coffee beans

Coffee – Origin and Varieties

When going to the store to buy coffee, many people face the dilemma of what kind of coffee they should buy. They are exposed to numerous coffees, such as Vietnamese, Ethiopian, Java – Indonesia, or Brazilian, and the selection of different roast levels. Sometimes we buy one based on marketing and end up disappointed at the final result.

Maybe looking at coffee and answering a few questions about coffee and what is happening during the brewing will help us make more informed decisions.

What is coffee

The berries are harvested from species of Coffea plants, which can reach heights of up to 9 meters and longevity up to 100 years, but the actual production period is between 5-20 years.

The fruits of the coffee shrub are known as coffee cherries, and each cherry generally contains two coffee seeds or beans. The beans look like real cherry pits, and only about 5% of the cherries have one seed, called peaberries. The fruit is small, like an olive, and green turns red during ripening.

There are about 50 species of coffee beans, but only two of them are the main ones, Coffea arabica and C. Canephora, and they supply almost all of the world’s consumption.

Arabica is wider spread than Robusta (the main variety of C. canephora), and it has a milder and more aromatic aroma than Robusta. At the same time, it needs specific climate conditions to grow and extra care. The ideal conditions and some of the differences for both coffee varieties are as follows.

Subtropical climateSubtropical climate
Higher elevations – 2,000–6,500 feet — 600m–2,000mSee level – 2000m
Needs lots of moisture, sun, and shade. More vulnerable to pests and diseases.Hardier plants, better resistance to climate,
weather conditions, diseases, and heat.
It has a different shape – prolonged formRound shape
Milder taste2 times more caffeine – often producer’s choice for espresso. Selection of a blend for inexpensive coffees.
Coffee Varieties

History of Coffee

Coffee origins trace back centuries to the region of the Ethiopian plateau. As the legend goes, the goat herder Kaldi first discovered the potential of these beans. After eating the berries from a particular tree, he noticed that his goats became so energetic that they did not want to sleep at night.
Kaldi told the abbot of the local monastery about his observations, and he decided to make a drink with the berries and found that it kept him late in the night. The abbot shared his experience with the other monks at the monastery; they’ve also tried it, and coffee cultivation and trade began.
By the 15th century, coffee was already popular in South Arabia, and about one hundred years later, coffee was already known in Persia, the Middle East, and Turkey. In that part of the world, coffee houses became important social centers, places for discussion, and social gatherings.

Coffee expansion soon found its place in Europe, even though it was initially looked at with suspicion and declared the “bitter invention of the Satan” – Venice, 1615. Even the pope himself, Pope Clement VIII, had to express his opinion about the “devil’s liquid.” After he tried and liked it, he declared that it tasted so good, it couldn’t be Satan’s invention, so he gave the coffee papal’s approval.

Bu mid-17th-century coffee houses started popping up in Central and Western Europe, becoming part of everyday life.
Coffee’s popularity continued to spread; the Dutch were persistent in their cultivating efforts initially in India and later in Indonesia – known as the island of Java.

The New World

Around that time, coffee was making its way to the New World. By the mid 17th century, coffee was already in New Amsterdam – New York, but it did not become popular until the late 1700s, after the revolt against the high tea tax imposed by King George III.

Gabriel de Clieu, in the early 17th century, brought the seeds to Martinique from France, whereby at the end of the century, they already had close to 20 million trees, from there it spread around the Caribbean and South America.

Another story says that the governor Maranhão e Grão-Pará in northeastern Brasil sent Francisco de Mello Palheta to settle a dispute between French Guiana and Dutch Guiana. The real reason was to obtain coffee seeds from French Guiana, and thanks to his good looks, he did. The governor of French Guiana had already refused his request to get some sources. Still, his wife was charmed by senior Palheta, and she was able to sneak some seeds in a large bouquet, and the Basilian billion dollar coffee industry was born.
By the end of the 18th century, coffee had become one of the world’s most profitable export crops.

Bean Belt

map of coffee types
R- robusta A- arabica M- both
source – public domain

Coffee Bean Belt is a particular geographic region with a suitable climate for growing coffee, and it is known as the Bean Belt region.
In general, the decision to produce Arabica or Robusta is determined by the coffee trees’ latitude. Within the Bean belt, the coffee produced in different areas has a distinctive flavor profile particular to that region, which makes it more exciting to find the perfect brew.

These days, the demand for coffee is comparable with the market for oil demand, and currently, coffee is the top ten most sought commodity in the world.

Can you imagine a world without coffee?

How coffee beans become coffee

After coffee cherries are picked up and bought at the processing facilities, they undergo a few different process steps before the coffee is ready to be shipped.

Extraction process

The two main extraction processes produce different flavor profiles.

Washed method – fruits are washed with water, everything is removed except the beans. After washing, they are left to dry for about 30-40 days. The resulting taste is a pure bean with a lighter, more tea-like floral aroma.

Natural method – there is not much human interaction in this process.

The cherries are left outside for 10-30 days, and during that time, they slowly start to decay. That’s a normal process, and what is happening is that the fruits are undergoing fermentation – a bacterial process that influences the taste of the beans.
The next step is to remove the skin and the pulp from the beans. That step is similar to the washing process, but here the beans have additional flavors such as sweetness and creaminess caused by the fermentation.

During the natural fermentation process, the producers control fermentation development by using open tanks, different vessels, and techniques to contain the coffee.

Based only on the extraction process, if one desires a sweet and less intense cup of coffee, choosing the natural extract method is the way to go.

Anaerobic-environment fermentation

There is another fermentation method called anaerobic-environment fermentation, where some producers attempt to control the oxygen level of the process.

The vessels in which the coffee cherries are fermented don’t contain any oxygen: The oxygen is removed at the beginning of the process. The holding tanks have a valve that stops the CO2 from seeping in and allows the increased oxygen level from fermenting to be released.
Some producers use this type of fermentation to add additives like tropical fruit or molasses to the coffee cherries to add additional flavor.
This process is called anaerobic impregnation.
During that fermentation, a naturally fermented coffee-cherry liquid is produced with a high level of alcohol content, and it can be served as an excellent addition to coffee tasting.

Coffee Origins

Coffee origins are an essential part of the flavor profile. By origins, I mean at what altitude, not just geographic location, the trees are grown.

For instance, coffee grown in a low altitude environment like Indonesia has a high growth rate and lots of oxygen, and the beans will be less dense than those grown at high altitudes. Predominant flavors are – earthy, sweet, low acidity, and have a more bland character.

Coffee grown in high-altitude environments, 4000-6000 feet above sea levels like in Kenya or Ethiopia, doesn’t have access to the same level of CO2 and, therefore, less energy. That lack of oxygen leads to a process called anaerobic respiration. This process causes the formation of lactic acid, which imports more flavors into the coffee – citrus, chocolate, vanilla, spice, nuts, creaminess, and balanced bitterness.

So far, we have covered two components that influenced the coffee flavor, fermentation, and origin, and based on that, we can choose what type of coffee we would rather have. Let’s say I’d like to have light, fruity and creamy flavor in my coffee; in that case, I will go with beans that went through a natural process and higher elevation.


The roast is a scale of roasted levels, from light to dark, and it all depends on how the beans are cooked in the oven.

The roasting process allows the cooking of the natural flavors of the bean to be extracted.
Roasting coffee causes the sugars, fats, and starches contained in the bean to emulsify, caramelize, and release. The resulting coffee oil from the roasting contributes additional flavor to the coffee.
The roasting process starts with lower heat, and gradually, it increases to 390-480Fº, which allows the heat to penetrate the center of the bean slowly.

The coffee beans start changing color, and as cooking continues, the beans begin swelling. At some point, loud cracking noise can be heard; the sugars start to caramelize, and the coffee is considered roasted, but it is still at level one.

As the cooking continues, the color darkens, the sugars continue to caramelize, and usually, during this step, the roasting is stopped before the second crack noise is heard. At this point, we have a dark roast, and if the cooking continues, all the sugars will be caramelized, leading to a very bitter taste.

The next step is called degassing.

The degassing phase is critical, and coffee production should not proceed to the next steps until all of the CO2 has been released. The usual wait time depends on the coffee, and it can be from a few hours up to 24h for most of the brands.
If you decide to brew coffee straight from the roaster, you will be consuming elements that will make the coffee seem woody, bitter, and flat.

roast levels
Roast Levels

Roast Levels

Roasting is an integral part of forming the final flavor profile of the coffee beans, as different chemical compounds – flavors are extracted at different times.

Lighter roasts are usually more acidic than darker roasts.
Darker roasts have a fuller flavor but less caffeine than light roasts.
Over-roasted coffee has a smoky, burned flavor, probably not that desirable in the coffee.

Note: Coffees with the same roast might have different flavors from different origins.

Light Roasts
Cinnamon, Half City, Light, New England
The bean is light brown. The flavor is floral, slightly acidic, and bread-like, similar to toasted grain.
Some sour tones may be present on the coffee, and the coffee’s body will be minimal.
Cinnamon Light is the lightest one with noticeable sour and bread notes.
Cinnamon has hints of toasted grain, and there are distinctly sour acidic notes. New England or Half City — the beans are darker than the Cinnamon.
The taste is still sour but not so bready.

Medium-Dark to Dark Roasts
Full City, Light French, Viennese
Medium-dark brown beans. Full City roasted beans have some coffee oil on the surface. They have hints of chocolate,
caramel aromas, and a hint of spice. Full body. Light French or Viennese is slightly darker than Full City.
Dark/High Roasts
French, Espresso, Turkish
The beans are very dark brown. French roasted beans are shiny with an oil coating on the surface and lower acidity.
Some of the complex flavors of lighter roast coffee are reduced and/or destroyed with dark roasts. These flavors are replaced by bittersweet, tangy, dark roasted flavors that include chocolate and caramel notes.
Dark/High Roasts
Italian, Dark French, Spanish
Spanish is the darkest roast of all. The coffee beans are almost black, and it has nuances of charcoal aroma,
as nearly all of the sugar in the beans has been caramelized. The bean has a more robust burnt flavor, and the acidity is almost gone.

Maillard Reaction

Let’s take a glance at the chemical process during the roasting. We will see that the process responsible for sugar caramelization and some other chemical reactions is the Maillard reaction.

In this process, the sugars are combined with the amino acids, and as a result, new flavors such as caramel and chocolaty aromas are introduced.
During the dark roast, the Maillard reaction is more prolonged; therefore, this type of roast will have more savory tones, but at the same time, we will have less real bean taste.

Generally, we can summarize the roasting process as:
At the beginning of the roast, the dominant flavors are that of the bean – floral and acid. We get new flavors such as caramel, fruit, chocolate, and some spicy ones with longer roasting. The more we continue with the roast, the more the coffee taste changes to a more bitter and harsh charcoal taste.
At this point, based on the extraction method, origin, and roasting scale, we can decide on the type of coffee we might buy.

If I want to have coffee that tastes sweet, not too acidic, or too bitter, I will go with the natural method, high altitude, and medium roast.
If I want a dark cup of coffee, I might go for washed, low-altitude, and dark roast.

Flavor to Roast
By Peter Baskerville

Coffee Grinding Options

Deciding on the coarse level of coffee grinding is one essential step towards the expected quality of the final brew. Grinding aims to break the beans and expose them to flavor extraction during the brewing process.
We increase their surface exposure and extract all the desirable flavors into the water by turning them into smaller particles.

If we look at what is in the cup of coffee, we might be surprised that more than 98% is water.
That’s why finding the right size will significantly determine the quality of the final brew.

Here are some suggestions on finding the right timing, equipment, and coarseness for coffee grinding.
If the ground coffee is too fine for the brewing method being used, the final result will have a more bitter taste, and if the coarseness is too large, we will potentially have an under-extracted flavor.

Decide what brewing method you want to use that will help determine the coarseness level. Use a good quality grinder; cheap ones will most likely produce uneven grinding particles. Ideally, grind the beans right before brewing. Always keep the grinder clean.

Coffee Grinders

Coffee grinders: If money is not the primary concern when buying a coffee grinder, go for Burr Grinders.
There are two types: Wheel Burr and Conical Burr will grind coffee evenly and not overheat and affect the flavor.

Many people prefer the Conical Burr as it is not messy and less prone to clogging.

Coffee old grinder
Old Style Coffee Grinder

Caffeine – The Trickster

Caffeine is a methylxanthine alkaloid that occurs naturally in tea, coffee, nuts, or leaves of several plants native to South America and East Asia.
It is a central nervous system stimulant structurally related to adenosine, which has a similar molecular structure.

To understand the importance of their relationship and understand how caffeine works, let’s see first what adenosine does.
Adenosine is a central nervous system neuromodulator that has specific receptors. When activated, the neural activity slows down, decreases the adrenaline, and makes you feel sleepy.

According to an article posted on the McGill University website, “caffeine acts as a blocker to the adenosine effects. Activating numerous neural circuits causes increased production of adrenaline, improves the awareness, and gives the body the feeling of “more energy.”

Another independent study, published in Physiology & Behavior, 2017, came to a similar conclusion about the caffeine effects on our nervous system.

the increased anxiety-like behavior and depleted cognitive functions under stress conditions were improved …

Physiology & Behavior

Caffeine may also have a positive effect on slowing down and protecting cognitive decline. In 2017,  Boukje van Gelder and her colleagues reported the results of a 10-year study on the coffee effects on 696 men. They found that men who drank coffee had less cognitive decline than those who didn’t. The researchers observed the most significant impact on people who drank three coffees a day compared to one who had less or more coffees per day.

In a recent article, Dr. Uma Naidoo, a nutritional psychiatrist, a faculty member at Harvard Medical School, also mentioned a few key ways coffee can support the brain:

According to her, not every coffee substance is helpful. For example, unfiltered coffee contains natural oils called diterpenes, which increase LDL cholesterol levels — potentially resulting in the thickening and hardening of the artery walls in the brain. Choosing dark roast freshly ground coffee may reduce the unwanted chemicals in your brew.

Based on the studies mentioned above, the benefits of having caffeine don’t mean we have to go out there and drink coffee all day long. Overindulging in caffeine-laden drinks can possibly harm the body, causing increased adrenaline and cortisol levels.

Overexposure to stress hormones, including cortisol (the main stress hormone), can cause trouble within almost all body processes, increasing the risk of weight gain, sleep problems, anxiety, and inhibiting insulin effectiveness which makes your blood sugar (glucose) levels rise.1

Moderation is key to everything, I guess, so the question is how many coffees is suggested to have? There are many variables to be considered, but generally, the recommended amount of coffee is two a day and no more than four. Once in our body, caffeine is absorbed within about 45 minutes after consuming and peaks in the blood anywhere from 15 minutes to 2 hours. That will depend on the person’s caffeine tolerance, some people can drink coffee all day with no side effects, but the majority will feel some jitters after the fourth or fifth coffee.

I think it is also essential to understand; that caffeine does not give us extra energy; it fools us and stops the brain from thinking, “I’m sleepy, I’m tired, I need a nap.”

Caffeine Effects

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Adenosine and Caffeine Effects

Caffeine levels in certain products



Finally, we get to brew some coffee, but wait, what method should I use? What about the water to the coffee ratio? I want my caffeine. OK, go ahead and have a cup of coffee.
Now, let’s see if these previous questions make any difference in the final brew.

Bean Chemistry

There are two parts to a roasted bean – solubles and non-solubles.

Screenshot from 2021 03 31 11 56 39

Non-solubles – give shape structure and are left behind after brewing.

Solubles – all the extractables provide color, aroma, and flavor.

The percentage of the solubles (color, texture, flavor) in a cup of coffee depends on the yield and concentration of the brew.

Soluble yield is focused on the type of flavors extracted. For instance, the bitterness is extracted later in the process, and different desirable aromas are pulled at other times within the brewing process. Let’s say we have 3 coffees brewed for 2-5-10 min. The first might have an underdeveloped- weak flavor, the second – is just right, and the third will have lots of bitterness.

Time is also one important factor to consider, among others.

Soluble concentration is about adjusting the amount of coffee needed, hence the number of materials required.

Stronger coffeemeans we have higher compound concentration, keep the water the same, less coffee
Weak coffee – no flavor
means we have a lower compound concentration – increased amount of coffee – increased solubles concentration,
keep the water the same, increase the infusion time – higher soluble yield
Bitter coffeewe might have to use less water – shorter brewing time, and less coffee
Flavor Influencing Factors

Time, water, and quantity are important not because they create the best coffee, no such thing, but because they can adjust the brew to our liking.

There are other ways to measure these variables, briefly mentioning some of them. Check Martin Lersch’s detailed posting on his blog for more detailed information on these parameters.

Parameters influencing the final brew

BR – Brew ratio is measuring the amount of water to coffee. The weight of the coffee X 16.7=Water needed.

The multiplier can vary between 14-17. if we need to know how much coffee we need for our brew, we divide – water volume / 16.7=coffee.

TDS – measuring total dissolved solids – solubles in the final product. Typically there are 1.2-1.5% of total dissolved solids, which means that only 12-15 grams of extracted solids out of 60 g per 1000 ml.

EE – Extracted yield – calculated from the amount of solids extracted from the coffee grounds.

EEY – Effective extraction yield – used to measure the effectiveness of extraction of solids in the brew. That will also depend on the choice of brewing method.

PSD – particle size distribution is about Grind size. Particles of the ground coffee have different sizes; it is accepted that they should be smaller than 100µm. The exaction process takes place on the surface of the particles smaller than 100µm, which means any particles bigger than 100µm are not part of this process and become wasted coffee.

The mineral content of the water can influence the brew as well.

Water temperature – can lead to different flavor profiles. Different temperatures extract various chemical compounds, and the optimal temperature is around 93º-99ºC.

  • For instance, if we do cold brew, the final flavor is not so sweet or bitter, as the extraction of the compounds depends on the water temperature.

Methods of Brewing

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Immersion method

There are different methods of brewing coffee; some of them need more manual control – Pour over and Immersionsteeping, and others not so much – percolation, vacuum filtration, and pressurized infusion.
Is one better than the other one? Not sure, but let’s see some of the differences between the manual ones as we have more control over them.

The French press is using the immersion method to brew coffee.

The preferred grind is a coarser coffee ground, as the process involves a longer brew time. Adjusting the course grind to finer will make the brew fills stronger, and if it is too harsh, change it to a coarser grind.
This method allows coffee and water to stay together for a longer time, around 4-5 minutes, which extracts every single soluble from the coffee in the water. It results in an oily brew with a good body and thick texture.

Water temperatureBetween 95ºC – 210ºF for a lighter roast and 90ºC – 195ºF for a darker roast
The ratio of the coffee1:16, coffee to water, coffee by weight to water, 60g coffee to 1000ml water – 60/1000=16.7, adjust if needed for smaller volume
Brewing time varies 4-5 minutes

Pour over method

mentatdgt 1383851 2 edited 1 scaled

It uses medium-coarse to medium-fine grind.

This method is entirely different. After you place the coffee in the filter and pour the water, the water goes through the coffee right away, and it extracts only the available coffee components. The interaction of the coffee and the waters last only for short moments. As opposed to longer time in the full immersion method.
The speed of coffee extraction is faster, but if one is pouring the water too fast, it might extract the flavor too quickly and potentially brew inferior coffee.

Note: A critical step with this method is to wet the beans for 20-30 sec before pouring the water, which will allow the coffee beans to degas the trapped CO2.

Water temperatureBetween 95-98ºC – 210ºF for a lighter roast and 89-90ºC – 193ºF for a darker roast
The ratio of the coffee1:15 – 1:17, coffee to water – similar to the immersion method
Brewing time variesLighter roast is 3-4 minutes, and for a darker roast is 1.30-3 minutes.

Another note here is when we pour water over the coffee, we have to make sure the filter is not clogged and the water doesn’t go over the sides of the filter.
If you are after a pure bean taste, go for Pour-Over. If you’re after a more complex, thicker texture, probably the Immersion one is a better option to go.

Instant Coffee

Instant coffee is a fast and easy way to have a cup of coffee. In short, it is made from brewed coffee that has had the water removed. To make instant coffee, simply add some water to hydrate the powder.

  • The first “instant coffee” called coffee compound was made in Britain in 1771 and had a patent granted by the British government.
  • During the Civil War in 1851, cakes” of instant coffee were shared in rations to soldiers.
  • David Strang from New Zealand invented and patented instant or soluble coffee in 1890.
  • The first successful method of creating a stable soluble coffee powder was invented by Japanese-American chemist Satori Kato who exhibited it at the Pan-American Exposition in 1901.

Instant coffee is usually made from Robusta beans. One of the reasons for Robusta being the bean of choice is that it is easier to grow and has a higher caffeine content than Arabica bean. An essential consideration is the loss of some caffeine while making instant coffee.

The beans are roasted, finely ground, and then brewed to remove water. The solution is then dried by one of two methods:
Freeze drying or Spray drying, and what is left is an extract of crystallized coffee grounds, which are rehydrated before use.

  • Freeze drying2
    1. The coffee extract is chilled to a slushy consistency at about 20°F (-6°C).
    2. The prechilled slush is placed on a steel belt, trays, or drums and is further cooled in a series of steps, until it reaches a temperature of -40-(-50)°F (-40-[-45]°C). Quick cooling processes (taking 30-120 seconds) result in smaller, lighter colored products, while slower processes (taking 10-180 minutes) generate larger, darker granules.
    3. The slabs of ice are broken into pieces and ground into particles of the proper size for the drying step. The particles are sieved to ensure proper sizing, and those that are too small are melted and returned to the primary freezing stage.
    4. The frozen particles are sent into a drying chamber where, under proper conditions of heat and vacuum, the ice vaporizes and is removed.

  • Spray drying3
    1. Cooled, clarified liquid concentrate is sprayed through a nozzle at the top of a drying tower. The tower is at least 75 ft (23 m) tall.
    2. The air that has been heated to about 480°F (250°C) is blown downward through the mist to evaporate the water.
    3. The air is diverted out of the tower near the bottom, and it is filtered to remove fine particles, which can be recirculated back through the tower or reintroduced during the agglomeration step.
    4. Dry coffee powder collects in the bottom of the tower before being discharged for further processing. The resulting powder contains 2-4% moisture and consists of free-flowing, non-dusty particles.

There is one more method called agglomerate, and it is the same as the spray-dried coffee process with one difference.

  • Coffee oils or some other liquids are added to the spray-dried coffee while spinning in a tumbler, and that causes the formation of little instant powder granules as opposed to the powder looking like instant coffee.

There are a couple of considerations on which method to choose, related to the cost and the flavor retained. In a nutshell, spray drying is cheaper technology, and freeze-drying has the full flavor aroma of the coffee.

instant coffee steps

Spray drying process advantages and disadvantages4

The volume influences positively, and the solubility in water increases.

It is a relatively short and straightforward process.

Drying by spray drying is cheaper than freeze-drying.

A spray dryer has a much larger capacity than a freeze dryer.
Products are exposed to high temperatures; thereby, the product properties are damaged.

The product immediately takes a high temperature and gives its liquid to the warmer air.

Drying of liquids that almost can’t be heated through their properties without a considerable change of the product properties.

A spray dryer is constructed so that there are spots where lubricant can contact the product to be dried.

Due to the high temperatures, aroma, color, and taste of the powder can be affected.

Freeze-dried products advantages and disadvantages

The volume influences positively, and the solubility in the water increases.

After rehydration, the product has in strength level the properties of the original product.

The product has a short preparation time – The product properties stay intact because the drying process takes place at low temperatures.

The product is of high quality – The structure of the product stays intact; that’s why the product can absorb fluid again after the drying process.

The quality of freeze-dried products is the highest, mainly because the temperature stays low during the whole process.
The costs of the whole process are high, and the drying time is long.

The product can be 10 times more expensive than spray-dried products.

Freeze drying is an energy-consuming process.

It takes place at specialized expensive machines.

Freeze drying machines require a large investment.

The next steps in making instant coffee involve Aromatization and Packaging.

  • Aromatization – captured aromas that have been lost during the early steps of the manufacturing process are sprayed on the dry coffee particles. This may be done during the packaging operation.
  • Packaging – this needs to be done under low humidity conditions in a moisture-proof container to keep the product dry until purchased and opened by the consumer. Instant coffee is very susceptible to volatile oxidation and flavor release.
    • An increase in moisture content to 7%–8% is reported to be responsible for instant coffee “caking”, turning flowing powders or granules into a pastry or solid mass.
      Coffee needs to be packed in jars also with no more than 4% in-pack oxygen content and preferably less, so that the shelf-life to acceptable quality is maintained up to 18 months. If the moisture is less the then 5% w/w moisture content, it may last for a few years.5

Decaffeinated and Instant Coffees

Decaffeinated instant coffee was introduced by Nestle company in 1986.

In 1903, Ludwig Roselius, the head of the coffee company Kaffee HAG, discovered the secret to decaffeination by accident. A shipment of coffee had been swamped by seawater in transit – leaching out the caffeine but not the flavor.
He created a method to steam the beans with various acids before using the solvent benzene to remove the caffeine.
These days benzene is not used anymore, and there are a few different steps taken than in regular coffee production.

One crucial step in the decaffeinated process is starting when the coffee beans are still green.

According to Chris Stemman, the executive director of the British Coffee Association, “If you were to try and decaffeinate roasted coffee, you’d end up making something that tastes a bit like straw. That’s why with 99.9% of decaffeinated coffee to this day, the process is done at the green coffee stage.6

Methods to remove caffeine from coffee

There are different methods almost completely to remove caffeine. I’m using the word “almost” as there is still a small amount of caffeine left behind.

Solvent-Based ProcessNon-Solvent Process
Direct Solvent – The beans are first soaked in water and then covered in a solution containing either of these solvents. The solvent then draws out the caffeine.Swiss water – The beans are soaked with water; the caffeine-rich solution (full of flavors) is then strained through activated carbon which captures the caffeine.
Indirect Solvent – no direct contact with solventsCO2 – Beans soaked in water are placed in a stainless-steel extractor, which is then sealed, and liquid CO2 is blasted in at pressures of up to 1,000lbs per square inch.
Caffeine Extraction Methods
  • Methylene chloride is a clear, colorless liquid used not just for the decaf process, but also as an industrial solvent, paint stripper, and paint thinner.
  • Ethyl acetate, meanwhile, is a natural fruit ether usually made from acetic acid, which in turn may be produced from natural ingredients or petroleum derivatives.
  1. The Direct solvent-based process is done by soaking them in solvents either in methylene chloride or ethyl acetate. After that, the bans are heated to remove the caffeine-soaked solvents.
  2. Indirect solvent process – coffee beans are soaked in hot water for several hours, after they are removed, the water is treated with solvents, which adsorbs and removes the caffeine. After that, the beans are added back into the water.
  3. Non-Solvent Process – Similarity in both methods is that the C02 binds with the caffeine molecules, drawing them out of the non-roasted bean.

In the end, if we are chasing the all-elusive perfect cup of brew, we will never be satisfied with the final product. But if we look at the “chase” as a journey of discovering new flavors and experiences, we will have fun.

That also reminds me of people asking the bartender, “can you make me your best drink.” Well, I’m afraid there is no such thing. The best drink is what you feel while drinking at that particular moment.
The same principle can also be applied when you are going to your local store looking to buy the best coffee, and since no such thing exists, as everyone has different taste, I believe the questions we should ask ourselves are:

  • What do I feel like drinking today?
  • What flavors do I like to taste in my coffee?

Hopefully, having a little more information on what to look for in a coffee will help us narrow down the choices we make.


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