How Coffee is Made

Ethiopians reportedly first used the Kaffa plant to make coffee during the 15th century. Most of the beans they used came from the Yemen province until the 17th century.

Between the 16th and 17th centuries, the use of coffee spread through most of Europe. Indonesian islands began to use it during this time too. North America didn’t have coffee in Hawaii until 1825 though.

The South American country of Brazil became one of the largest producers of coffee by the 20th century. During this time manufacturers had developed grinders, roasting machines, vacuum storage seals and decaffeination methods. Instant coffee came on the scene in the 1950s.

By the way, you might come across legends of coffee origins that tell a different story. Some of these accounts suggest the presence of this beverage offered as early as 850 AD (BCE). Apparently, Kaldi had a goat “act up” and allegedly not sleeping well after eating a bean from a tree known later as coffee.

Four Popular Coffee Plant Beans

Arabica beans makes up 60-70% of all the coffee made worldwide. However, there are at least 25–possibly up to 100–other species of beans. Some of these include Robusta, Liberica and Excelsa.

Arabica

Coffea Arabica, otherwise known as Arabica coffee, comes from a flat bean longer than the Robusta. Arabica subtypes include Tico, San Ramon, Bourbon, Typical and Jamaica Blue Mountain, and more. This coffee grows 2,000-6,000 feet in elevation.

Growing Arabica coffee calls for temperatures between 59-75 degrees F. Rainforests that receive at least 60 inches of rain throughout the year would be ideal. Growers have to pay attention to possible diseases, and this bean requires more care than the Robusta type.

Robusta

You will find Robusta predominately in Central and Western Africa. Indonesia, Vietnam and Brazil also have it. This bean only makes up 30% of what’s sold around the world, but it does serve well for use in blends and instant coffees.

Unlike the Arabica, the Robusta has a round rather than flat shape. It also resists diseases easier than the Arabica bean, and it grows between 75-85 degrees F. Robusta needs about 60 inches of rainfall per year and contains about 50% more caffeine than Arabica.

Liberica

Coffea Liberica (Liberica Coffee) shows up in much smaller quantities than the varieties of Arabica and Robusta on the market. It only makes up about 1.5% or less of what you can find on the market. It has an oval shape and is longer than the Excelsa bean.

Liberica has a slightly bitter taste different from Arabica or Robusta, and it reminds some consumers of the Southeast Asian jackfruit. It originates from the Philippines, where it first became commercial in the 1740s.

Liberica grows best in about 69-70 degrees F temperatures. Ideal elevation for producing this crop is about 6561 feet (2000 meters) above sea level. It requires plenty of rainfall, probably at least 50-60 inches per year.

Excelsa

Excelsa is a subtype of Liberica coffee, and its bean is rounder than Liberica. It has a strong, acidic taste and may have less caffeine in it that some other beans. It originates from Africa, Asia and South America.

Excelsa doesn’t seem to need as much water as other bean types. It does, however, do better in elevations at least 3000 feet above sea level.

Harvesting Coffee Cherries

Before you even see a coffee bean, it has to be harvested from the coffee cherry. This grape-sized fruit typically turns red, then purple or yellowish-red as it reaches maturity.

The pit inside a coffee cherry is where you would find the coffee bean. The coffee cherry does have some nutritional value. However, coffee manufacturers typically discard the fruit and keep the bean when making coffee.

Hand-picking vs. Machine Picking

Hand-picking can become time-consuming, so it’s only done when wanting to produce specialty coffees. On the other hand, hand-picking coffee beans does make the sorting process easier. In this case, harvesters only choose the best ones.

Machine picking takes less work during the harvesting process. However, you have to spend time sorting out the ones not ripe enough, damaged, etc. Either a small handheld device or a larger, farm-sized stripping equipment is used in machine picking.

Harvesting Season by Region

In Central America, such as in El Salvador, Guatemala or Panama, harvesting usually takes place from October to March. In the Dominican Republic and Cuba, it usually occurs from September to March.

South American coffee harvests usually occur from April to October. Some major producers include Peru, Bolivia, Ecuador and Brazil. Columbia is another one. Each one of these locations may have alternate times when they do produce beans for popular beverages.

In Africa, the primary harvesting time takes place from October to April. However, coffee in Burundi and Rwanda is harvested from April to September.

A fly crop also comes from Kenya between June and August. Moreover, coffee may come from Tanzania as early as September to as late as January of the following year.

In Asian countries, such as India, the harvest may happen from October to February. Indonesia may have it from June to December, depending on if its Robusta or Arabica. In Papua New Guinea, you probably will find coffee fruit between May and September.

How to Select Ripe Cherries

The ideal bean taste is achieved from picking ripe coffee cherries. However, you don’t want to use overripe cherries, which may develop diseases more readily than less-ripe ones.

Ripe cherries will feel soft when you squeeze them. Depending on the variety, they will also have a glossy bright red appearance. Others may appear bright yellow or orange. If hand-picking, wait until your coffee fruit turns one of those colors.

Hand-picking coffee cherries may take you more time than you want to invest, however. If so, wait until at least most of the cherries appear ripe and use a strip harvesting machine.

Processing the Coffee Cherries

Dry (Natural) Method

The dry method, otherwise known as the natural method, starts without washing the coffee cherries. They’re often dried on raised beds, in a sun patio area, or in mechanical dryers.

To ensure the most efficient drying, the coffee cherries are laid out in thin rows. This setup also prevents molding, rotting and fermentation. The drying method also involves rotating the product frequently to allow for necessary airflow, which also prevents disease formation.

After drying, that’s when the fruit of the coffee cherry is removed. This happens either by hand or using a machine. The dry coffee method sometimes gives it a red-wine hint if any fermentation has occurred, but it’s usually a fruity tone.

The Wet (Washed) Method

For the wet method, processors use water to wash away the coffee cherry’s skin and pulp. Then, they place all the beans into large tubs of water, which separates the beans that float to the top from the beans that sink. This is how defective beans are detected and removed.

After this, the coffee beans are placed into a fermentation process. This is the only way to remove the mucilage that you can’t just dissolve in water. After this, sun drying or mechanical drying and roasting takes place.

During the fermentation process, the beans taste like wine. However, the finished product after processing turns up a clean, consistent flavor.

Honey and Pulp Natural Processing

During the honey and pulp natural process, a de-pulping machine removes the coffee cherry skin. Some of the sticky substance called mucilage also is removed, but some of the mucilage remains.

A pulped material resembling honey is the end result of this pulp natural processing technique. Sometimes, a greater amount of mucilage left on the beans produces a darker substance. For instance, you could end up with what is nicknamed “red, gold or black honey.”

The darker natural-honey-processing bean substance provides a sweeter coffee taste. It sometimes makes an excellent cold brew for people who like its mild tone.

Preservation of Flavor During Decaffeination

Some people love the taste of coffee but prefer it without caffeine. Preserving flavor during the decaffeination process happens using one of four major processes:

Direct-Solvent

This involves direct placement of either the ethyl acetate or methylene chloride chemical in contact with coffee beans. During this process, the beans are steamed for about 30 minutes, which opens up their pores.

The opening of pores releases the caffeine. Then, the beans go through a 10-hour, repeated rinsing process.

Indirect-Solvent

The indirect-solved method soaks beans in hot water. This absorbs the caffeine. Then, processors will transfer the beans to another vat of hot water with chemicals.

The chemicals (solvent) rises to the surface with the caffeine. After skimming the solvent-caffeine mixture, the flavored coffee water from the first tank is mixed with the second.

The beans soak up the coffee-water mixture. That’s how all the beans' flavors, proteins and other components are retained minus the caffeine.

Swiss Water

A similar steaming and soaking technique is used as is for the indirect-solvent method. However, an activated charcoal filter is used for collecting the caffeine molecules. This happens while retaining the bean’s flavors and oils. After this, the beans are slowly dried.

Carbon Dioxide

Using this method involves applying carbon dioxide pressure at about 1,000 pounds per square inch. This CO2 is injected in liquid form into a sealed metal container, which becomes the extraction basin.

The dissolving CO2 carries the caffeine with it and leaves behind the bean’s flavors. The CO2 then gets captured into an absorption chamber to be used again.

Milling the Coffee Beans

First, processors inspect the coffee beans for impurities, and any existing stones or debris are removed. After that, the hulling process begins.

“Hulling” refers to the removal of the dried bean husk. This happens after the coffee cherry pulp has been either washed and/or dried. A hulling machine usually makes this process easier, using air and friction to remove the husk.

Once the husk is removed, coffee producers may polish the green bean that is left. During the polishing process, any presence of silver skin is removed.

Rotary or vibrating polishing machines speed up this process. However, it’s also possible to use sandpaper to smooth each bean.

How Coffee Beans are Graded and Sorted

Producers put careful thought into how coffee beans are graded and sorted. This helps set pricing points for different coffee quality ratings. It also provides a standard for identifying and removing defective beans.

Coffee bean sizes are graded according to diameter sizes from about 8 to 20 in 64th of an inch. For instance, the grade 13 would be 13/64 inch in diameter.

These coffee beans are also sorted using screens with holes in it of different sizes. During this process, the beans in the screens also can be sorted by weight.

The coffee grading scale is typically one through five, with one being the highest quality. Grade One coffee usually has no more primary defects but a maximum of three full defects. It can’t be more than 5% above or below the screen size used to measure it.

Grade Two beans have almost as high of quality as Grade One but allow for a total of eight defects. This premium level of coffee is what a majority of people may want to drink.

Grade three coffee probably appeals to people looking for caffeine stimulation when money is tight. It may have between nine and 23 defects, and it may measure 50% above its Exchange Grade screen size and no more than 5% below it.

Grade four probably would be the limit of defectiveness on coffee that you want. It might have 24-300 full defects per 300 grams of quantity. The Grade Five surpasses this in defects and renders useless for the most part.

Taste testing each grade also is important. Five elements to consider when evaluating coffee include aroma, flavor, acidity, body and aftertaste.

One way to taste-test coffee is to allow it to run over your tongue and hold it a minute or two. Another is to take a spoonful and apply a good suction action as you slurp it into your mouth.

Roasting the Beans

The World Coffee Research Sensory Lexicon identifies more than 100 flavor profiles. Some of these include the sweet, bitter, nutty or fruity. Others may have a fermented taste.

The different flavor profiles represent light, medium or dark roast varieties. The lighter roasts may have a mild taste, perhaps a nutty appeal. Medium roasts typically come out sweeter than the light roasts, and the dark roasts have a distinct acidic, burnt or caramelized sensation.

The lighter roasts often have a more pleasant aroma, depending on your preference. However, some people don’t mind the “black coal” taste, smell and appearance of darker coffee.

Grinding the Beans

There’s a huge difference between the coarsely ground coffee you would put in a French press versus the medium grind you put in a drip brewing machine. The espresso, which is one of the finest grinds of coffee you can find, requires a pressurized brew.

Storing the Beans

To preserve your coffee beans, store them in an airtight container. Some experts recommend glass instead of plastic to avoid material flavor transfer into your coffee. You also can place beans or grinds in the freezer.

Brewing the Coffee

It depends on the grind size and the type of brewing machine you have. However, you can achieve the best taste and reap the highest level of caffeine benefits at about 195-205 degrees F.

The ideal coffee temperature recommended by us applies to any brewing method. For instance, you can use the automatic drip brewer or the pour-over drip equipment to filter your beans.

Espresso making may require temperatures of at least 197 degrees F, however. That ensures the best chance of coffee extraction for achieving the flavor and stimulation you desire.

Summary

This introduction of how coffee is made will help you understand the reason why so many varieties exist. Producing coffee from its initial harvest is not as simple as your average vegetable gardening.