Summary of "Настройка помола кофе для эспрессо"

Summary — key points and practical steps for adjusting espresso grind (Nikolai Strelnikov)

Grinding adjustment is a normal, ongoing part of espresso preparation because coffee changes over time (degassing, oxidation, density shifts) and with the environment.
Extraction happens particle-by-particle. Finer particles expose more surface area so they extract faster and more intensely; coarser particles extract slower and increase water bypass between particles.
Important distinction: fast water flow ≠ fast extraction. Coarse grind → fast flow but often underextracted. Fine grind → slow flow but stronger per-particle extraction.

Basic formula: input (ground coffee mass) × yield coefficient = output (drink mass).
- Typical coefficient range: ~1.8–2.4 (commonly ≈2).
- Example: 20 g in → ~42 g out (coefficient ≈ 2.1).
Typical espresso brew time worldwide: 20–30 seconds. Speaker’s working range with soft water (~60 ppm) is ~27–28 s.

Keep dose (input) constant when adjusting grind — do not change dose to “fix” flow. Changing dose alters brew ratio and usually worsens taste compared to properly adjusting grind.
Prioritize controlling output weight (grams/ratio) with grind adjustments; brew time is secondary and a reflection of grind.
Suggested shop tolerances:
- High standard: ±0.1 g and ±1 s.
- Many shops accept larger tolerances: ±1–2 g and ±1–2 s (or more).

Displayed grinder numbers are only starting points; scales differ between machines and may wrap around.
Make very small changes — often in tenths (e.g., 3.1 → 3.2). Top-end grinders adjust in microns and may be motor-driven.
Recommended maximum adjustment step when dialing in: about 0.1–0.2 units at a time, especially when going finer.
Reducing grind size too much at once can jam the grinder.

Keep dose constant (example: 20 g).
Purge or ensure there is coffee in the burrs — don’t test on empty burrs.
Grind a test portion, distribute, tamp, wipe the tray, and brew.
Record: grind setting, input dose, output weight, brew time. (A simple log: grind — output — time.)
Interpret results:
- Brew time > target (water too slow) → grind too fine → coarsen slightly (increase grind number).
- Brew time < target (water too fast) → grind too coarse → make finer (decrease grind number).
- If output weight is off but time looks on-target, focus on adjusting grams first — it still indicates grind mismatch.
After each grind change, purge one (or sometimes 1.5) full portions so the new setting is in effect.
Re-weigh the portafilter (watch for accumulated coffee/water drops that alter weight). Repeat until within acceptable error.
When very close, brew a second shot at the same setting to verify repeatability before making further changes.

Do not compensate for a coarse or fine grind by changing dose — that preserves incorrect extraction.
Keep a log of grind settings, outputs, and times. Logs help track changes, identify issues (e.g., new burrs change calibration), and allow smooth handoff between staff.
Don’t rely only on the stopwatch; deviations in weight/ratio can change taste significantly.
Expect significant re-dialing when changing burrs or machines.

Starting point: grind ≈ 3.1 at 20 g dose, target ~42 g in 27 s.
Tested and adjusted: 3.2 (coarser) then 3.15 to find a setting that gave ~41–42 g in ~25–27 s.
Final acceptable result: ~41 g in 26 s (within ≈ ±1 g / ±1 s) — considered ready for service.

Speaker: Nikolai Strelnikov.
Training offered in Saint Petersburg and Moscow; trainers mentioned: Vika Rovinskaya and Veronica (also offers remote/online training).
Examples/mentions: different basket sizes (18 g vs 19–20 g), soft water ~60 ppm, and modern high-end micrometer/electric grinders.