All coffee plants are separated into categories of genus and species. The Genus of all coffee is Coffea. There are several species of coffee, however Coffea Arabica is the genus and species of what the vast majority of specialty coffee is composed of. Coffea Arabica is also known as ‘Arabica Coffee’. There are hundreds of known and classified varieties of arabica coffee, as well as thousands that have not been identified as of yet..
Choosing which variety to grow has a lot of parameters for the grower themselves: disease resistance, yield of one plant, rainfall, fertilisation needed, etc. But when roasting, you may not even know that information or how a variety might play into your buying or roasting decision. Here, we aim to help inform you, to demystify the word ‘variety’ for you and how it relates to coffee.
First, an introduction to why variety might be important.
All coffee plants are descended from the first wild coffee plants that were used as medicine and food prior to the 1300’s. Cultivation of the wild plants began in Ethiopia around the 1300’s and plant genealogists pinpoint this period of time as when genetic divergence in Coffea began.
The first ‘different’ plants and their direct descendants are called ‘Typica Heirloom’. It is thought that these coffee plants were first cultivated as a crop in Yemen and were then taken to Bourbon Island (now called Réunion Island) in the 1300’s by French colonists. Coffee descended from the coffee from Bourbon Island are ‘Bourbon’ varieties.
The plants that were cultivated from Typica heirloom variety, that did not make the pitstop at Bourbon Island, are known under the branch of ‘Typica’ varieties.
Bourbon and Typica Varieties have mutated and been bred with other coffee plants over the past 700 years to create hundreds of unique varieties of arabica coffee grown all over the world. Yes, that’s a lot of unique varieties of arabica coffee, but according to a study by World Coffee Research, ‘The results of our genetic diversity study indicate that arabica have very little diversity—much less than was expected. This makes the species especially vulnerable to disease, climate change, and other threats. The most commonly grown coffee varieties are even more genetically narrow than the research collection.’
If we were to draw a family tree of Arabica coffee it would look a little something like this:
Each variety has its own expected amount that one plant can produce, unique bean size and density. Some varieties have unique flavour characteristics that you can expect no matter where they are grown, whereas other variety’s flavours may depend on the growing conditions of the plants. Each crop year is different and as coffee is an agricultural product, we cannot expect the same results from the same farm every year. There are ebbs and flows in rainfall, sunlight, and temperature, which will all affect the individual coffee plant’s outcome.
Variety names that you may find under this classification are ‘Sudan Rume’ and ‘Ethiopia Heirloom’. Within the variety classed as ‘Ethiopia Heirloom’ there are at least 6,000 known sub-varieties.These coffee plants most commonly resemble the plants that were growing wild in Ethiopia, 1 million years ago, until the 1300’s. That being said, because of the lack of genetic diversity within arabica coffee, these sub varieties are all classed as ‘Ethiopia Heirloom’, to simplify matters.
These varieties are most similar to the Geisha variety, in shape (thin and pointed), size and flavour characteristics. Typica tends to be very fragrant, complex, floral and sweet. Typica Plants are amongst the lowest yielding plants, susceptible to disease and generally have a higher cost due to the scarce amount that one tree can produce.
Mutations happen naturally in coffee. The mutations occur when a specific plant has been impacted by rainfall, sunlight and other factors in growing. The impact is so great that when an affected plant’s seed is taken to create a new plant, the new plant has physical characteristics that differ from the parent plant.
The most common Typica mutations that you may have come across are Blue Mountain and Maragogipe.
Blue Mountain: The mutation began in Jamaica’s Blue Mountains, hence the name, and is now widely grown in Hawaii and Papua New Guinea. It does not adapt well to different growing conditions and the plant grows quite tall. Blue Mountain variety tends to be very sweet, with a floral aroma, with flavours of nuts, cocoa, spices, and creamy mouthfeel. These coffees tend to be small and not very dense, meaning that they don't need very much applied heat to make them develop in the roaster.
- Maragogipe, pronounced "mar-ah-go-he-peh": also referred to as ‘Elephant Beans’, these coffee beans are huge. They tend to be not very dense, and the flavours depend largely on the soil type and the processing method. Like Blue Mountain, they tend to not need very much applied heat in order to develop in the roaster.
Yellow Catuaí, a Typica Hybrid of Caturra, a bourbon mutation and mundo novo in Brazil.
Typica Hybrids are the most common type of coffee varieties that you may have seen on a package of coffee. The hybrids are the product of breeding two different types of plants, typically a Bourbon mutation and a Typica mutation, together to solve a problem that a grower might face. These plants are bred to increase the amount of coffee that one plant can produce, become more disease and weather resistant, grow lower to the ground, etc.
The Typica hybrids that you may have had experience in tasting are Mundo Novo, Pacamara, Catuaí, and Marsellesa.
- Mundo Novo: the powerhouse of Brazilian specialty coffee. This is a hybrid of Bourbon and Typica Heirloom that is very high yielding, suitable to Brazil’s rolling hills landscape and distinct seasons. The beans tend to be more rounded than other varieties and the flavours tend to be quite mild; less sour and floral, more sweet and nutty. In roasting, it can take a darker roast and is well suited for espresso style roasting
- Pacamara: The hybrid most common in El Salvador, derived from a hybrid of Pacas, a bourbon mutation and Maragogipe, a Typica mutation. This variety is susceptible to disease and is low yielding, but it yields one of the most complex flavour profiles outside of Heirloom Typica. Pacamara beans tend to be quite large, due to its parent Maragogipe, which can make it difficult to roast evenly. The best approach is even, and gradual roasting, perhaps a longer roast to ensure that the coffee is roasted evenly.
- Catuaí: Though this Typica hybrid was first developed in Brazil in the 1950’s, it has spread throughout Central and South America. It is a hybrid of Mundo Novo, and Caturra, a Bourbon mutation. It is a popular choice for coffee farmers because of its high yield and weather resistance. Like Mundo Novo, the flavours are quite mild and sweet, but tend to have more of a drying aftertaste. Catuaí is well suited for espresso style roasting, as it tends to be quite sweet and chocolatey.
- Marsellesa: A new kid on the block, a hybrid of a Typica mutation, Sarchimor, and a Bourbon Mutation, Caturra. This plant tends to produce cherries that mature quicker than other Bourbon mutations, and are more weather and disease resistant than Typica, making it a good choice in windy and volatile growing conditions. Marsellesa coffee tends to have high quality sweetness and fruity flavours, with medium body. These coffees are very versatile in roasting and can shine bright in a light roast, or show their sweet side with more development.
Bourbon produces roughly 30% more coffee cherries than Typica plants do. They tend to have more of the chocolate, caramel sweetness than bright sweet and sour flavours of the Typica variety. Bourbon plants tend to be shorter and rounder, as well as more hardy than Typica plants, making them excellent to make hybrids with Typica plants.
Bourbon plants have larger leaves than Typica plants.
As previously stated, mutations happen naturally to all coffee plants. The most common mutations lend themselves to being the backbone of the specialty coffee industry.
- Caturra: If anything, this plant over-produces coffee cherries. The trees can become too heavy with fruit which causes strain on the trees. Caturra are dwarf plants which benefit from frequent hand picking to keep the strain off of the trees. Caturra can achieve a wide variety of flavours depending on the growing conditions and is a versatile coffee bean. It can take a wide variety of degrees of roast. It might be the best in a medium filter or espresso roast profile. The higher altitude this coffee is grown, the denser it will be, needing a higher roast temperature, the higher it is grown.
- Pacas: a similar variety to Caturra in its genealogy. However, it is wind and weather resistant which makes it a great variety to make a hybrid with. Pacas was first discovered in El Salvador on the Pacas family farm, and is now found widely through El Salvador and Honduras. Pacas has been hybridised with Maragogipe to create Pacamara (see in Typica Hybrids)
- SL28 & SL34: The two most common Bourbon varieties grown in Kenya. The SL stands for Scott Laboratories, a coffee research group based in Kenya from the 1930’s-1960’s. Scott Laboratories focused on breeding bourbon varieties brought from Yemen, which yielded varying results. They numbered their tests and numbers 28 and 34 had the highest yield and quality of all the tests. Both varieties tend to have a lot of ‘sparkle’, due to the high amounts of naturally occurring phosphoric acid, the acid often added to sparkling beverages to enhance the perception of carbonation. Due to the naturally sweet and sour flavours of these varieties, they are not especially well suited to darker or espresso profiles. They shine the most in the light to medium category of filter profiles.
- Mokka: One of the most unique varieties. Its origins point clearly to Yemen and if you have ever encountered Yemeni coffee, you have most likely seen the Mokka variety. Mokka beans are the smallest known arabica coffee beans, making them easy to spot. Mokka tends to have lots of cocoa and caramel notes, and sometimes can have more apple and pear notes. They rarely have bright sour and overly fruity flavours. These beans benefit from a longer, more gentle application of heat to make sure they are roasted evenly.
We could not end this without speaking about the most elusive variety of the bunch: Geisha.
Geisha, as far as any researcher or coffee scientist has proven, has a very close genealogy to Ethiopian Typica heirloom varieties. It is a rare variety that was ‘rediscovered’ in Panama by the Peterson Family in Boquete in the early 2000’s. The Peterson’s had separated a few areas of their farms into lots and kept those coffee cherries separate from others. They submitted the separated lots to the 2004 Best of Panama coffee competition. One of the specially separated coffees won the competition and went on to be sold for $350 per pound that year, a record breaking total. Since 2004, the Geisha variety has been propagated throughout the Boquete region and has been grown in Colombia and Costa Rica, with some success, though the highest price for Geisha is usually from Boquete; in 2019, one pound of unroasted Panama Geisha was sold at auction for $1029.
Geisha and its storied past deserves its own blog post, but we would be negligent to not mention Geisha here. When tasting a Geisha you can expect lots of complexity. The taste is almost unlike coffee as you may know it: intensely floral, juicy, with tropical and citrus flavours, overwhelming sweetness, and a thin tea-like mouthfeel. Roasting this coffee is a rare occasion: most commercial specialty coffee roasters never have the experience themselves. Roasting Geisha requires a light roast to amplify the bright and intense flavours, naturally occurring in the coffee.
We hope that this was helpful to you and that you can use this article as a resource when next choosing the green coffee you would like to roast. As always, we welcome your feedback and suggestions for green coffee you would like us to carry at firstname.lastname@example.org
Sources/ further reading:
Dear Coffee Buyer: A guide to sourcing green coffee by Ryan Brown
The World Atlas of Coffee by James Hoffman