Every cup starts with the bean. The species, where it was grown, how it was roasted and how long ago it was roasted all show up in the cup before you choose a brewer or grinder. This guide explains those factors in plain terms and shows how to use them when buying and storing coffee at home. It draws on the National Coffee Association’s consumer resources and the FDA; we did not taste-test brands for this guide.
Arabica and robusta
Almost all commercial coffee comes from two species. The National Coffee Association (NCA) says arabica and robusta together make up more than 99% of commercial coffee, with arabica about 57% of world production and robusta about 43%.
| Arabica | Robusta | |
|---|---|---|
| Flavour (NCA description) | Fine, mild, aromatic | Strong, bold, with bitter undertones |
| Caffeine | Lower | About 50–60% more than arabica |
| Growing conditions | Cooler temperatures, roughly 59–75°F; generally 2,000–6,000 ft; killed by heavy frost | Warmer, constant 75–85°F; much lower altitudes; cannot withstand frost |
| Typical uses | Most specialty and single-origin coffee | Blends, instant coffee, some espresso blends |
Neither species is “better” in every use. Many espresso blends include some robusta for body and crema, and robusta is widely used in instant coffee. If a bag says “100% arabica”, it tells you the species, not the quality; growing, processing and roasting matter just as much. More detail is in our coffee bean types section.
Origins: what the region tells you
Coffee grows in a band around the equator, and growing region shapes flavour through climate, altitude, varieties and processing. The NCA’s regional descriptions give a useful starting point:
- Brazil, the largest producer by volume: clear, sweet, medium-bodied and low-acid.
- Colombia: consistently mild with well-balanced acidity.
- Guatemala: medium to full body, often described as almost spicy or chocolatey.
- Costa Rica: medium body and sharp acidity, often described as balanced.
- Ethiopia: full-flavoured and full-bodied, often with fruity, spicy or floral notes and lively acidity.
- Kenya: full body with sharp, fruity acidity and rich fragrance.
- Indonesia: rich, full body and mild acidity, sometimes earthy or spicy.
- Vietnam: mostly robusta, with low acidity and fuller body, often used in blends.
These are tendencies, not rules. A single farm can produce very different coffees from year to year, and processing (washed, natural, honey) changes the cup as much as the country does. Our coffee origins guides go region by region.
Roast levels
Roasting turns green seeds into the brown beans we brew. Roast level is mainly about flavour:
| Roast | Appearance (NCA) | Flavour | Common names |
|---|---|---|---|
| Light | Light brown, no oil on the surface | Subtle roast flavour, more acidity; shows the origin character | Blonde, cinnamon, city |
| Medium | Medium brown, non-oily | Stronger, more rounded flavour | American roast, breakfast blend |
| Dark | Shiny, dark, oily surface | Pronounced bitterness, less acidity | French, Italian |
A common misconception is that dark roast has more caffeine. The NCA notes that the rich flavour of dark roasts is not associated with caffeine levels, and that light roasts have slightly more caffeine. The bigger caffeine differences come from species (robusta versus arabica) and how much coffee you use. See roast levels for more.
Freshness and roast dates
Roasted coffee slowly loses aroma once exposed to air, light, heat and moisture. A “best by” date on the bag tells you when the seller expects quality to fall, while a “roasted on” date tells you how old the beans actually are; the roast date is more useful.
The NCA gives these guideline times for opened coffee in an airtight container:
| Coffee | Room temperature | Refrigerated | Frozen |
|---|---|---|---|
| Roasted whole beans | 1–3 weeks | About 2 weeks | 3–4 months |
| Ground coffee | 1–2 weeks | — | — |
| Unopened beans or ground | Until the best-by date | ||
That is why whole beans ground just before brewing usually taste fresher than pre-ground coffee: grinding exposes far more surface to air.
Storing coffee at home
The NCA’s storage advice comes down to four enemies: air, light, heat and moisture.
- Airtight: move beans to an airtight container, especially pre-ground coffee.
- Opaque: clear canisters let in light, which affects flavour.
- Cool and dark: avoid cupboards next to the oven or dishwasher and spots that get afternoon sun.
- Dry: coffee absorbs moisture and odours, so keep it sealed.
- Freezer, if you must: opinions differ. If you freeze, use a truly airtight container, take out only what you need for up to a week, and return the rest quickly before condensation forms.
Our coffee storage section compares containers and freezing methods.
Reading a coffee bag
| Label item | What it tells you |
|---|---|
| Roast date | How fresh the beans are; the most useful date |
| Origin (country, region, farm) | Single origin or a blend; more detail usually means more traceability |
| Species / variety | Arabica, robusta or a blend; varieties such as Bourbon or Typica |
| Process | Washed, natural or honey; affects fruitiness and body |
| Roast level | Light, medium or dark; sets the flavour direction |
| Tasting notes | The roaster’s description, a guide rather than added flavourings |
| Whole bean or ground (and grind size) | Whole bean keeps longer; pre-ground should match your brewer |
Buying advice, including how much to buy at once, is in buying coffee beans.
Caffeine: a note on amounts
The FDA cites 400 milligrams a day as an amount not generally associated with negative effects for healthy adults, but sensitivity varies widely. The FDA lists 113–247 mg for a 12-ounce cup of regular brewed coffee and about 2–15 mg for an 8-ounce decaf, showing how much the amount can vary. If you are pregnant, trying to become pregnant or breastfeeding, the FDA recommends asking your health care provider about limiting caffeine.
Putting it together
- Pick a roast level by flavour: light for brighter, origin-driven cups; medium for balance; dark for low acidity and roasty bitterness.
- Try origins with different profiles, for example a Brazil and a Kenya side by side.
- Buy whole beans in amounts you will use within a few weeks.
- Store them airtight, opaque, cool and dry.
- Grind just before brewing, matched to your method; see our grind size guide and brewing methods compared.
All bean guides are under Coffee Beans.
