We all know the look and smell of a coffee bean. However, do you know what the bean—if it is a bean at all—actually is? What do you think: are coffee beans legumes or nuts? Even some of the most avid coffee drinkers aren’t aware of coffee’s proper classification, but we’re here to set the record straight.
Coffee beans are not fruits, legumes, or even beans, even though we all call them that. In fact, the coffee beans that we consume come from the seed of the coffee plant’s fruit. You can think of them like a peach pit.
Understandably, there is a lot of confusion surrounding the correct term for coffee beans, mainly because most people don’t see coffee until it is already harvested and roasted. To make it simple for you, we will look at legumes, beans, nuts, and fruit in detail and explain why a bean is just a seed.
So Are Coffee Beans Legumes or Beans?
To understand why coffee beans are not actually legumes, we must first understand what the word truly means.
The term legume can refer to a whole plant or its fruit or seed. Only plants from the family Fabaceae, also known as Leguminosae, are legumes. This plant group includes soybeans, peanuts, chickpeas, lentils, and beans.
Wait, we include beans in the legume group?
While we generally use the term “bean” for anything small and oval or kidney-shaped, beans scientifically come from the Leguminosae family. Any so-called beans not from that family are not beans. It is also important to remember that not all legumes are beans. A bean falls into the legume category, but there are other kinds of legumes, like peas and soybeans.
If you are not sure if a seed is a legume, check to see if it grows in a pod. Think of how peanuts and peas grow. To access the part we eat, you break open the pod and find multiple seeds.
Coffee does not grow in a pod that breaks easily, which is a big hint that it’s not part of the legume family. Plus, botanically speaking, a plant of coffee does not fall into the Leguminosae family. Therefore, its fruit and seeds are not legumes or beans.
What about Nuts?
While legumes can be easily opened and have multiple seeds, nuts often hold just one seed, and you need a nutcracker to get them open.
Common nuts fall into the Fagaceae and Betulaceae family, unique from the Leguminosae group. Their hard outer shell is actually dried fruit.
Just like beans, we used the word “nut” for a wide variety of seeds, but in reality, the botanical term specifically refers to those whose shell does not open easily. For example, walnuts and almonds aren’t truly nuts!
Now, coffee beans are pretty hard, so do they classify as a nut?
Nope! Coffee beans are not nuts because they do not have a hard outer shell nor anything inside.
Fruits and Berries
If coffee isn’t a bean, legume, or nut, what about fruits or berries?
To help us answer this question, we need to look at the coffee plant before farmers harvest the beans.
The plant, while often referred to as a coffee tree, is more of a large bush. Its branches grow dozens of small, oval fruit that turn from green to a dark, purple-red. From this fruit, the farmers harvest a coffee bean.
We usually call the fruit a coffee cherry, while they are not really cherries.
So, regarding whether a coffee bean is a fruit, the answer is not technically.
The coffee bean that we roast and grind for our drinks comes from the fruit’s inside, so the bean itself is not a fruit, but rather a part of the fruit.
What about berries?
Interestingly, we also have a common misconception about berries. What usually comes to mind when we think about berries are blueberries, blackberries, and strawberries. However, on that list, only blueberries are botanically classified as berries.
Berries are a fleshy fruit with thin layers throughout (we’ll look more at these layers when talking about a coffee cherry’s anatomy). Common botanical berries include bananas, eggplants, and tomatoes.
If a berry needs to have fleshy layers, does a coffee cherry qualify?
No, the parchment around the coffee seed is stiff, so coffee beans are not berries.
The Botanical Classification of Coffee
The only clue to a coffee bean’s true identity that we have discovered so far is that it is part of a fruit. Let’s learn more about how botanists classify the coffee plant and what name we can correctly give a coffee bean.
The coffee fruit, or coffee cherry, is a drupe fruit. While a berry has three fleshy layers surrounding the seed, a drupe (or stone) fruit has a hard parchment layer.
Some common examples of drupe fruits are cherries, peaches, and mangoes. Remember when I said that a coffee bean is like a peach pit? While peaches and coffee cherries are vastly different in size, their anatomy is the same.
A coffee bean, in simple terms, is the seed of a drupe fruit. You can compare it to a cherry pit or mango seed.
An Inside Look at a Coffee Cherry
We’ve talked a lot about fruit layers and how slight differences in them determine fruit’s botanical classification. However, it can be hard to wrap your mind around the structure if you’ve only seen harvested coffee beans.
Let’s explore further the inside of the coffee cherries.
The cherries are about the size of a marble, and most have two seeds. However, some rare coffee blends are made specifically from single seeds since people believe that they have a better taste.
Nevertheless, the majority of coffee cherries, though, have two seeds. Each one has a silver skin around it called an epidermis. Surrounding that is the parchment layer, called an endocarp. This thin covering is the hard layer that separates drupe fruits from berries.
Then we have the pectin layer, followed by the juicy pulp, or mesocarp. The outer skin, or exocarp, covers the whole fruit.
The three main layers that botanists look at to classify fruits are the endocarp (parchment around the seed), mesocarp (pulp), and exocarp (skin). While a berry, like a banana, has a soft endocarp around the seed, coffee beans have a hard protective layer on theirs.
We just covered a ton of information about coffee plants, but there is still so much to learn about this incredible plant that gives us our morning energy boost.
To What Botanical Family Do Coffee Plants Belong?
We already mentioned that coffee plants do NOT belong to the Leguminosae (legumes) or the Fagaceae (nuts) family, so how can they be classified?
There is not one family that encompasses all drupe fruits since there are multiple kinds. Instead, coffee belongs to the Rubiaceae family. The complete classification would be as follows:
- Kingdom: Plantae
- Phylum: Tracheophyta
- Class: Magnoliopsida
- Order: Gentianales
- Family Rubiaceae
- Genus: Coffea
- Species: Arabica, Robusta, and Liberica
While you don’t need to memorize every coffee classification level, understanding the species’ coffee science will help in your purchases.
Coffee arabica is the most popular species in the world, covering about 70% of coffee production. Common varieties include Typica, Bourbon, and Jamaican Blue Mountain.
The Robusta and Liberica species are less common, but you can still find blends with these beans in your local store.
The next time you buy coffee, check what species and variety it is, as each one has a unique taste and flavor. Not all coffee comes from the same type of plant!
Why Do We Call Coffee Beans “Beans” If That Is Incorrect?
It can be quite confusing to call something a bean, and then later realize that it is not a bean at all. So, why do we use an incorrect name for beans coffee?
Most people do not study the botanical terms for different types of fruits and seeds, and when we see something that resembles our typical black bean, it makes sense to call it a bean as well.
Using the term “bean” is just a way that we all can recognize an object and relate it to things we already know. It’s just like how not all nuts and berries are actually nuts and berries.
Knowing the correct botanical terms can help us understand what we are eating and drinking, but most of the world will continue calling things by their incorrect name for the sake of popular understanding.
How Many Steps Does It Take to Harvest Coffee Beans?
The process of getting roasted coffee beans from the cherries is quite extensive.
- Plant the coffee trees
- Harvest coffee cherries
- Process the cherries with a wet method
- Dry the beans
- Mill them to remove the endocarp and sort them
- Export them as green coffee
- Use taste tests to ensure the quality
- Roast and grind the beans
While most coffee drinkers buy coffee that is pre-roasted and ground, many coffee lovers buy the coffee green after the milling process and roast them in their own homes to ensure freshness.