The Many Types of Coffee Beans


I was doing some research for an article about potential coffee extinction when I came across a few species of coffee that were new to me. And I wondered how many Coffea species there actually were. I started digging and boy was I surprised at the answer!

Although the vast majority of the world’s commercial coffee production is either Arabica (Coffea arabica), which accounts for almost 70% or Robusta (Coffea Canephora), which accounts for almost 30%, there are actually 124 coffee species known to science, many of which are found only in the wild.

It’s All Just Coffee

That’s right… as of May 2019, there are 124 separate known coffea species! Coffee grows only on Earth (as far as we know) and almost exclusively in the tropics. The “coffee belt” is generally considered to lie between 25º north latitude and 30º south latitude and coffee is now grown in at least 90 countries. The naturally occurring (wild) coffee strains are mostly found in tropical Africa, the Islands of the Indian Ocean, Asia, and Australasia.

map of the bean belt
World map of the Bean Belt; the only places coffee grows (more or less).

Although there are 124 species, the coffee bean morphology (shape and structure) is largely the same.

Now, coffee is not actually a bean… I went into this topic at some length in a previous post. A coffee bean is actually the seed of the coffee fruit (it’s not actually a fruit, either… it’s a “drupe,” but let’s not get too carried away)

The fruit grows on a coffee tree (which is actually not a tree: it’s technically a shrub… I know. I’m being pedantic, but isn’t that why we are all here?). The fruit is made up of the skin, a thin layer of pulp, a seed coat, and a seed that is generally in two halves, although sometimes it is a single caracol or “peaberry.” As I said, across the species, this is what you will find. But there are differences.

Vive La Difference

Although there are many similarities, there are differences between the species. Sometimes the differences are subtle, as in leaf structure or leaf distribution. Sometimes the differences are easy to spot: Some species produce more than others and the color of the fruit can vary from yellow to orange to red to dark purple. The size of the fruit and seed can vary from 5 mm of the Coffea racemose to the 20 mm of the C. ambongenis. There is even a variety, C. namorokensis, that produces a hairy fruit.

Useful Traits

The genetic diversity of the wild species of coffee are important because some of them have desirable characteristics that might be useful as growing conditions change due to climate shifts. A drought resistant species might just come in handy. In the late 1800s, almost all the Arabica trees in Java were wiped out by coffee rust, but the hardy Robusta tree has come a long way toward rebuilding the coffee industries of Indonesia.<LINK> Other varieties have other pest and disease resistance.

It is probably not surprising that the caffeine content can vary from species to species. In fact, C. racemose has a caffeine content so low that it is naturally as low as decaffeinated coffee!

The big thing for me is taste. It is for most other people, as well. Arabica has been the king of that particular mountain for many years, but researchers are always looking for ways to produce a better cup. Besides, as we learned earlier, Arabica is susceptible to coffee rust and we don’t want to face a world without good coffee.

Arabica

The first cultivated species of coffee tree and the most widely grown due to its superior flavor and good production. Approximately 70% of the world’s coffee production, and all the best tasting coffees, are Arabica (C. arabica). There are dozens of varieties and cultivars of Arabica.

Robusta

About 27% of the world’s coffee is Robusta (C. canephora). It is a lower-growing, higher-bearing tree and produces coffee that has higher caffeine content and inferior cupping quality to Arabica. Because it is lower growing, on flatter land, it is more suitable for mechanical cultivation, allowing for economies of scale making it less expensive to produce. It is used in blends of instant coffee, and for less expensive blends of ground commercial coffee. Some blenders claim that combining it with Arabica beans gives more body to a cup of espresso.

Other Notable Coffees

Eugenioides coffee (C. eugenioides) is indigenous to the highlands of East Africa, including the Democratic Republic of Congo, Rwanda, Uganda, Kenya and western Tanzania. It has a lower caffeine content than Arabica.

Liberica (C. Liberica) grows much taller and has larger fruits than Arabica, although the per tree yield is lower. The coffee “beans” are often irregular in shape. Liberica trees were brought to Indonesia to replace the Arabica trees killed by coffee rust. Excelsa is a popular varietal of Liberica.

A Complete Alphabetical List of
All Coffee Species

  1. Coffea abbayesii
  2. Coffea affinis
  3. Coffea alleizettii
  4. Coffea ambanjensis
  5. Coffea ambongenis
  6. Coffea andrambovatensis
  7. Coffea ankaranensis
  8. Coffea anthonyi
  9. Coffea arabica
  10. Coffea arenesiana
  11. Coffea augagneurii
  12. Coffea bakossii
  13. Coffea benghalensis
  14. Coffea bertrandii
  15. Coffea betamponensis
  16. Coffea bissetiae
  17. Coffea boinensis
  18. Coffea boiviniana
  19. Coffea bonnieri
  20. Coffea brassii
  21. Coffea brevipes
  22. Coffea bridsoniae
  23. Coffea buxifolia
  24. Coffea canephora (“Coffea robusta”)
  25. Coffea carrissoi
  26. Coffea charrieriana
  27. Coffea cochinchinensis
  28. Coffea commersoniana
  29. Coffea congensis
  30. Coffea costatifructa
  31. Coffea coursiana
  32. Coffea dactylifera
  33. Coffea decaryana
  34. Coffea dubardii
  35. Coffea ebracteolata
  36. Coffea eugenioides
  37. Coffea fadenii
  38. Coffea farafanganensis
  39. Coffea floresiana
  40. Coffea fotsoana
  41. Coffea fragilis
  42. Coffea fragrans
  43. Coffea gallienii
  44. Coffea grevei
  45. Coffea heimii
  46. Coffea homollei
  47. Coffea horsfieldiana
  48. Coffea humbertii
  49. Coffea humblotiana
  50. Coffea humilis
  51. Coffea jumellei
  52. Coffea kapakata
  53. Coffea kianjavatensis
  54. Coffea kihansiensis
  55. Coffea kimbozensis
  56. Coffea kivuensis
  57. Coffea labatii
  58. Coffea lancifolia
  59. Coffea lebruniana
  60. Coffea leonimontana
  61. Coffea leroyi
  62. Coffea liaudii
  63. Coffea liberica
  64. Coffea ligustroides
  65. Coffea littoralis
  66. Coffea lulandoensis
  67. Coffea mabesae
  68. Coffea macrocarpa
  69. Coffea madurensis
  70. Coffea magnistipula
  71. Coffea malabarica
  72. Coffea mangoroensis
  73. Coffea mannii
  74. Coffea manombensis
  75. Coffea mapiana
  76. Coffea mauritiana
  77. Coffea mayombensis
  78. Coffea mcphersonii
  79. Coffea melanocarpa
  80. Coffea merguensis
  81. Coffea millotii
  82. Coffea minutiflora
  83. Coffea mogenetii
  84. Coffea mongensis
  85. Coffea montekupensis
  86. Coffea montis-sacri
  87. Coffea moratii
  88. Coffea mufindiensis
  89. Coffea myrtifolia
  90. Coffea namorokensis
  91. Coffea neobridsoniae
  92. Coffea neoleroyi
  93. Coffea perrieri
  94. Coffea pervilleana
  95. Coffea pocsii
  96. Coffea pseudozanguebariae
  97. Coffea pterocarpa
  98. Coffea racemosa
  99. Coffea rakotonasoloi
  100. Coffea ratsimamangae
  101. Coffea resinosa
  102. Coffea rhamnifolia
  103. Coffea richardii
  104. Coffea sahafaryensis
  105. Coffea sakarahae
  106. Coffea salvatrix
  107. Coffea sambavensis
  108. Coffea sapinii
  109. Coffea schliebenii
  110. Coffea semsei
  111. Coffea sessiliflora
  112. Coffea stenophylla
  113. Coffea tetragona
  114. Coffea togoensis
  115. Coffea toshii
  116. Coffea travancorensis
  117. Coffea tricalysioides
  118. Coffea tsirananae
  119. Coffea vatovavyensis
  120. Coffea vavateninensis
  121. Coffea vianneyi
  122. Coffea vohemarensis
  123. Coffea wightiana
  124. Coffea zanguebariae

Conclusion

While there are 124 species of coffee, only two of them make up almost the entire world’s production. There was a recent study pointing out that many of these lesser-known species were at risk, since they only grow in small, specific, geographic areas and that climate change might make it impossible for them to thrive. That ended up being popularly reported as “Coffee is going extinct!”  Check out this post for more on that.

While I am not going to give in to hyperbole, losing this genetic diversity would be a very bad thing. Cross-breeding within plant species is a terrific way to combat habitat loss and improve disease resistance.

And I am for anything and everything that guarantees my morning cup is going to continue to hit my breakfast table.

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Tim

I am Tim Bruno, a former Kona coffee farmer promoting the soon to be released Procaffeination: A Coffee Lover’s Dictionary and several other coffee-related products. I will soon be adding a YouTube channel to my efforts. Stay tuned!

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