Espresso
The fundamentals of espresso and how to dial in your shot.
Espresso is coffee brewed by forcing hot water under pressure (typically 9 bar) through finely ground coffee. It's the foundation of most café drinks and one of the most technically demanding brew methods.
Recipe
- Ratio
- 1:2
- Temperature
- 90–94°C
- Grind
- fine
- Total Time
- 25–30 sec
- Yield
- 36g (from 18g dose)
The Espresso Ratio
The most important variable in espresso is the brew ratio: the weight of your coffee in (dose) vs. coffee out (yield).
- Ristretto — 1:1 to 1:1.5 (thick, intense)
- Normale — 1:2 (balanced, most common)
- Lungo — 1:2.5 to 1:3 (lighter, more extraction)
A typical single shot uses 9g in / 18g out. A double uses 18g in / 36g out.
Always weigh your output, not just your input. Yield matters as much as dose for consistency.
Dialing In
"Dialing in" is the process of adjusting grind size to hit your target extraction time and yield.
The Dial-In Loop
Shot too fast (under ~22 sec) → grind finer
Shot too slow (over ~32 sec) → grind coarser
Shot on time but tastes off → adjust dose or yield ratio
Shot Diagnosis
| Result | Likely Cause |
|---|---|
| Sour, sharp, thin | Under-extracted — grind finer |
| Bitter, dry, harsh | Over-extracted — grind coarser |
| Salty | Possible channeling or bad water |
| Flat, no sweetness | Stale beans or too light a roast for espresso |
Channeling
Channeling occurs when water finds a path of least resistance through the puck rather than flowing evenly. It causes uneven extraction — parts of the coffee are over-extracted while others are under-extracted.
Prevention:
- Use a WDT tool (Weiss Distribution Technique) to break up clumps before tamping
- Tamp level and with consistent pressure (~15–20 kg)
- Use a puck screen or distribution tool
Channeling is the #1 cause of inconsistent espresso. A distribution tool is worth the investment.
Milk Steaming
For milk drinks, steam at a temperature of 60–65°C. Whole milk produces the best microfoam for latte art.
- Flat white / latte — silky microfoam, little texture
- Cappuccino — dry foam, more airy, 1:1:1 ratio of espresso:milk:foam