The discovery that the seeds of the coffee fruit tasted good when roasted was undoubtedly the key moment in coffee history. It marked the beginning of the transformation of coffee from an obscure medicinal herb known only in the horn of Africa and Southern Arabia to the most popular beverage in the world, a beverage so widely drunk that today its trade generates more money than any other commodity except oil.
When European travelers first encountered the beverage in the coffeehouses of Syria, Egypt and Turkey in the 16th century, the beans from which it was brewed came from terraced fields in the mountains at the southern tip of the Arabian peninsula, in what is now Yemen. Consequently, when the European botanist Linnaeus began naming and categorizing the flora of the astounding new worlds his colleagues were encountering, he assigned the coffee tree the species name Coffea arabica.
No one knows how Coffea arabica first came to be cultivated, when, or even where. Some historians assume that it was first cultivated in Yemen, but a strong case has been made that it was first deliberately grown in its botanical home Ethiopia, and was carried from there to South Arabia as an already domesticated species, perhaps as early as AD 575.
Considerable speculation has been focused on what finally led someone in Syria, Persia, or possibly Turkey to subject the seeds of the coffee fruit alone to a sufficiently high temperature (around 465F/240C) to induce pyrolysis, thus developing the delicate flavor oils that speak to the palate so eloquently and are undoubtedly responsible for the eventual cultural victory of coffee.
Ottoman Turks were the main instigators of the spread of coffee drinking and technology, since their expanding empire facilitated cultural and commercial exchange.
By 1550 coffee seeds or beans were definitely being roasted in the true sense of the word in Syria and Turkey, and the spectacular rise of roasted coffee to worldwide prominence in culture and commerce had begun.
Early coffee roasting in Arabia was doubtless simple in the extreme. We have no detailed accounts of these earliest of roasting sessions, but they probably resemble the practices still found in Arabia today, and recorded by Europeans like William Palgrave in 1863 in his Narrative of a Year's Journey Through Central and Eastern Arabia:
... Among the inhabitants of the Arabian peninsula roasting, pulverizing, brewing and drinking the coffee all were (and often still are) performed in one long, leisurely sitting. Both roasting and brewing are carried out over the same small fire. The roasting beans are stirred with an iron rod flattened at one end. After cooling they are dumped into a mortar, where they were pulverized to a coarse powder. The coffee is boiled, usually with some cardamom or saffron added, then strained into cups. It is drunk unsweetened.
From Brown to Black: A New Coffee Cuisine
Arabians roasted their coffee a rather light brown color. At an early point in coffee history, probably before 1600, a somewhat different approach to coffee roasting and cuisine developed in Turkey, Syria, and Egypt. The beans were brought to a very dark, almost black color, ground to a very fine powder using either a millstone or a grinder with metal burrs, and boiled and served with sugar. No spices were added to the cup, and the coffee was not strained, but delivered with some of the powdery grounds still floating in the coffee, suspended in the sweet liquid. It was served in small cups rather than the somewhat larger cups preferred by the Arabians.
This coffee cuisine is called "Turkish." Why Turkish? Why not Egyptian, for example, or Syrian? Because this cuisine penetrated Europe via contacts with the Ottoman Turks, first through Venice into Northern Italy, and later through the Balkans and Vienna into Central Europe. Early European coffee drinkers all roasted their coffee very dark and drank it in the "Turkish" fashion, boiled with sugar.
Coffee Goes Global
The 17th and early 18th centuries saw the habit of coffee drinking spread westward across Europe and eastward into India and what is now Indonesia. As a cultivated plant it burst out of Yemen; first a Muslim pilgrim carried it to India, then Europeans took it to Ceylon and Java. From Java they carried it to indoor botanical gardens in Amsterdam and Paris, then as a lucrative new crop to the Caribbean and South America, where in a few short decades millions of trees were providing revenue for plantation owners and merchants and mental fuel for a new generation of philosophers and thinkers gathering in the coffeehouses of London, Paris, and Vienna. Click Here for more information on Coffee By Country
Roasting in a Technological Rut
Despite these dramatic developments in coffee drinking and growing during the 17th and 18th centuries, roasting technology itself changed very little. The most common approach was a simple carry-over from Middle-Eastern practice. Beans were put in an iron pan over a fire and stirred until they were brown. Somewhat more sophisticated devices tumbled the beans inside metal cylinders or globes that were suspended over a fire and turned by hand. Some of these apparatus could roast several pounds of coffee at a time and were used in coffeehouses and small retail shops; others roasted a pound or less over the embers of home fireplaces.
Roast Style and Geography
Taste in darkness of roast doubtless differed from place to place according to cultural preference, much as it does today. In most of Europe during the 16th and 17th centuries coffee continued to be roasted in dark, Turkish style. A pamphlet from 17th century England, for example, advises coffee lovers to "...take what quantity [of coffee beans] you please and over a charcoal fire, in an old pudding pan or frying pan, keep them always stirring til they be quite black..."
At some point, however, tastes in Northern Europe Germany, Scandinavia and England modulated to a lighter roast than the rest of Europe, which retained a preference for somewhat darker roasts deriving from the Turkish tradition. This distinction carried over to the New World: North Americans largely adopted the lighter roasts of the dominant Northern European colonists and Latin Americans the darker roasts of their Southern European colonizers. Arabia and parts of the horn of Africa retained their original taste for a lighter roast coffee, drunk with spices but without sugar.
Enter the Industrial Revolution
As the 19th century began coffee was roasted in small, simple machines, either at home or in shops and coffeehouses. By the end of the century the new urban middle class was increasingly buying a coffee roasted in large, sophisticated machines and sold in packages by brand name.
Further technical innovations focused on two problems: 1) controlling the timing or duration of the roast with precision, and 2) achieving an even roast from bean to bean and around the circumference of each individual bean.
Starting in 1867 fans or air pumps were introduced to automate the cooling. The beans were dumped into large pans or trays. While machine-driven paddles stirred the beans fans pulled cool air through them, both reducing their surface temperature and carrying away the smoke produced by the freshly roasted beans.
The second technical problem was addressed when toward the end of the century hot air was drawn through the drum by a fan or air pump, often the same fan or pump used to pull air through the beans to cool them. The combination of moving air and vanes tossing the coffee meant the coffee was roasted more by contact with hot air than through contact with hot metal, improving both the consistency and the speed of the roast.
20th Century Innovations
Obviously the 20th century could not leave coffee roasting technology alone. In 1934 the Jabez Burns company developed a machine that applied no heat whatsoever to the drum itself, instead relying entirely on a powerful stream of hot air howling through the drum.
Roasting Without End: The Continuous Roaster
For large roasting companies time is money, and emptying beans from the roaster and reloading with more beans takes time. Such economic motives lay behind still another 20th century development, the continuous roaster, in which the roasting process never stops until the machine is turned off.
The most common continuous roasting design elongates the typical roasting drum and puts a sort of screw arrangement inside it. As the drum turns the screw-like vanes transport the coffee from one end of the drum to the other in a slow, one-way trip. Hot air is circulated through and across the drum at the front end and cool air at the far end. The movement of the beans through the drum is timed so that green coffee entering the drum is first roasted, then cooled by the time it tumbles out at the end of its journey. Variations of this principal continue to be employed in machines used today in many large commercial roasting establishments.
A Revolution in Measurement and Control
As we approach the 21st century there are signs that roasting technology may be undergoing still another revolution. Barring some breakthrough in the use of microwaves, it seemed unlikely that the basic technologies for applying heat to the beans and keeping them moving will change. What is changing is the way the roast is monitored and controlled.
Traditionalists: Nose and Eye
Traditional roasters rely on the eye, carefully observing the developing color of the roast by means of a little instrument called a trier, which they insert through a hole in the front of the roasting machine to collect a sample of the tumbling beans. The decision when to stop the roast is based on the color of the beans read in light of experience. Adjustments to the temperature inside the roast chamber also may be made on the basis of experience, experience both with roasting generally and with the idiosyncrasies of specific coffees.
Science Sneaks Up on Art
What was once a matter of art and the human senses, however, is increasingly becoming a matter of science and instrumentation, in which individual memory is replaced by an externalized, collective memory of numbers and graphs.
Some extremely sophisticated roasting apparatus is now being constructed with spectrophotometers built into the roasting chamber, so that the gradually deepening color of the roast appears translated as a series of numbers on a display, and the roast can be terminated precisely and automatically on the basis of a predetermined color reading.
But It Still Needs to Be Tasted
One human sense that hopefully will never become obsolete is taste. For even if the day arrives when roasting is performed entirely on the basis of system and number, the roaster (or roastmaster as he/she is increasingly called in these up-scale days) still will need to taste the coffee when it comes out of the roasting apparatus and make some informed adjustments to those numbers based on personal preference and roasting philosophy. Thus the variety of taste achieved by different approaches to roasting may continue to surprise our palates and enrich the culture and connoisseurship of coffee. And roasting, perhaps, will remain art as well as science.
Social History: Quality Makes a Comeback
To conclude, let's return to the social history of roasting and bring it to its rather surprising conclusion in the 20th century.
Although pre-roasted, pre-ground coffee sold under brand names claimed more and more of the market in industrialized Europe and America during the first half of the 20th century, older customs hung on. In southern Europe many people continued to roast their coffee at home well into the 1960s, and even in the United States numerous small, storefront roasting shops survived.
By the 1960s packaged coffee identified by brand name dominated the urbanized world. A few storefront roasters hung on here and there in larger cities, but the simple process of home roasting became a lost art, pursued in industrialized societies only by a handful of cranky individualists.
The few surviving shops that still roasted their own coffee and sold it in bulk provided a foundation for a revival of quality coffees that has taken on an extraordinary power in the United States, and in many other parts of the industrialized world.
This revival is usually called the specialty coffee movement. Thus the end of the 20th century is witnessing a return to people buying coffee in bulk and grinding it themselves before brewing. Perhaps the United States, which led the world down the superhighway of convenience, may be pointing it back along the slower road toward quality and authenticity.
Quirky and Individualistic
Starbucks is in many ways a happy marriage between the quality-conscious idealism of the specialty coffee movement and rigorous corporate power and discipline. Nevertheless it does not entirely represent the world of coffee as I would like to see it enter the 21st century: quirky and individualistic, with local roasters selling their own style of coffee in their own neighborhoods, a world full of choice and surprises.
For those who really love coffee, the moment may have come to leave cans and enormous coffee store chains behind and enjoy coffee as people did before the advent of brand names, chain stores and advertising: by roasting your own.