresso beverages popular today. From Vienna, the taste for filtered coffee and milk worked its way south into Italy where the inhabitants of Austrian-controlled Milan quickly took to the beverage and began their own experimentation with it. The cultural phenomenon that emerged seemed almost predestined, “as though the ideal of espresso was somehow present from the moment northern Italians developed a taste” for the Viennese coffee, for Italians immediately set out in pursuit of perfecting that “strong and heavy-bodied, yet filtered” brew (Davids 2001).

“Pressed Out” Coffee On-Demand: The Technology of Espresso

The earliest brewers that attempted to use pressure to extract coffee appeared on the scene in the nineteenth century and such technology is the origin for the name espresso: to be “pressed out” and made “expressly” for the consumer on demand. The most direct predecessor to the modern commercial espresso machine appeared around the turn of the century “to meet the demand for an ‘instant’ brew” (Pendergrast 1999). Luigi Bezzera patented a machine that met that demand and began producing the first “dark, rich, complex, concentrated, satiny” espresso shots “with a rich hazel-colored crema on top and an overwhelming aroma” (Pendergrast 1999). The language of espresso was born and, in particular, the innovations that followed were built in the pursuit of perfect “crema,” the sweet and foamy lighter-colored layer with a “tiger-skin” effect that is characteristic of quality espresso (Illy and Viani).

Prized espresso brewing occurs at the molecular level through a series of intricate chemical reactions involving the volatile organic compounds present within the coffee bean. For this reason, technology is vital to espresso, though various gadgets have long been implemented in the brewing of coffee of all forms. Steam pressure was the first innovation in pushing water through the compact ground coffee, but any attempts to apply additional pressure from steam damaged the espresso by cooking or burning it, so steam-powered machines proved insufficient to the task.

Soon after World War II, inventor Achille Gaggia in Italy developed spring-powered machines that used a manually operated lever to push hot water through the coffee by expansion of a spring above a piston positioned over the “portafilter” at the brewing group head. The filter and brew head mechanisms developed in the early twentieth century remain largely intact on modern semi-automatic espresso machines. Gaggia’s machine used pressure six to nine times greater than that of the steam-powered predecessors and produced a fuller-bodied shot with an exquisite layer of sweet crema. Hydraulics and electronic pumps eventually replaced the screw-and-piston, and further refinements including electronic instrumentation allowed for higher quality and greater consistency (Davids 2001).

In addition to some fundamental mechanical and design elements, what has also remained relatively intact is the interaction between machine and bartender, or the now omnipresent barista, in Italian. Even on semi-automatic espresso machines, the barista grinds fresh coffee into the portafilter and then applies manual pressure called a “tamp” into the bed of the portafilter to make a “cake.” The barista’s efforts combine with the work of the machine which forces the water through the coffee. This sequence is a large part of the romance of the artesian coffeehouse. Even machines with automatic brewing mechanisms require manual steaming of milk for the vast array of beverages now made out of espresso coffee. However, espresso purists argue that the fully automatic espresso machines available today that use advanced technology in the attempt to perform the same tasks come nowhere close to succeeding.

Blending and Roasting: The Art of Espresso

The spread of coffee across the world is significant for perfecting the espresso shot because the scant ounce or so of liquid is treated by master roasters as a fine art. Once brewed, the perfect, artistically crafted blend can embody for professional coffee tasters global coffee excellence. Distinct regional attributes affect the taste of the carefully grown and processed coffee cherry in the same manner as wine. Consequently, coffee experts refer to the terroir of a region, a French word signifying the summation of those attributes which directly affect the final product. The unroasted “green” coffee seed is initially affected most directly by climate, soil, and terrain, among other factors, though methods of growing, harvesting, and processing can further alter the result in the cup.

A combination of heavy-bodied coffees from an Indonesian island such as Sumatra with bright, sparkling coffees from Latin America along with exotically aromatic coffees from East African countries or those from the Arabian Peninsula with floral and fruity flavor notes is a likely combination for many proprietary blends. Since worldwide coffee cultivation has existed as long as espresso technology, it is safe to assume that experts have long been blending and roasting multiple-origin coffees according to their taste. Italian roasters are not opposed to using a small amount of high quality Coffea canephora, or robusta, in their espresso blends for its heavy body, but the species is typically much less desired and fetches a much lower price worldwide.

Finally, espresso beverages in Italian-American cuisine, and the Seattle coffee cuisine they inspired, have direct Italian ancestry and specific parameters for the ideal shot of espresso, with slight variations depending on the business, the barista, and the coffee itself (Davids 2001). Those parameters make up the basic structure of a thoroughly analyzed organic product—a product that at its best contains hundreds of individual flavor compounds, and even more than wine. For that ounce of espresso comprising a single shot, seven to nine grams of finely ground coffee is used. Frequently, machines are designed to pull two shots, which use up to eighteen grams of ground coffee. Filtered water heated to 195-205 degrees Fahrenheit is pressed through the carefully tamped powder at very high pressure in the range of twenty to thirty seconds for two shots of brewed espresso.

Because of the combined nature of the technology used, espresso and only espresso can be defined as “a small cup of concentrated brew prepared on request by extraction of ground roasted coffee beans, with hot water under pressure for a defined short time” (Illy and Viani 2005). Espresso machines push the water with high pressure through the “compact bed of ground coffee” and the rapidly brewed or “percolated” coffee is forced through a metal filter resulting in a complex and volatile liquid that is meant to be consumed immediately because it quickly breaks down in quality. Pressure and brew time are quintessential terms describing espresso. For espresso, the last century of technology has been developed in pursuit of achieving a perfect harmony of both in order to extract from the ideally blended, roasted, and ground coffee what the connoisseur of espresso defines as the perfect shot (Illy and Viani 2005).

With coffeehouses based on the Italian espresso model flourishing in America and across the world, the modern history of coffee will continue to be written. And though in the American experience the original Italian espresso is often obscured among a myriad of flavor and milk combinations, the essential component is available and, at quality coffeehouses everywhere, can be easily ordered in all its unadulterated purity.

Davids, Kenneth. 2001. Espresso: Ultimate Coffee. New York: St. Martin’s Griffin.

Illy, Andrea and Rinantonio Viani, eds. 2005. Espresso Coffee: The Science of Quality. Amsterdam: Elsevier Academic Press.