# What Is Coffee?

> Coffee is the roasted seed of a fruit, brewed in water. The whole chain from cherry to cup, and a map of everything else on this site.

Topic: Beans & Origins  
Published: 2026-08-30T10:10:00-04:00  
Updated: 2026-08-30T10:10:00-04:00  
Author: Mical Robert, Editor (https://trysix.online/author/mical-robert)  
Canonical: https://trysix.online/what-is-coffee

## The short answer

A drink made by brewing the roasted, ground seeds of the coffee plant. Those seeds grow two to a fruit inside a small red cherry. Nearly all of it comes from two species, arabica and robusta, grown in a band around the equator.

## Key takeaways

- A coffee bean is a seed, not a bean, and it grows inside a fruit.
- Two species account for essentially all commercial coffee: arabica and robusta.
- Roasting creates the flavour. Green coffee is grassy and essentially undrinkable.
- Brewing is extraction: dissolving soluble material out of ground coffee into water.

Coffee is the second thing most of us do every morning and one of the least examined. It is a fruit seed, roasted until it develops a flavour it did not previously have, then steeped in water. Everything anyone argues about is one of those steps, and this page is the map.

## The plant

Coffee grows on evergreen shrubs of the genus Coffea, which in cultivation are usually kept to two or three metres so the fruit can be picked. The plants flower white and fragrant, and the fruit that follows takes seven to nine months to ripen from green to deep red.

Each cherry contains two seeds, flat sides facing each other. Those seeds are what we call coffee beans, and they are the only part used. Occasionally a cherry produces a single rounded seed instead of two — a peaberry — which some roasters separate and sell on its own.

> **The one-line version** — Coffee is a fruit seed, dried, roasted until it develops flavour, ground, and steeped in water. Every argument about coffee is an argument about one of those five steps.

## From cherry to cup

**Figure: The chain, in months from flowering**

| Item | Value |
| --- | --- |
| Flowering | 0 |
| Cherry ripens | 8 |
| Picked and processed | 9 |
| Dried, milled, graded | 10 |
| Shipped and roasted | 13 |
| Ground and brewed | 14 |

_Approximate. Only the last two steps happen anywhere near you, and only the last one happens in your kitchen._

Most of that chain is invisible to the drinker, and most of the flavour is decided in it. [How coffee is made](https://trysix.online/how-coffee-is-made) follows the processing steps in detail, and [where do coffee beans come from](https://trysix.online/where-do-coffee-beans-come-from) covers the geography.

## The two species

**Arabica and robusta, the two species that account for essentially all commercial coffee.**

|  | Arabica | Robusta |
| --- | --- | --- |
| Share of world production | Majority | Most of the remainder |
| Caffeine by weight | ~1.2–1.5% | ~2.2–2.7% |
| Grows at | Higher altitude, cooler | Lower altitude, hotter |
| Disease resistance | Lower | Higher |
| Flavour | Sweeter, acidic, aromatic | Harsher, grainy, more bitter |
| Typical use | Speciality and most bagged coffee | Instant, espresso blends, budget |

Two further species, liberica and excelsa, exist commercially but in very small volumes. [Types of coffee beans](https://trysix.online/types-of-coffee-beans) covers all four and what 'single origin' and 'blend' actually mean.

## Why roasting matters

Green coffee beans are dense, pale and taste of hay. Everything recognisable as coffee flavour is created by roasting, which drives off moisture and triggers the Maillard reaction and caramelisation, building hundreds of aromatic compounds that were not present before.

How far you take that process is the roast level. Stop shortly after first crack, around 385°F, and you have a [light roast](https://trysix.online/what-is-a-light-roast-coffee) that keeps the character of where it grew. Carry on to second crack near 435°F and you have a [dark roast](https://trysix.online/what-is-dark-roast-coffee) where roast flavour dominates. Neither is better; they are different trades.

> **The persistent myth** — Dark roast is not stronger in caffeine. Roasting degrades a small amount, so light roast holds marginally more by weight — though dark roast can win by scoop, because the beans are less dense. [Light vs dark roast](https://trysix.online/light-vs-dark-roast) has the arithmetic.

## What brewing actually is

Brewing is extraction: water dissolving soluble material out of ground coffee. About 30 percent of a roasted bean is water-soluble, and a well-made cup extracts around 18 to 22 percent of the bean's mass. Below that range the cup tastes sour and thin; above it, bitter and harsh.

Every brewing method is a different way of controlling how much gets extracted and into how much water. That is why the same beans taste so different as espresso and as filter — one dissolves a similar proportion into a fraction of the water.

**The major brewing methods and what distinguishes them.**

| Method | Mechanism | Ratio | Time |
| --- | --- | --- | --- |
| Drip / pour-over | Gravity through a filter bed | 1:16 | 3–6 min |
| French press | Full immersion, mesh filter | 1:16 | 4 min |
| Espresso | ~9 bar pressure | 1:2 | 25–30 sec |
| Moka pot | ~1.5 bar steam pressure | 1:8 | 3–5 min |
| Cold brew | Cold immersion | 1:8 or stronger | 12–24 h |
| Instant | Already brewed, then dried | n/a | Seconds |

If you only read one other page here, make it [how to make the perfect cup of coffee](https://trysix.online/how-to-make-a-perfect-cup-of-coffee) — it covers the five variables that decide nearly everything about how a cup tastes.

## Caffeine

Caffeine is a natural insecticide the plant produces, and it is why anyone drinks coffee in the morning. An 8 oz cup of brewed coffee averages about 95 mg; a single espresso shot about 63 mg; a cup of decaf about 2 mg.

Those averages hide a wide spread, because dose, species, grind and brew time all move the figure. The FDA cites 400 mg a day as not generally associated with negative effects for healthy adults — a population reference that does not apply during pregnancy, to children, or to people with certain cardiac or anxiety conditions. [How much caffeine is in a cup of coffee](https://trysix.online/how-much-caffeine-in-a-cup-of-coffee) has the full tables.

## Where to go from here

- Making it better: [how to make the perfect cup of coffee](https://trysix.online/how-to-make-a-perfect-cup-of-coffee) and [how to grind coffee beans](https://trysix.online/how-to-grind-coffee-beans).
- Making it without equipment: [how to make coffee without a coffee maker](https://trysix.online/how-to-make-coffee-without-a-coffee-maker).
- Understanding espresso: [what is espresso](https://trysix.online/what-is-espresso) and [types of coffee drinks](https://trysix.online/types-of-coffee-drinks).
- Buying beans: [where to buy coffee beans](https://trysix.online/where-to-buy-coffee-beans) and [the best coffee for beginners](https://trysix.online/best-coffee-for-beginners).
- Keeping it fresh: [how to store coffee beans](https://trysix.online/how-to-store-coffee-beans).

## Frequently asked questions

### Is a coffee bean actually a bean?

No. It is the seed of a fruit — a small red cherry that grows on an evergreen shrub of the genus Coffea. Each cherry normally contains two seeds with their flat sides facing each other. They are called beans because of their shape.

### What are the two main types of coffee?

Coffea arabica and Coffea canephora, the latter sold as robusta. Arabica makes up the majority of world production and is sweeter and more aromatic; robusta is hardier, harsher-tasting and carries roughly twice the caffeine.

### What does roasting do to coffee?

It creates the flavour. Green coffee beans taste grassy and are essentially undrinkable. Roasting drives off moisture and triggers browning reactions that build hundreds of aromatic compounds, while progressively degrading the acids present in the green bean.

### How is coffee brewed?

By dissolving soluble material out of ground coffee into water. About 30 percent of a roasted bean is soluble, and a good cup extracts 18 to 22 percent of its mass. The brewing method determines how much is extracted and into how much water.

## Sources

- [What Is Coffee?](https://www.ncausa.org/About-Coffee/What-is-Coffee) — National Coffee Association USA. Supports the botanical description of the coffee plant, the cherry and the two commercial species.
- [Coffee Standards](https://sca.coffee/research/coffee-standards) — Specialty Coffee Association. Supports the extraction percentage range that defines a well-brewed cup.
- [Spilling the Beans: How Much Caffeine is Too Much?](https://www.fda.gov/consumers/consumer-updates/spilling-beans-how-much-caffeine-too-much) — U.S. Food and Drug Administration. Supports the per-serving caffeine figures and the 400 mg daily reference.

## Related articles

- https://trysix.online/how-coffee-is-made
- https://trysix.online/where-do-coffee-beans-come-from
- https://trysix.online/types-of-coffee-beans
- https://trysix.online/how-to-make-a-perfect-cup-of-coffee

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