Coffee is part of the daily lives of millions of people and the way it is produced and prepared has changed significantly over the centuries. Portal popsci.com speakToday, how does a coffee bean go from the tree to the hot cup?
The fruit of the coffee plant is not the same color as the dark brown liquid in the coffee pot. In its original form, coffee is a lush leafy plant with bright red berries. There are more than 130 varieties of coffee plants on the planet, but only Arabica and Robusta varieties are grown to produce coffee.
Arabica originated in Ethiopia but is now grown around the world, especially in Brazil, while Robusta coffee is grown in Africa, Indonesia and India. The main difference between the two is that Arabica beans have a milder flavor and a slightly more fruity flavor, while Robusta produces a rich, full-bodied coffee that is great for making espresso.
However, the coffee bean itself only accounts for a portion of the flavor. In fact, “bean” refers to the seeds contained inside the coffee fruit.
When harvesting and processing coffee, the ripeness of the berries can greatly influence the taste of the drink: even after removing the seeds, the berries leave behind an aroma. Additionally, there are several ways to separate the fruit and beans — or process the coffee that will later be turned into beans. So, crushing the fruit pulp leads to a more sour taste, and partial fermentation leads to a more fruity taste.
After processing, coffee beans still have a long way to go to get a cup of coffee. Processed beans, also known as “green” beans, initially have a characteristic coffee aroma, but to fully develop, the beans must be roasted. At this stage, coffee beans undergo a number of changes, the most important of which is the Maillard reaction, in which sugars and amino acids give coffee its unique aroma.
Essentially, when looking at roasting from a flavor perspective, producers must find a balance between two different characteristics—acidity and bitterness. The longer coffee beans are roasted, the more acidic compounds are decomposed. That is, fans of more acidic coffee should take a closer look at lightly roasted beans. And the classic bitter taste is the result of a long roasting process, but it can also lead to the loss of the original aroma of the beans. Even small changes in roasting can seriously affect the final flavor of the brewed coffee.
The roasted beans are allowed to rest briefly before moving on to the next stage of production. The fact is that freshly roasted beans contain a lot of carbon dioxide – coffee from them will be very frothy. For example, dark roast coffee needs to rest for a month to six weeks, while light roast coffee needs to rest a little less.
Finally, coffee not only has many processing methods but also many brewing methods. In general, coarsely ground beans are better suited to French press or cold brew. And the fine grind is ideal for espresso makers, geyser coffee makers, and even Turks.
Optimal grindability is influenced by a number of factors, including the type of coffee and its age. For example, for espresso, light roast beans should be ground finer than dark roast beans, but the fresher the beans, the coarser the grind. This will help balance the amount of crema at the top of the espresso.
Water temperature is also important. Many experts recommend brewing coffee with water heated to near boiling. At high temperatures, the bitterness of coffee increases due to the rapid removal of molecules; If you overdo it, water that is too hot will cause the coffee to deoxidize and become even more bitter.
