AN OVERVIEW OF BASIC COFFEE KNOWLEDGE FOR YOU
Coffee is a familiar beverage anywhere in the world. To help you understand more about coffee, Vo Hung Coffee has compiled and summarized all the knowledge related to coffee. This knowledge provides you with an overview, serving as a basis for further in-depth research later. Despite our efforts, there may still be some shortcomings, which Vo Hung Coffee will continuously supplement and update. Please stay tuned.
The History of the Coffee Plant
The History of the Coffee Plant
From the 19th century, the first coffee beans were brought to Vietnam by the French. Since then, coffee plants have been grown from the North to the South, helping Vietnam become one of the coffee powerhouses. So, what is the origin of the coffee plant?
The Legend of the Coffee Plant
There is an interesting legend about the coffee plant as follows. A shepherd named Kaldi, while grazing his flock, accidentally discovered a type of red fruit and ate it. Afterward, Kaldi felt extremely invigorated and full of energy. He informed the local monks about it. Initially, they thought it was a forbidden fruit brought by the devil and decided to burn these beans.
However, that is just a legend. In reality, the coffee plant originated in Ethiopia (formerly known as Kaffa). The slaves captured from Ethiopia and taken to Egypt brought this fruit with them. It quickly became a highly favored beverage among the Egyptians. In the land of the pyramids, the coffee culture began to take root, and Egypt became the hub and center for trading coffee with the world through the port of Mocha (or Moka).
By the 18th century, the Dutch were the first to bring coffee outside of Egypt and plant it in Martinique. Subsequently, the French and Brazilians also brought this fruit back to their homelands. This facilitated the spread of coffee beans, leading to coffee being cultivated all over the world.
The Introduction of Coffee Beans to Vietnam
In 1875, when the French invaded our country, they brought the Arabica coffee variety from Bourbon to plant in northern and central provinces such as Xuân Mai, Sơn Tây, Quảng Trị, and Bố Trạch. However, the coffee yield in these regions was very low, only about 400 – 500 kg per hectare.
Therefore, they planted coffee seeds in many places, establishing plantations in the southern and Central Highlands provinces. Additionally, new types of coffee such as Robusta and Mitcharichia were also experimented with. From then on, coffee became the most common long-term industrial crop in Vietnam.
Coffee Growing Regions in Vietnam
In those days, the French colonists experimented with coffee at plantations across the country. Regions with favorable climates for coffee development were expanded, while those with low yields were eliminated. They also identified suitable locations for each distinct coffee variety.
Currently, Vietnam has many coffee-growing regions, including Thanh Hóa, Nghệ An, Hà Tĩnh, the Central Highlands, and the Southern region. However, in terms of climate conditions, the provinces in the Central Highlands are the most suitable for coffee cultivation. As a result, this crop is grown extensively here. High-yield, high-quality coffee plantations emerged, especially in Đắk Lắk and Gia Lai.
However, the best and highest-quality coffee varieties are often known to originate from Đà Lạt, Lâm Đồng province. The conditions regarding altitude, temperature, water source, and sunlight here are extremely favorable for leading coffee varieties like Moka, Robusta, and Bourbon to thrive.
Common Coffee Varieties in Vietnam
The tropical monsoon climate in Vietnam is very suitable for coffee plant growth, especially for high-quality varieties such as Arabica, Robusta, and Cherry.
Arabica Coffee
Arabica belongs to the Rubiaceae family, Coffea genus, and is known as 'cà phê Chè' in Vietnamese due to its small leaves and low stature similar to tea plants in Vietnam. Arabica originates from southwestern Ethiopia, and then it was introduced to Vietnam by the French. This was the first type of coffee planted in our country.
Within the coffee family, Arabica has many different varieties, and almost all of them are top-quality coffees. Some notable names include Typica, Bourbon, Moka, Caturra, Mundo Novo, Catuai, Catimor, and Moka.
Robusta
Up to 39% of the world's coffee production belongs to Robusta. This type of plant shares its origin with Arabica in Ethiopia but used to grow in wilder areas. Consequently, Robusta plants are taller, have more branches, and larger leaves compared to Arabica.
The flavor of Robusta is also not as highly regarded as Arabica in terms of purity and natural aroma. Therefore, its price is only half that of its counterpart. However, the outstanding feature of this coffee variety is its very high caffeine content, accounting for about 2 – 4% of coffee beans, while Arabica only contains 1 – 3%.
Learn more: Cà phê Arabica và Robusta – 11 Điểm khác biệt giữa hai dòng cafe
Coffee Cherry
Cherry, also known as Chari coffee or Mit coffee, originates from Ubangi Chari, near the world's largest desert, the Sahara. Because of this, this type of plant has relatively large characteristics, with thick stems and large leaves to store water and thrive in dry climates.
The Chari fruit is larger than other varieties, but its yield is not high. In terms of flavor, it is also not highly rated compared to Arabica or Robusta, so it is rarely grown in our country today.
In addition to the mentioned coffee varieties, there is also the mutation line called Culi, which combines the flavors of Arabica and Robusta.
Coffee Flowers
The structure of coffee flowers is white and consists of 5 petals, not blooming individually but forming large clusters. Coffee flowers have a very short pollination time, about 3 to 4 hours, but can last up to 4 days.
Unlike many industrial plant varieties in Vietnam, coffee flowers bloom multiple times a year. However, the frequency depends on weather conditions and climate. Nowadays, there are many methods to naturally stimulate flower blooming to increase coffee yields.
Coffee flowers only sprout in low-temperature conditions or after a prolonged period of drought, typically about 2 to 3 months. Usually, seasons with alternating hot sun and rain after a few months will help coffee flowers bloom at the right time, resulting in higher yields.
Understanding the flowering principles of coffee flowers enables growers to provide suitable water and nutrients to increase seasonal productivity. However, it's essential to avoid adverse weather conditions, prolonged rain, and especially salt mist, as they can cause coffee flowers to rot, significantly reducing yields.
Structure and Composition of Coffee Fruit
Coffee Fruit Structure: A coffee fruit comprises six main parts: the stem, fruit peel, pulp, parchment, silverskin, and the seed, also known as the coffee bean.
Stem: The stem connects the fruit to the tree branch and needs to be flexible. This helps prevent the fruit from falling due to natural external forces while remaining brittle enough for easy harvesting.
Fruit Peel: This is the outermost layer of the coffee fruit, serving to encase and protect its inner parts. When unripe, the coffee peel is green, gradually transitioning to red or yellow as it ripens, depending on the coffee variety. The peel of Arabica varieties is softer and smaller compared to Robusta and Chari varieties.
Pulp: The pulp of the coffee fruit has a mildly sweet taste and is edible. In the production of Civet coffee, civets eat and digest the pulp, excreting the seed. Arabica pulp is sweeter and softer, whereas Chari coffee has thicker pulp.
Parchment Layer: This is a relatively hard shell after being dried to protect the coffee bean. After harvesting coffee, the outer husk is removed, leaving behind the pulp and oily residue, revealing only the parchment and the bean inside. During processing, this parchment layer is also removed and can be used as fuel or for excellent composting.
Silverskin: The silverskin is a very thin and soft layer that wraps around the coffee bean. Each coffee variety has a different silverskin color. Arabica coffee has a white silverskin, Robusta coffee has a light brown silverskin, and Chari coffee has a light yellow silverskin.
Coffee Bean: This is the component that gives value to the coffee tree. The coffee bean is divided into two parts: the hard outer layer containing small cells with oil and the inner part containing larger and relatively soft cells. Except for rare cases where a coffee bean may have only one or, uncommonly, three parts, the majority of coffee beans have two equal parts.
Chemical Composition of Coffee Fruit: In a complete coffee fruit, there are many different components, each crucial for imparting flavor to the coffee bean.
Fruit Peel: The fruit peel contains many Anthocyanins, giving ripe fruit a red color. Additionally, the fruit peel contains various substances such as caffeine, alkaloids, tannins, and many other enzymes.
Pulp: The pulp layer mainly consists of mucilage and soft cells. This part contains a high amount of sugar, giving the coffee fruit its sweetness. Additionally, it contains Pectinase, which contributes to the delicious taste of the coffee bean.
Parchment: As it surrounds the coffee bean, the parchment layer also inherits a significant amount of caffeine, up to 0.4% of the weight of the coffee fruit.
Coffee Bean: In fully ripe coffee beans, the water content is approximately 10 – 12%, followed by 10 – 13% Lipids, 9 – 11% Protein, 5 – 10% sugars, and 3 – 5% starch. Each coffee variety has a different chemical composition, contributing to its distinctive flavor. Furthermore, optimizing processing also greatly improves quality.
Characteristic Compounds in Coffee Beans:
Water: In the drying process, coffee must have 10 – 12% bound water. After roasting, this figure decreases to around 2 – 3%. If the water content is higher, preservation becomes significantly more challenging, leading to mold and affecting quality.
Lipids: Of the 10 – 13% Lipids in coffee beans, approximately 90% is oil, with the remainder being wax. Lipids are responsible for the aroma and richness of coffee. After processing, only a small amount of Lipids remains on the coffee grounds, which is excellent for skincare.
Proteins: Although protein content in coffee is low, it contains many beneficial amino acids. When roasted, these proteins burn and produce a characteristic aroma and taste, contributing significantly to the flavor of coffee.
Minerals: Mineral content in coffee beans accounts for 3 – 5%, primarily including Magnesium, Potassium, Nitrogen, Phosphorus, Chlorine, Iron, sulfur, and others. Good-quality coffee usually contains minimal mineral content as they can negatively affect coffee flavor.
Caffeine: This compound is what distinguishes coffee from other fruits and seeds. Caffeine is the source of the benefits of drinking coffee, promoting relaxation and energy. The caffeine content varies between coffee varieties, with Robusta containing the highest levels.
Coffee Processing Methods: The processing method significantly affects coffee quality. Currently, three common coffee processing methods are dry processing, wet processing, and honey processing. Each method has its advantages and disadvantages.
Dry Processing: This method involves drying the whole coffee fruit under sunlight and wind immediately after harvesting. It is easy to perform and requires minimal effort. However, its significant disadvantage is that it prolongs the drying time, making the coffee beans more susceptible to mold from the inside. Especially in adverse weather conditions where drying is not possible, mold is likely to occur, leading to lower coffee quality.
Due to the aforementioned disadvantages, dry processing is rarely used, especially for high-quality coffee varieties like Arabica.
Wet Processing: For high-quality coffee varieties, wet processing is preferred to ensure the best quality. Although this processing method requires more effort, the resulting value of the finished coffee is significantly higher.
Immediately after harvesting (only ripe beans are harvested, and the amount of unripe beans should be minimized), the coffee cherries are pulped. Then, they are soaked in water to ferment, removing the outer mucilage layer, and the remaining beans are then fermented. The fermentation process is complete when the parchment layer becomes slimy and free from mucilage.
Finally, the coffee beans are washed and then dried. Afterward, the outer parchment layer is removed, resulting in the finished coffee beans.
The drying process is meticulous, avoiding direct contact with the ground to prevent moisture absorption. Even drying is crucial, and the process is considered complete when the beans can be bitten without breaking, requiring considerable experience from farmers.
Honey Processing: This processing method is similar to wet processing. However, instead of removing all or most of the mucilage before drying, some or all of it is retained. This results in coffee beans with a dark brown color resembling honey, hence the name "honey processing."
Coffee processed this way retains more sweetness and enhances flavor when enjoyed.
Roasting coffee beans is essential to extract their full flavor potential. Unlike grains or nuts, coffee beans cannot be consumed directly; they must be brewed into a beverage. Roasting helps unlock the flavors and aromas locked within the beans.
During the roasting process, various chemical compounds within the coffee beans undergo transformations. Compounds such as caffeine, lipids, and proteins are affected, leading to the development of unique flavors, aromas, and bitterness. These transformations are crucial for creating the characteristic taste and aroma of coffee.
Without roasting, coffee would lack its distinctive flavor profile, including the rich aroma, bitterness, and delightful aftertaste that coffee enthusiasts enjoy. Therefore, roasting is an essential step in the coffee-making process, ensuring that coffee beans reach their full potential in terms of taste and aroma.
Furthermore, roasting coffee also facilitates the grinding process by removing most of the water content inside the beans, leaving only the water within the fats and waxes. Therefore, when brewing ground coffee after roasting, it becomes easier to extract its flavor.
The transformation of coffee bean components during roasting begins at around 100°C and continues until reaching approximately 240°C. During this heating process, various components in the coffee undergo transformation:
At 100°C The internal moisture begins to evaporate, causing the coffee beans to shrink.
From 0 to 150°C Moisture continues to be lost, and the coffee beans start to change color to a light yellow. The shrinking process continues, accompanied by the emergence of a fragrant aroma.
From 150 to 180°C If maintained at 150°C, the coffee beans will transition from light yellow to light brown. Heating up to 180°C is required for a more fragrant aroma. The shrinking process ends, replaced by the expansion of volume as the internal components begin to decompose.
From 180 to 200°C During the heating process from 180 to 200°C, the coffee beans have expanded fully, releasing a strong aroma, and the internal components can be easily ground into powder. However, grinding at this stage may not yield the best quality and lacks acidity.
From 200 to 210°C The coffee beans begin to expand to the point of bursting, emitting smoke and spreading a fragrant aroma.
From 210 to 230°C The coffee beans continue to expand due to the release of carbon dioxide and burst more frequently.
From 230 to 240°C At this stage, the beans become dark brown, emitting a strong aroma, and the internal components are transformed to achieve the best flavor. This is the most suitable stage for grinding and brewing.
Types of Finished Coffee Products There are many different methods of coffee processing, resulting in various types of finished products, each with its own advantages and disadvantages.
Ground Coffee This type of coffee is roasted and ground into powder form, requiring users to brew it using a machine, filter, or other utensils, which can be time-consuming. However, this is the best way to enjoy delicious and healthy coffee. There are three types of ground coffee available on the market:
Pure Coffee The name says it all. This type of coffee is made from 100% natural coffee beans, without any presence of additives like peas, corn, or cereals. However, during the fermentation process before roasting, coffee beans may be fermented with butter or wine to create their distinctive aroma. The advantage of pure coffee is that it retains the most distinctive characteristics of coffee, and those who are connoisseurs and enthusiasts of this type of bean will prefer to use pure coffee.
Pure Coffee is also pure coffee, meaning it is made from 100% coffee without any adulterants. However, if pure coffee is not closely monitored for quality, clean coffee is the complete opposite. From planting, the clean coffee beans are checked for soil conditions, irrigation water, and nutrients—everything must be completely clean and certified. In addition, the processing and storage processes must meet strict standards. The roasting and grinding process must ensure no adulteration or flavoring agents are added.
Black Coffee The term "Black" in black coffee does not refer to a specific type of coffee like Arabica or Robusta; it originates from the processing method. Similar to pure coffee or clean coffee, black coffee is not mixed with any additives during roasting and grinding. However, the term "black" also denotes the way this coffee is enjoyed—simply roasted, ground, and brewed with water. This method of enjoying coffee does not involve mixing with any other substances like sugar, milk, or cream. This way of drinking allows you to fully enjoy the coffee flavor, but it may be challenging for some people to drink.
Instant Coffee Realizing that coffee powder takes a lot of time to prepare, manufacturers have come up with a way to help consumers enjoy coffee more conveniently. During production, they pre-mix flavorings and additives into the coffee powder to achieve the desired taste. Users only need to add this powder to boiling water, mix it, and they can enjoy it in just 30 seconds—a quick and convenient way to make a delicious cup of coffee.
The advantage of instant coffee lies in its convenience and speed, as the flavor has been pre-prepared and measured to provide a consistently enjoyable cup of coffee at any time. However, a significant downside is that the added flavorings may detract from the taste of pure coffee. Additionally, these additives can contribute extra calories from sugar and milk, which may not be beneficial if consumed in excess.
Coffee Water
If even instant coffee is too time-consuming or unavailable, pre-made coffee water is incredibly convenient. Similar to instant coffee, it's ready to drink with just a twist of the cap.
The advantage of this type of coffee is its speed and convenience. However, the exact ingredients are often unclear, and there may be significant energy sources from sugar, milk, or high levels of preservatives to extend the product's shelf life. These factors may not be optimal for regular consumption and could impact one's health negatively.
Moreover, the amount of pure coffee in coffee water is minimal, just enough to provide some flavor but not comparable to brewed coffee.
Coffee Brewing Methods
Coffee is the most popular beverage worldwide, and the method of brewing varies depending on cultural preferences and individual tastes. Some famous brewing methods include:
Espresso, Cappuccino, and Latte from Italy
These are arguably the most beloved coffee drinks globally. Espresso uses the finest coffee beans, resulting in a smooth texture and excellent color. Brewing espresso with milk according to specific standards creates Cappuccino and Latte.
Buna Coffee in Ethiopia In the homeland of coffee, people take great pride in this beverage because all types of coffee originate from a goat herder in their land. Therefore, the way of enjoying coffee here is somewhat different. Ethiopians use coffee (locally called Buma) brewed with salt or butter instead of sugar and milk like in other countries.
Turkish Coffee (Turk Kahvesi) This brewing method is extremely simple; people just need to put coffee grounds into water and boil it on the stove until it reaches the desired aroma.
Danish Coffee (Kaffe) Danes prefer to drink pure coffee with cream or fresh milk without mixing with any additives. This brewing method is quite similar to Italian coffee with cream.
Irish Coffee This is a special way of brewing coffee for the Irish. They mix hot coffee with a little Irish Whiskey, sugar, and a bit of whipped cream. This drink is perfect for warming up on cold winter nights.
Most notably, Vietnamese Drip Coffee: This is the most common brewing method in Vietnam. Almost every household has a drip filter to brew coffee, and in eateries, the image of the drip filter has deeply ingrained in the minds of many people.
Enjoying Coffee
Coffee Flavor The flavor of coffee is something quite subjective, relying on the perceptions of individuals. Each type of coffee carries its own distinctive flavor, and the choice depends on each person's preference.
Arabica coffee has a beautiful, rich brown color, smooth and creamy texture. When enjoyed, a high-quality Arabica coffee will have a distinctive bitter taste, a delicate and seductive aroma, along with a hint of acidity or fruity flavor to balance the bitterness.
Robusta coffee is also bitter but has a gentle aroma, not as acidic but sweeter than Arabica.
We can also combine these two flavor profiles together with a neutralizing agent like cocoa or chocolate with a specific dosage to enhance the flavor experience.
Typically, the formula used is: 30% Arabica coffee, 40% Robusta, and the remaining 30% a neutral or cocoa coffee. However, if you prefer to enjoy coffee in your own way, you can completely adjust the formula to suit yourself.
Benefits of coffee
Coffee contains a lot of caffeine, which has many effects on the body, and at the same time, beneficial minerals and compounds also provide many benefits to regular coffee drinkers.
Speaking of the beneficial effects of coffee, we can mention a series of items such as: Fighting drowsiness, uplifting the spirit, feeling more relaxed, preventing cancer, aging, prolonging lifespan, beautifying, weight loss,... And many other benefits.
However, these benefits are only obtained when consumed in moderation, typically from 2 to 3 or 5 cups of coffee per day. If coffee is excessively consumed, it can also lead to regrettable consequences such as insomnia, caffeine-induced anxiety, caffeine addiction, increased blood pressure, and more.
Therefore, it's important to know how to use coffee in appropriate doses and timing to maximize its benefits while minimizing any unwanted effects.
Coffee Storage
To enjoy a truly delicious cup of coffee, all processes from cultivation, harvesting, processing, roasting, grinding, storage, and brewing must be done correctly. Among them, storage is an extremely important process because coffee, at this point, is in the form of grounds or as a finished product, making it susceptible to spoilage.
Storing Coffee Grounds
Coffee grounds can be stored for a maximum of 2 years from the time of roasting and grinding if done correctly. Especially within the first 14 days after grinding, they should be placed in airtight packaging, kept in dry places, and protected from moisture to prevent the loss of caffeine and flavor.
If you grind your own coffee, avoid storing it in plastic bags as they are prone to mold. Instead, you can store coffee grounds in glass jars with airtight lids for better moisture protection. Ideally, store them in high, dry, cool places and away from direct sunlight.
Coffee can also be stored in one-way valve bags or vacuum-sealed containers. This is an excellent preservation method that prevents outside air from entering and accelerating the natural oxidation process of coffee.
Note when storing ground coffee: Coffee is best stored at temperatures between 20 - 25 degrees Celsius. This temperature range is sufficient to prevent the internal components of the coffee from deteriorating.
Avoid storing coffee grounds in the refrigerator, especially in the freezer compartment, as low temperatures can greatly affect the oils and fats, causing them to solidify and degrade. Additionally, the aroma and flavor of the coffee will also diminish due to the interference of odor-absorbing ions in the refrigerator.
Knowledge about coffee is endless, and to fully understand and appreciate this beverage from its cultivation, harvesting, roasting, grinding, brewing, to storage, you need to spend a considerable amount of time exploring. However, with the comprehensive knowledge provided here, it is hoped that you have gained a better understanding. When you enjoy a cup of coffee, try to appreciate the essence of the sunlight, the breeze, and the sweat of those who have worked hard to bring it to you.