A piece of equipment that plays a crucial role in transforming green beans into the delicious coffee that we adore - the coffee roaster.
In today's session, Ro will delve into the evolution of coffee roasting machines, starting from the initial manual roasting methods employed by early coffee roasters to the latest automatic coffee roasting machines. You will discover the incredible progress made in the manufacturing of coffee roasting machines and how their invention has influenced the coffee industry and our everyday existence.
Roasting coffee in pans
Coffee has a long and fascinating history, with its origins dating back centuries to Africa and the Middle East. Over time, the Ottoman Empire and European colonisation spread the drink around the world. Early approaches to roasting coffee beans involved using thin, perforated pans over an open flame.
Roasting coffee in a pan. Source: Internet
This method required the user to stir the beans continuously, so as to ensure even roasting. This manual process allowed only a small amount of beans to be roasted at a time, necessitating close attention for the entire process.
Roasting coffee in pans was a common method in the early days of coffee roasting. Green coffee beans were placed in a frying pan or skillet and roasted over an open flame, usually on a stove or over a fire.
This method required constant stirring to ensure even roasting and prevent scorching. Roasting in pans was a labor-intensive process and the quality of the roast could vary depending on the skill of the roaster. However, it remained a popular method for home roasting until the development of specialized coffee roasting equipment in the 19th century.
Roasting coffee in a pan.Source: Internet
The cylindrical coffee roaster
According to reports, cylindrical coffee roasting machines first appeared in Grand Cairo during the 17th century. These machines had a chamber that enclosed the beans and allowed heat to circulate inside. Additionally, they featured hand cranks that ensured the beans were evenly stirred while the device was held over an open flame.
The enclosed chamber also meant that the fumes produced during the roasting process were significantly reduced, making coffee roasting more comfortable. Although the cylindrical roasting machines were modified and improved over time, the fundamental design remained unchanged. As colonialism fueled the growth of the coffee industry, the cylindrical roasting machine design spread to Europe and the Americas.
Cylindrical coffee roasting machines. Source: Perfect daily grind
The industrial coffee roaster
Industrialization had a significant impact on coffee roasting. During the 19th century, numerous patents for commercial machines were granted in both the US and Europe, even though many people continued to roast their small batches at home.
Early industrial roasters were usually massive cylinders placed over a heat source, typically wood or coal before natural gas became widely available. The smoky flavor of the coffee resulting from this heat source led to the preference for natural gas as a roaster's preferred heat source.
The first large-scale coffee roaster was patented by Richard Evans in the UK in 1824. Evans' design allowed the whole cylinder to be up-ended to empty it and featured an "examiner" that allowed samples to be taken throughout the roast.
In 1846, James Carter patented a "pull-out" iron drum in Boston, but this method of pulling the entire cylinder from the furnace and opening doors on the drum walls to dump coffee on the floor or into trays to cool was inefficient and dangerous.
Jabez Burns was granted a patent for a commercial machine in the US in 1864, which was an enclosed cylinder encased in brickwork. The design featured an opening mechanism to empty the beans without removing the cylinder from the flame and a double screw inside the cylinder that evenly distributed the beans.
These innovations made the roast more consistent and the process less hazardous. Burns' company later added a cooling tray to the front of the machine with a fan mounted below to draw air through the beans, paving the way for the modern coffee roasting machine.
An antique roasting machine at Vits in Munich, Germany. Source: Perfect daily grind.
The impact of electricity
With the increasing availability of electricity in the early 1900s, the coffee roasting industry underwent a transformation. The introduction of electric motors resulted in a significant reduction in labor required for roasting.
Additionally, the use of electric heat provided greater predictability compared to open flames, resulting in more consistent and safer roasting practices. Roasters were able to exercise greater control over the degree of heat exposure and replicate conditions with improved accuracy for the first time.
Cylindrical coffee roasting machines. Source: Perfect daily grind
Fluied-bed roasters
A fluid bed roaster is a type of coffee roasting machine that uses hot air to roast coffee beans. The coffee beans are suspended in the hot air stream, which helps them move and distribute heat evenly, resulting in a more uniform coffee bean surface.
Compared to traditional drum roasters, the fluid bed roaster can roast coffee beans more quickly and evenly. It is also easier to adjust the temperature and roast time to achieve the desired coffee flavor.
Source: Perusona Coffee Company
New technology
The modern coffee roasting process is informed by a better understanding of the chemical composition of coffee and the changes that occur during the roasting process. Coffee experts are better equipped to measure variables and analyze why a roast is successful or not. With technologies such as digital temperature-reading software and record-keeping, they can operate more efficiently and consistently than ever before.
Source: Internet
But these innovations rely on core inventions from over a century ago. Modern additions may help us control the roasting process better, but fundamentally they are refinements of 19th century drum roasting.
Overall, the coffee roaster is an important tool for anyone looking to create delicious, high-quality, consistent, and visually appealing coffee. It can significantly impact the taste, aroma, and overall quality of the coffee, making it an essential device in the coffee industry.
Reference:
https://perfectdailygrind.com/2019/09/discover-the-history-of-the-coffee-roaster/