Tetsu Kasuya memenangkan World Brewers Cup 2016 dengan metode ini. Inti: 40% air pertama kontrol flavor balance (sweetness vs acidity), 60% berikutnya kontrol strength (strong vs mild).

Konsep 4:6

Total air dibagi 5 pour:

Pour 1-2 (40%) — kontrol rasa (acidity vs sweetness ratio)
Pour 3-5 (60%) — kontrol strength (diatur per-pour timing)

Equipment

Hario V60-02 Ceramic atau V60-02 Plastic
Hario VCF-02-100W filter paper rinsed
Kettle gooseneck variable temp: Fellow Stagg EKG atau Timemore Fish Smart 600ml
Scale 0.1g + timer
Grinder medium-coarse (sedikit lebih kasar dari V60 standard)

Resep Default

Dose: 20g
Water: 300g (1:15)
Grind: medium-coarse
Temp: 92°C
Total time: 3:30 (drawdown termasuk)

Step-by-Step

Pour 1 (0:00 — 0:45) — 60g air

Bloom + first flavor pour. Center circle gerak perlahan. Brighter/acidic → pour kecil di sini (misal 50g). Sweet dominance → pour besar (misal 70g).

Pour 2 (0:45 — 1:30) — 60g (total 120g)

Continue pour kedua. Selesai pour 2 = 40% dari total water (120g) tuntas.

Pour 3 (1:30 — 2:00) — 60g (total 180g)

Start strength pour. Pour cepat di tengah.

Pour 4 (2:00 — 2:30) — 60g (total 240g)

Continue strength.

Pour 5 (2:30 — 3:00) — 60g (total 300g)

Final pour. Hentikan saat tepat 300g.

Drawdown (3:00 — 3:30)

Tunggu sampai bed kopi rata di bawah (flat bed = evenly extracted).

Kontrol Rasa

Lebih manis (sweetness↑)

Pour 1: 50g → 70g (pour lebih besar di awal)
Pour 2: 60g → 50g (balance)

Lebih bright / acidic

Pour 1: 70g → 50g
Pour 2: 60g → 70g

Lebih strong

Pour 3-5: 3 pour ubah jadi 2 pour (90g + 90g) = extraction lebih pendek interval
Total time tetap 3:00-3:30

Lebih mild

Pour 3-5: 3 pour ubah jadi 4 pour (40g + 40g + 40g + 60g) = extraction lebih lambat

Common Mistakes

Pour tidak ke tengah → channeling di dinding
Pour berhenti di tengah pour (ragu) → under-extract patch
Suhu salah (<88°C) → sour mayor. Kalau >95°C → bitter
Grind terlalu halus → drawdown lambat, lewat 4:00 = over-extract
Grind kasar → drawdown <3:00 = under-extract

Variasi Regional

Tetsu metode-nya berkembang per coffee origin:

Ethiopia light roast: sweetness mode (pour 1 besar)
Sumatra dark: strength mode (pour 3-5 cepat)
Kenya washed: balanced default

Sumber

Tetsu Kasuya — 2016 WBrC winning recipe (official)
James Hoffmann — "The 4:6 Method Explained"
European Coffee Trip — Tetsu interview