The journey of coffee’s aroma is a sensory adventure that spans continents and cultures, from the fertile soils of the plantations to the kitchens and homes of the world. Discover the aromatic journey of coffee: bean to brew, and the different types of preparation.
In this Article
Nurturing the beans
Each demitasse we savor is a testament to the artistry of nature and the expertise of those who cultivate and harvest the beans, quality coffee has its origins in the heart of the coffee plantations. Coffee farmers meticulously nurture the plants, ensuring proper soil fertility, preventing diseases, and managing shade and sunlight exposure.
Arabica and Robusta coffee beans
The two main species of coffee have different botanical and chemical features and qualities. These dictate where they will naturally thrive and offer a sustainable crop, as well as how the coffee beans will be categorized and priced. These features also indicate a particular favor profile.
Beans from an Arabica plant have a mild flavor, slightly sweet, with a hint of fruit or berry taste. Coffee beans from the Robusta coffee plant have a higher level of caffeine and a more harsh flavor.
Arabica
Coffea arabica – the popular Arabica bean originally comes from Ethiopia. A coffee species grown mainly in South and Central America, South India, Sumatra and East Africa. Its share of world production stands at around 70%.
Arabica plants grow best at higher altitudes between 800 and 2,200 meters above sea level. They need regular water and are sensitive to drought, persistent rainfall, wind and cold. On the palate Arabica coffee impresses with its fine and fruity notes and is also light and extremely nuanced in terms of flavor.
Robusta
Coffea canephora – as the name indicates, the Robusta plant is robust: durable and resistant than the Arabica plant. Pests and temperature fluctuations have barely any impact on it.
In comparison to the Arabica bean, the Robusta bean grows more quickly and flourishes at lower elevations of up to 800 meters above sea level. Its home is West Africa and the tropical areas of Asia; its flavor is earthy, rugged and slightly bitter. More and more coffee producers in Asia are looking to develop higher quality Robusta beans.
Selecting the coffee cherries
The fruit of the coffee plant, undergo careful harvesting to ensure the highest quality beans. There are two primary methods: selective picking (handpicking only the ripe cherries) and strip picking (harvesting all the cherries from a branch at once).
The morphology of the coffee cherry
The layers of the Coffee cherry starting from the outside, are:
Outer skin / Pulp: On the outside, the two coffee seeds are covered by a cherry-like skin and pulp. With the exception of dried-in-the-fruit or Natural Process coffee, this outer layer is removed within a few hours of harvesting. In a cherry, like a plump this skin is the “flesh.”
In coffee, the skin is mostly considered a by-product, however some people make tea or marmalade out of it. The machine to remove the pulp is aptly called a depulper.
Pectine layer / Mucilage: Beyond the skin lies the mucilage, a sticky, gluey substance surrounding each of the two seeds. Because it’s so sticky and sugary, it is sometimes called Honey. Mucilage is found in most fruit, it’s not unique to coffee.
Parchment: After the mucilage, a layer of cellulose protects each of the coffee seeds. When dried, this layer looks and feels like parchment paper, hence the name.
Silver skin / Chaff: Further inside, an even thinner layer coats the seed. This layer is called the silver skin because of its somewhat silverish sheen.
This layer comes off during roasting. If you ever notice flakes in ground coffee, that is usually bits of silver skin or chaff that didn’t separate from the beans during the roast process.
Seed / Coffee Bean: The coffee bean is one of the two seeds from inside the coffee cherry.
Sidenote: peaberries are an anomaly in which only one small, round seed formed inside the cherry. Usually, about five percent of all coffee is graded as a peaberry.
The flavors of the green bean
Separating the coffee beans from the fruit:
Natural Process: In this method, the cherries are dried with their fruit intact. The sun’s heat and airflow transform the cherries into dried, raisin-like fruits. Natural processing brings out fruity and wine-like flavors, along with a full body.
Honey Process: This process lies between the washed and natural methods. The cherries are partially washed, leaving some of the fruit pulp intact during the drying process. It leads to beans with a unique sweetness and complexity.
Types of honey processed coffee
There are three degrees of honey processing depending on how much mucilage is left on the beans before drying.
- White Honey implies removal of 80-100% of mucilage with mechanical equipment and then sun drying for 8 – 10 days.
- Yellow Honey implies removal of a good portion (50-75%) of mucilage with mechanical equipment and then sun drying for 8 – 10 days.
- Red Honey, where producers only remove 25-50% of the mucilage and then they sundry the beans for 12-15 days
- Black Honey, where the beans are dried with little or no mucilage for up to 30 days.
Washed Process: This method involves removing the outer skin and pulp from the cherries using water and fermentation. It results in clean, bright beans with a vibrant acidity.
Processing has a great impact on bean and cup quality. Here are the most relevant flavor notes you can expect from the different processed coffee beans.
Naturals
- Heavy body
- Fruity taste
- Sweet, smooth and complex attributes
Washed
- Pronounced acidity
- Pronounced aroma
- Less Astringency
Honey Processed
- No unwanted harsh notes of green or unripe cherries of Naturals attributes
Roasting Magic
The roasting process is where the beans develop their distinct flavors and aromas. As the beans dance in the roaster, their scent evolves from grassy to toasty, with hints of nuttiness and spice. The aromas of caramelization and bitter sweetness fill the air, announcing the beans’ transition from raw to fragrant. It’s in this process that the character of coffee emerges.
The roasting process can be monitored by ear, by listening for events known collectively as “first crack” and “second crack”, which also signify the progression of the roast.
The degree of roasting is crucial: Lighter roasts tend to smell fruitier, and more floral and herbaceous. Meanwhile, medium beans give off more of a caramelized, nutty, or even chocolatey smell. Dark roasts tend to be earthier, bolder and sometimes they are even smoky.
Grinding the coffee beans:
On the picture, a detail view of a coffee burr grinder. The bean hopper, which would be immediately above this grinder, has been removed.
Transforming coffee beans into a fragrant powder is a pivotal moment that sets the stage for the aromatic symphony.
The release of essential oils from the freshly ground beans fills the air with a potent and irresistible aroma.
Grinding coffee increases its aroma by increasing the surface area of the coffee to release more aromatic compounds.
Coffee beans shall be freshly ground: after only 15 minutes from grinding the product loses 65% of its aromatic profile.
Brewing Rituals:
Each step of the brewing process releases a symphony of aromas, captivating our senses and building anticipation for that first invigorating sip.
Brewing coffee produces even more aroma, as the hot water extracts different chemicals. That’s why a cup of coffee may not smell the same as the ground coffee produced.
As hot water or steam meets the ground coffee, a dance of aromas ensues, the coffee flavors can range from floral, fruity, savory to sweet. Chocolaty, berry like or herbal can describe the papillary sensations of a great cup of coffee.
Coffee brewing methods:
The brewing process, whether it’s through decoction methods – boiling (boiled coffee, Turkish/Arabic coffee, percolator coffee, and siphon, or vacuum coffee), infusion methods – steeping like gravity brewing methods – percolators & in drip brewing (drip filter coffee, french press, Turkish/ Arabic coffee, Indian filter Kaaapi, Moka, and Napoletana), and the pressure methods (Moka and espresso), infuses the air with an aroma that tantalizingly teases the senses.
Extraction
The process of extracting the substances contained in the coffee beans (fats, acids, amino acids, sugars, Co2).
Decoction method
The coffee grounds will be placed inside a vessel or a cup, and then near-boiling or boiling water will be poured on them. ‘Cow boy coffee’ is made by boiling ground coffee directly in water. The grounds will sit in the hot water until it is cool enough to drink.
Turkish/ Arabic coffee or Ibrik Method
The Ibrik method takes its name from the small pot that is used to both brew and serve coffee in the 16th century Ottoman coffeehouses and Arabic and Turkish homes. This method still stands today.
In this small metal pot coffee grounds, water, spices and sugar are mixed. This is then bought to almost boiling point, before being cooled and heated repeatedly a few more times. It will then be poured into a cup to be drunk.
Enjoy it slowly as to avoid the grounds that settle on the ground of the coffee cup.
Infusion methods
Pour over
Coffee brewed by pouring water over a bed of ground coffee contained in a filter.
Filter coffee
The filter or filter coffee is prepared by steeping coffee ground in boiling water.
Socks and cloth filters
Legend has it, that the method of filtering coffee may have been developed by pouring hot water through a sock filled with ground coffee.
This revolutionized coffee-making, cloth was now used to filter the grounds.
This method is still used in South America, the Caribean, India, Malaysia and Indonesia.
Paper Filters
Coffee brewing was further revolutionized in 1908 when the first paper coffee filter was created.
Melitta Bentz was fed up with having to constantly clean out the coffee from her pot, and decided to use a piece of paper to line the pot instead.
V60
Extraction method that gets its name from the 60-degree angle created by the cone’s shape. This pour over method brews a coffee with a light-bodied and distinctive taste, similar to an infusion with a rich aroma. The water is poured at 96 degrees.
Chemex
This pour over extraction method works with a manual filter. This brewing method is said to create a sweeter coffee. The filter is thicker than that of the V60, and therefore do a better job of putting out oils, leaving a cleaner cup.
Drip coffee
Drip brewing methods evolved in the early 19th century. This method of brewing sees hot water dripped into a filter filled with coffee grounds. The water passes through the filter into the coffee pot below and is kept warm by a heating pad. This method is particularly popular in America today.
Cold drip coffee
Coffee grounds are steeped in cold water for a very long time (at least 7/8 hours). The technique requires a ‘drip tower’ that consists of three glass vessels: a glass top where cold water is poured, a central container for coffee grounds and a carafe on the bottom to collect the final product. The coffee is passed through the water one drop at a time, for a percolation of about 8 drops every 10 seconds.
Drip coffee pots don’t use paper filters but a permanent filter featuring many small, round, drilled holes made out of (enameled) metal, ceramics or porcelain.
Metal Filters
Metal filters were first introduced in France in the early 1800s. This was developed into an early version of the French Press, with a metal filter combined with a rammer to compress the coffee grounds.
French Press
Its was first patented in 1852 in France; since then, the design has changed a few times. In fact, the type of French Press we know today was actually created by a Swiss-Italian, although it was produced in France.
The French Press works by soaking coarse coffee grounds with hot water and then using a metal plunger (a wire mesh filter) to separate the two. You can then pour out the brewed coffee, leaving the used grounds behind.
Neapolitan flip coffee pot
The cucuma coffee maker consisting of a bottom section with the boiler filled with water, of a filter section with ground coffee, and of an upper section with the spout and the lid.
When the pot begins to steam, it must be turned upside down, letting the water percolate through the filter.
The coffee that is obtained with the Neapolitan cuccumella is as intense as an Italian espresso with a lot of body. The difference is in the aroma, which is more delicate due to the fact that the extraction of the coffee is more delicate.
It is : ‘O caffè perfetto, the perfect coffee’ for South Italians and Neapolitans.
Vacuum coffee maker
It brews coffee using two chambers containing water and coffee ground, connected by a narrow siphon tube. Steam forces the water to rise into the upper chamber where the coffee grounds are placed. The pressure eases up and lets the now-brewed coffee through the strainer.
Percolators
Following the development of the metal filter, percolators were then developed and made popular during the 1800s. The percolator uses steam pressure to brew the coffee; at the top of the pot is a metal filter filled with coffee grounds, and as the water boils, it rises over the coffee grounds and then seeps back through the filter leaving brewed coffee.
Siphon Pots
A siphon pot, also known as a vacuum brewer, was also created in the early 19th century. These pots resemble an hourglass, with heat at the bottom building pressure and forcing water to siphon and mix with ground coffee.
People liked this method, as the glass allowed them to see the coffee as it was brewing. However, it did present some risk at the time, as getting the pressure wrong could cause the glass to explode! Despite this, the siphon pot became commercially available in the 1840s and has retained its charm with artisan coffee makers to this day.
Infusion, steeping, immersion Method
Coffee grounds will be left to steep in the water for a few minutes or for several times. A filter/plunger is used to contain the grounds and the brew is separated from the grounds.
Biggin Pots
These pots, created in 1780, featured a place for the cloth to sit in the coffee pot, allowing to pour the coffee out through the filter. However, these presented a number of issues.
For one, many coffee lovers found that their brew was being tainted by the taste of whatever bit of cloth was being used. Secondly, if the coarseness of the coffee grounds was wrong, problems arose. For example, if the grounds were too coarse, the water would pass through too fast and create a very weak cup of coffee.
De Belloy coffeemaker
From the earlier coffee biggins (1780) where cloth filters would be used, drip coffee pots with a permanent filter featuring many small, round, drilled holes made out of (enameled) metal, ceramics or porcelain emerged.
Today’s South Indian drip brew coffeemaker are based on the “French drip” coffeemaker attributed to Archbishop De Belloy.
The inventor of the South Indian coffee filter is lost to history – as Doctor mentions here, the one in use today might well be a homegrown, practical, metal version of the foreign percolators introduced to India.
Most households have a stainless-steel coffee filter, passed down within families, and shops sell freshly roasted and ground coffee beans. The stainless steel or brass percolator is divided into two halves, with a plunger, and an airtight lid. The bottom of the upper half is pierced with small holes, through which the coffee drips into the container below.
Nitro Coffee
Nitro coffee is a type of cold brew coffee that is infused with nitrogen gas to give it a creamy, smooth texture. Many people enjoy the creamy, velvety texture and smooth flavor of nitro coffee, which is often served straight from the tap like a draft beer.
Pressure method
Espresso is made by forcing hot water at 91–95 °C (195–204 °F) under a pressure of between eight and eighteen bars (800–1800 kPa, 116–261 psi), through a lightly packed matrix, called a “puck,” of finely ground coffee.
Moka pot
An espresso-like coffee is brewed in the Italian Moka pot. The standard pressure of modern espresso machines is at least 9 bars, the Moka uses a pressure of about 1.5 bars.
Coffee maker designed by Alfonso Bialetti and composed of 4 aluminum or steel elements: the boiler, filled with water, the metal filter, the upper chamber, equipped with an additional filter, and the safety valve that works as pressure regulator.
The lower section of the moka, is where water is boiled and then forced up by the steam pressure to go through the coffee grounds in the midsection chamber. The coffee will then be collected inside the high chamber, where it will condense.
Espresso Machine
Experiments with steam pressure brewing have been undertaken in Britain and France as far back as the early 1800s. The removable portafilter espresso coffee machine was developed in 1901 by Luigi Bezzera an imposing, gorgeous, complicated affair with assorted spigots, handles, and gauges, some topped with a resplendent eagle.
The modern Espresso era started, when Achille Gaggia (1895–1961), developed first the “a torchio” system in 1936, and renamed it “Lampo” in 1938. This disruptive mechanism used hot water pressure instead of steam and prepared a delicious espresso, characterized by a soft layer of “crema naturale”. A true and delicious innovation!
Since, the espresso machine has seen many remodels and upgrades. Italian espresso, cappuccino delicacy and bar culture are based around the espresso machine and espresso culture.
Espresso capsules are rigid plastic or aluminum coffee container to use with espresso machines.
Aeropress
The AeroPress was invented by Alan Adler in 2005. The extraction method combines pressure and immersion. AeroPress coffee is rich and smooth due to the pressure under which the coffee is brewed.
Instant Coffee
While some coffee lovers will avoid it, instant coffee is undoubtedly one of the easiest ways of brewing coffee, as only hot water is required. Instant coffee solids (also called soluble coffee, coffee crystals, coffee powder, or powdered coffee) refers to dehydrated and packaged coffee solids.
It starts with green coffee beans that are roasted and then finely ground. Then the beans are hit with piping hot, highly pressurized water. This brews the coffee grinds and extracts the oils and compounds into the water.
This brewing process is followed by an evaporation phase, finally, the concentrated brew is freeze-dried, before being broken into small pieces or powder. Instant coffee was slightly improved during the 1960s when dry freezing was used to better preserve the rich flavor of coffee.
Historians believe that the predecessor to modern day instant coffee was independently created by three people in three different countries between the years 1880 -1901; a Frenchman by the name of Alphonse Allais, a New Zealander by the name David Strang and an American/Japanese by the name of Satori Kato.
The variety of brewing techniques for coffee, that have been developed and used traditionally in different countries is indeed extraordinary.
Whether you’re a casual coffee drinker or a seasoned coffee connoisseur, the magic of coffee offers a moment of joy that can be savored each and every day, or several times a day.
Coffee is essentially a matter of personal taste and heritage – it’s your cup of coffee – enjoy it.
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