Species
& varietals
The raw genetic material. Which species, and which cultivar, sets the ceiling of what a coffee can be — before origin, processing, or roast get a say.
Two species that matter
Almost all the coffee worth tasting is one species. Knowing the split explains a lot about quality and price.
The varieties
Within Arabica, the variety (cultivar) sets genetic potential — the way a grape variety does in wine. Click through the ones worth knowing:
Hunt a variety
Find a variety on a bag
Check bags (or a specialty roaster’s site) for a named variety — Bourbon, Caturra, Gesha, "heirloom." Note how the pricier lots name it.
Splurge-taste, if you can
If you ever get the chance to try a well-made Gesha, take it — it’s the clearest single lesson that genetics matter.
Questions
Flashcards
Lock it in
From memory:
- Contrast Arabica and Robusta.
- Why does altitude track Arabica quality?
- What is Gesha and why does it matter?
- Name two Latin American workhorse varieties.
- State the hybrid resilience-vs-flavor trade-off.
Origins
& terroir
Where coffee grows shapes how it tastes — but remember the chain: origin is one strong signal, not destiny. Learn the great regional signatures and the role of altitude.
The great coffee regions
Three broad regions cover most of what you’ll drink, each with a recognisable signature. Click through:
Origin signatures are real and useful — but a natural-processed Colombian can out-fruit a washed Ethiopian. Read origin as a strong prediction that processing and roast can override. Altitude often tells you more about style than the country name alone.
Taste two regions
Pick a contrast
An African (Ethiopia/Kenya) against a Latin American (Colombia/Guatemala), both similar roast levels.
Predict, then taste
Expect the African brighter/floral, the Latin American sweeter/nutty. Brew identically and check.
Read the altitude
Look for an altitude figure (e.g. 1,800 m). Higher usually means the brighter, denser, more complex of your two.
Questions
Flashcards
Lock it in
From memory:
- Give the signature of East African coffee.
- Give the Latin American signature.
- What makes Indonesian coffee distinctive?
- How does altitude shape the cup?
- Why is origin a signal, not destiny?
Filter vs
espresso
The single most fundamental divide in coffee. Not a flavor difference — a difference in physics that produces almost two different beverages from the same bean.
Two ways to make coffee
Filter (gravity)
- Water passes through grounds under gravity — percolation or immersion.
- Larger volume, lower concentration; a clean, articulate cup.
- Brew ratios around 1:15–1:18.
- Best for tasting origin, acidity, and nuance.
- Methods: pour-over, French press, batch brew, AeroPress.
Espresso (pressure)
- ~9 bar forces water through a fine, compacted puck in ~25–30 s.
- Tiny volume, very high concentration, topped with crema.
- Brew ratio around 1:2 (e.g. 18 g → 36 g).
- Intense and textural; the base of all milk drinks.
- Unforgiving — magnifies every error (Session 18).
What pressure changes
Espresso’s pressure and fine grind do three things gravity can’t: they extract intensely in seconds, emulsify oils into crema, and concentrate the cup many times over. That’s why the same coffee is bright and floral as filter but dark and syrupy as espresso — and why a roaster may roast a coffee differently for each. The rest of this block maps the drinks that grow out of this divide; the brewing block (Sessions 14–18) teaches you to execute both sides.
Same bean, both ways
Brew one coffee two ways
If you have access to an espresso machine and a filter method, run the same coffee through both.
Compare concentration and character
Note how much more intense the espresso is — and how the flavor profile itself shifts, not just the strength.
Questions
Flashcards
Lock it in
From memory:
- State the fundamental divide.
- What does espresso use that filter doesn’t?
- How do filter and espresso ratios differ?
- What is crema and where does it come from?
- Why can one bean taste like two drinks?