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Celebration of International Coffee Day with Photonics Enthusiast, Sinan Genc

Coffee Day

Coffee is not just a drink, it is something that brings people together beyond geographical and cultural boundaries. It has a rich history dating back to the 13th century when a shepherd in Yemen observed that his goats became more energetic after consuming coffee fruit. Over time, coffee underwent transformations, evolving from fruit to roasted, ground, and brewed beans. So far it has gone through three waves up to now. Initially, companies did not provide any information about the origin of the beans or the processes required to prepare them for brewing. People used to believe that coffee came from a factory rather than a farm. In the second wave, companies, which we all know today and enjoy for their white chocolate mochas, began offering higher quality beans and disclosing the countries of origin. However, a gap still existed between the producer and the consumer. Finally, in the third wave, we can trace a cup of coffee back to its country and farm of origin. The names of the growers and the entire process are transparent. This transparency encourages producers to pay more attention and produce higher quality beans. So, is it enough to buy an expensive box of coffee?

My coffee plant

No, it’s not enough. The first and most crucial parameter is the type of beans: Arabica, Robusta, Excelsa, and Liberica. Arabica is the most common variety, grown at altitudes between 500m and 2500m. Latin America, especially Brazil, is currently the largest producer of Arabica beans, which constitute the majority of beans consumed today. Robusta beans, originating from Africa, Vietnam, and Indonesia, are known for their acidity and stronger flavor, making them ideal for espresso. The other types are less common and less commercialized, making them expensive and hard to find, and hence hard to experience and comment on.

So, what is the process of making coffee?  First, the coffee fruits are gathered. Then what? There are different processes to prepare beans for roasting. After mechanically extracting the green beans from the fruit, they can be washed to remove the pulp, a process called “washed.” If the beans are dried with the pulp intact, without washing, it’s called honey-processed. Another common method is the natural process, where the beans are left inside the fruit to dry as is. Regardless of the method, once the beans are dry, they are ready for roasting. Acidity, bitterness, sweetness, and saltiness are the four main characteristics of a cup of coffee. These flavors vary depending on where and when the beans are grown, how they are processed, roasted, and brewed. Roasted Arabica coffee is one of the most chemically complex beverages in existence.

My collection
My Coffee Collections

Water constitutes more than 90% of a cup of coffee. Even if you have high-quality beans, without appropriate water, it’s a dream to achieve good coffee. The water’s mineral levels, hardness, pH, and more are critical. Additionally, avoid boiling water; the temperature should be around 92-94°C to extract the best flavors. Mineral powders are available in the market to adjust distilled water to different profiles for a delightful cup of joy. Considering all these parameters, there are various methods to brew a cup of coffee: pour-over, immersion, cezve/briki, espresso, and more. For espresso, an Italian classic, 7-8g of finely ground coffee with 30mL of water is sufficient. In about 30 seconds, you achieve the desired yield, and the crema on top signifies quality. You can also discern hints about the taste from its appearance. As for other methods, varying the amount of water with the same amount of coffee results in a lungo (more water) or ristretto (less water). Adding steamed milk to espresso gives you options like cortado, cappuccino, macchiato, cafe latte, flat white, mocha (with chocolate), Vienna (with whipped cream), and more. Espresso serves as the base, allowing you to create your desired coffee experience.

Another method, pour-over, involves pouring hot water over coffee in known amounts and with precise heating. Tools like V60, origami, crystal eye, kono, and mugen allow you to control water flow and interaction time with coffee. However, be cautious with office coffee machines in this category, as the water is often too hot for a good cup of coffee. As an example, consider the V60 brewing process: Prepare 16g of appropriately ground coffee with a grinder, ensuring size distribution is critical. Place a filter paper in the tool and rinse it with hot water to remove any paper taste. Add coffee, slowly moisten it with 50mL of water, wait for blooming to release gas from the coffee grounds, and then pour 70mL of water with circular motions, being careful not to disturb the coffee bed. Repeat this process with another 70mL and finally complete it with 250mL. Now, imagine altering timing, water amounts, water temperature, coffee grind size, water contact time, and your circular motions to customize your brew.

My Realm of happiness and source of energy

Immersion methods involve combining all the coffee and hot water together, as seen with French press, AeroPress, or Clever Dripper. The challenge lies in controlling the parameters if you lack the necessary equipment. Lastly, the traditional cezve method involves placing 8-9 grams of coffee in the cezve and adding 70mL of water at 70°C. Stir slowly 2-3 times to combine, then put it on the stove for brewing. After about 1 minute, gently shake the cezve, and around 1.55 minutes, pour the coffee into a cup with a wider bottom part to retain the grounds. Wait for about 3 minutes for the grounds to settle, then savor your coffee. This summarizes the basics of a coffee workshop. 

My journey began with part-time work in a coffee shop, followed by my first gadget, the chemex, which dramatically heightened my curiosity. Now, I have more than 14 different tools for brewing coffee, two manual hand grinders, and a temperature-controllable kettle, making my life full of research and experiments. In addition, I AM NOT A BARISTA, I am involved in a non-profit organization that helps coffee people with projects and promote them. You are all invited to check its web page.

Happy International Coffee Day 2023!