Tetsu Kasuya 4:6 Method (iced)

Tetsu Kasuya · Pour-over · Hario V60 02

20 g → 150 g · 1 : 7.5 · 90 °C · 3:00 total · Medium grind

The 4:6 method flash-brewed: half the water, poured hot straight onto ice so the coffee chills instantly without going flat.

1. 0:00first pour — sweetness phase30 g
2. 0:40second pour60 g
3. 1:10third pour — strength phase90 g
4. 1:40fourth pour120 g
5. 2:10fifth pour150 g

Japanese-style flash brew: brew hot over 80 g ice in the server so the coffee chills instantly and keeps its aromatics. Half the water of the hot 4:6 (1:7.5 concentrate); the ice melts to roughly a 1:11.5 drink. First pour trades sweetness (less) for brightness (more).

Transcribed from Flash-chill iced coffee, 4:6 method — Tetsu Kasuya (YouTube) on 2026-07-07