Arabica: What Really Defines the Species

Arabica is thought of as the fine coffee species. That is partly true – but two of the best-known claims about Arabica are now out of date: its share of the world market and the idea that Arabica is an original, pure species. It is a hybrid.

First things first: “Arabica” on the pack tells you which species is in the bag. It says little about quality and nothing at all about your taste.

What is Arabica?

Coffea arabica is the most widely cultivated coffee species in the world. Its natural populations are found in the mountain forests of south-western Ethiopia. From there it reached Yemen, where systematic cultivation began in the 15th and 16th centuries – and from there it spread to the rest of the world.

Botanically, it is a special case: the only coffee species with a fourfold chromosome set – all other Coffea species have a twofold one – and self-pollinating, whereas all other coffee species depend on cross-pollination. It is also the more demanding of the two cultivated species – it needs altitude, moderate temperatures and a short dry season that triggers flowering.

Why is Arabica genetically a special case?

Because it is not an original but a cross. Arabica arose from a natural hybridisation of the ancestors of Coffea canephora – that is, Canephora, also known as Robusta – and Coffea eugenioides. In the process, the chromosome sets were not halved; both were taken over in full.

Animation 1 · Arabica is a hybrid

Parent speciesArabica, the result

Each vertical line stands for one chromosome pair, i.e. two chromosomes. Both parent species have 11 pairs, which makes 22 chromosomes each – a double set, in technical terms diploid. Half of Arabica’s 22 pairs come from each of the two parent species. Arabica is the only coffee species with a fourfold set – all other Coffea species have a twofold one.

Sources: Salojärvi et al., Nature Genetics 56, 2024; Pinto-Maglio, Cytogenetics of coffee, Braz. J. Plant Physiol. 18, 2006.

This has practical consequences. Arabica carries two complete halves of genetic material, which means failures in one can be cushioned by the other – a buffer that has helped the species survive extremely narrow bottlenecks. At the same time, this very narrowness is its main problem, as you will see further down.

Self-pollination fits the picture: over 90 per cent of the flowers fertilise themselves. That makes varieties stable and reproducible – and explains why varieties such as Typica could be passed down as recognisable lines over centuries.

“Self-pollinating” does not mean “exclusively”. Bees carry pollen onwards, and cross-pollination can even increase yield. What is documented is over 90 per cent self-pollination, not 100.

When did Arabica emerge?

According to current research, the chromosome doubling dates back 350,000 to 610,000 years. This figure comes from the genome study by Salojärvi and colleagues, published in 2024 in Nature Genetics. Earlier estimates ranged from 10,000 years to a million – a span that is now considered outdated.

Animation 2 · Three dates that explain Arabica

EventSection shown by the next panel

Note: each panel has its own scale. The red-marked strip on the right edge of a panel is exactly what the next panel shows across its full width. The doubling lies roughly a thousand times further back than the start of cultivation – on a shared axis, you would not be able to see any of this.

Source: Salojärvi et al., Nature Genetics 56, 721–731, 2024.

More interesting than the age itself is a second finding from the same study: Arabica’s genetic diversity was already very low in the wild populations. Cultivation only reduced it slightly further. The common story that Arabica only became genetically impoverished through its colonial spread is therefore only half the truth.

How much caffeine does Arabica contain?

According to the scientific literature, green Arabica beans contain 0.7 to 1.7 grams of caffeine per 100 grams of dry matter, with typical values in a narrower range between 1.0 and 1.2 grams. For comparison: Canephora comes in at 1.4 to 3.3 grams, typically 1.7 to 2.1.

So the actual difference is a factor of about 1.4 to 2 – not 3, as is often claimed. There is more on this in the Canephora article.

Both ranges are literature values across many samples and growing regions with wide variation, not values for any particular bean – and we have not measured them ourselves. In any case, how much caffeine ends up in your cup depends on the dose.

Where does Arabica grow?

Higher up and cooler than Canephora. The optimal mean annual temperature is 18 to 21 degrees Celsius. Above 23 degrees, the fruit ripens faster, which regularly leads to a loss of quality; below 17 to 18 degrees, growth slows down considerably.

Animation 3 · Where Arabica grows

main cultivation rangefull documented rangeour own coffees (our own data)wild populations in Ethiopia

The further up, the higher the altitude. The solid bar is the main cultivation range, the dashed frame the full documented range. The two bars on the far right show two scientific sources on the wild populations that contradict each other – we show both.

Main range 1000–2000 m: Campuzano-Duque et al., Agronomy 2021. Lower limit 800 m (Colombia): PLOS ONE 9(12), e113510, 2014. Upper limit 2200 m: altitude of our Ethiopian coffees, our own data. Wild: left bar DaMatta et al. 2007, right bar Davis et al. 2012.

The cultivation altitudes and yields in this table are guideline values from the agronomic literature: ranges across many farms, varieties and years. The temperatures, too, are optimal ranges from trials, not limits. Someone else measured all this, not us.

Figures for rainfall differ in the scientific literature. One widely cited review gives 1200 to 1800 millimetres for both species, another 1500 to 2000 for Arabica and 2000 to 3000 for Canephora. That is why we don’t give a figure – the reliable difference between the species lies in temperature and altitude, not in rainfall.

How large is Arabica’s share of world production?

Smaller than you will read almost anywhere. The commonly cited figure is 60 to 70 per cent. The US Department of Agriculture’s production data from July 2026 paint a different picture.

The International Coffee Organization’s export figures point in the same direction: Arabica’s share of green coffee exports fell to 60.2 per cent in the first eight months of coffee year 2025/26, from 64.0 per cent in the same period of the previous year.

The percentages in the table are our own calculation from the absolute USDA volumes; the USDA itself does not publish shares. Also worth bearing in mind is Brazil’s biennial yield cycle, which makes the Arabica figures fluctuate from year to year. Even so, the trend is clear: Robusta is gaining ground. EstimateThe last row, 2026/27, is a USDA forecast: estimated, not harvested and not measured.

Why is Arabica so susceptible to disease?

Because little genetic diversity also means little choice of defence mechanisms. Coffee leaf rust, caused by the fungus Hemileia vastatrix, is the most economically significant disease in Arabica cultivation; yield losses of 35 to 50 per cent have been documented, and over 75 per cent in severe cases.

It is often said that Arabica has no rust resistance at all. That is not true. Several resistance genes – SH1, SH2, SH4 and SH5 in the literature – come from C. arabica itself. Others were added later: one from C. liberica, four from C. canephora via the so-called Timor Hybrid.

Global variety trials show this clearly: varieties with a pure Arabica background are on average more susceptible, while varieties with genetic material crossed in from other species are more resistant. That is exactly why old lines such as Typica are in retreat today.

Does Arabica automatically taste better?

No – but the chemistry explains how the reputation came about. On average, Arabica has more lipids (12 to 18 per cent versus 9 to 13), more trigonelline and lower levels of chlorogenic acids (5.5 to 8 per cent versus 7 to 10). Lower levels of chlorogenic acids tend to mean less bitterness and less astringency.

These are average values across the species, not statements about individual coffees. A carelessly processed Arabica from a low altitude tastes worse than a carefully processed Robusta from a good farm. The species sets the frame – cultivation, processing, roasting and brewing fill it in.

What does “100% Arabica” on the pack mean?

That no Canephora has been blended in. Nothing more. It says nothing about altitude, variety, crop year, processing, roast date or quality. A poor Arabica blend is just as entitled to call itself “100% Arabica” as an excellent coffee.

More useful are the details that actually make a claim: region, farm, altitude, variety, processing and a roast date. What that means in detail is explained in the article on Specialty Coffee.

Conversely, blending in Canephora is not a flaw. In Italian espresso blends, it is a tradition because it enhances body and crema formation. If you like that, don’t let a label put you off – and if you don’t, “100% Arabica” at least gives you something to go on.

How different can two Arabicas taste?

So different that the word on the pack is of little use as a buying guide. What makes the difference is origin, altitude, processing and roast – four things that make anything possible on a scale from light and fruity to dark and chocolatey. Three examples from our roastery, all of them “100% Arabica” and yet with hardly anything in common:

The first two come from the same farm at the same altitude – and still taste different. The third example is so far removed from them that people who love the one sometimes don’t even recognise the other as the same raw material. That is exactly why “Arabica” is a botanical label and not a promise of flavour.

If you want to find out where you stand, the quickest way is a pair: one light and one dark. You will find both among our coffee beans, and if you would rather be guided, come along to the workshops in Bern or Zurich.

Frequently asked questions about Arabica

What is Arabica coffee?

Coffea arabica is the most widely cultivated coffee species in the world. It originates from the mountain forests of south-western Ethiopia and is a natural hybrid of the ancestors of Coffea canephora and Coffea eugenioides. It is the only tetraploid species in commercial coffee cultivation.

Why does Arabica have 44 chromosomes?

Because when the two parent species crossed, the chromosome sets were not halved; both were taken over in full. Each parent species has 22 chromosomes, and Arabica carries all 44. The technical term for this is allotetraploidy.

When did Arabica emerge?

According to the 2024 genome study, the chromosome doubling took place 350,000 to 610,000 years ago. Earlier estimates ranged from 10,000 to a million years – this wide span is now considered outdated.

How much caffeine does Arabica contain?

According to the scientific literature, green Arabica beans contain 0.7 to 1.7 grams of caffeine per 100 grams of dry matter, typically 1.0 to 1.2 grams. Robusta is higher, but not three times higher – rather by a factor of about 1.4 to 2.

At what altitude does Arabica grow?

In cultivation mostly between 1000 and 2000 metres; the wild populations in Ethiopia grow between 1600 and 2800 metres. The optimal mean annual temperature is 18 to 21 degrees Celsius; above 23 degrees the fruit ripens faster, which harms quality.

How large is Arabica’s share of world production?

Considerably smaller than is usually claimed. According to USDA data from July 2026, Arabica accounted for around 53 per cent of world production in crop year 2025/26 and Robusta for 47 per cent. The commonly cited figure of 60 to 70 per cent is outdated.

Why is Arabica so susceptible to disease?

Because the species is genetically extremely narrow. It went through several bottlenecks, some of them even before domestication, and so has little variation from which resilience could develop. That is why coffee leaf rust hits Arabica harder than Canephora.

Does Arabica automatically taste better than Robusta?

No. On average, Arabica has more sugar and lipids and lower levels of chlorogenic acids, which favours a milder, sweeter impression. Even so, a poorly grown Arabica tastes worse than a carefully processed Robusta. The species is a starting point, not a verdict on quality.

Do all Arabicas taste the same?

No, and the difference is often greater than the one between Arabica and Robusta. Origin, altitude, processing and roast level determine the result. Two Arabicas from the same Ethiopian farm can taste of blackcurrant and of peach, whereas a Brazilian natural tastes of cocoa and dark chocolate. The label “100% Arabica” tells you nothing about any of this.

What now?

If you are curious how far “Arabica” goes as a category, try a little experiment of your own: two Arabicas from different countries side by side, prepared the same way. The difference between two Arabicas is usually bigger than anything the word on the pack promises.

Something concrete to explore: a light Bright Cassis against a dark Cozy Chocolate. From there, carry on with Canephora, Typica and Geisha. How to get it all into your cup is covered in the espresso dial-in and the V60 guide. Almost all of our coffee beans are Arabica – and the only way to find out which one you like is to taste them. We are United by Coffee.

Sources and context

• Details on our own roasts come from our product data; they are our own data.
• Genome, ploidy, parent species and dating of the doubling: Salojärvi et al., The genome and population genomics of allopolyploid Coffea arabica reveal the diversification history of modern coffee cultivars, Nature Genetics 56, 721–731, 2024.
• Caffeine content: dePaula & Farah, Caffeine Consumption through Coffee, Beverages 5(2), 37, 2019.
• Chemical composition of green Arabica and green Robusta: Socha et al., Foods 10(6), 1208, 2021.
• Temperature, rainfall and natural range: DaMatta, Ronchi, Maestri & Barros, Brazilian Journal of Plant Physiology 19(4), 485–510, 2007.
• Cultivation altitudes and yields: Campuzano-Duque et al., Agronomy 11(12), 2550, 2021; Campuzano-Duque & Blair, Agriculture 12(10), 1576, 2022.
• Production shares: USDA Foreign Agricultural Service, Coffee: World Markets and Trade, July 2026; export shares: International Coffee Organization, Coffee Market Report, June 2026. The percentage shares are our own calculations from the absolute volumes.
• Coffee leaf rust and resistance genes: Silva et al., Agronomy 12(2), 326, 2022; Berny Mier y Teran et al., Frontiers in Plant Science 16, 1583595, 2025.
• The scientific sources on rainfall contradict each other; this is pointed out in the text.