Cold brewing a sencha overnight in the fridge
15 February 2026 · 2 min read
Japanese greens brewed hot are a nervous business for me: 70 °C, 60 seconds, and still sometimes a cup that tastes of boiled spinach. Cold brewing removes most of the ways to get it wrong, so I tried the sencha that way: 8 g of leaf in a 750 ml glass bottle, filled with cold tap water, lid on, into the fridge at about 4 °C at eleven at night, strained at eight the next morning. Nine hours.
The result was pale green, cloudy, and startlingly sweet. Cold water pulls the amino acids out of the leaf and leaves most of the bitter compounds behind, and you can taste exactly that: a thick, savoury, almost broth-like sweetness, with the grassy top notes of the hot version but none of the astringency. It tasted expensive. It was the same 25 gram bag that had been giving me spinach.
A few comparisons from the same week, all at 8 g per 750 ml, strained after the hours given:
- 4 hours: lighter, more obviously green, slightly less sweet, very refreshing.
- 9 hours: the one described above, full and savoury.
- 14 hours: heavier, a faint bitterness returned, and a cooked note I did not like.
The drawback is the leaf afterwards. With hot brewing I would take four steeps from this leaf. After a cold brew the leaf is spent; a second cold fill produced something faintly green and sweet, drinkable but not worth the fridge space, and a hot steep of the used leaf was flat. So cold brewing uses the leaf about twice as fast per cup, which for a tea at this price is a real cost. I now keep it for the days when I want a bottle to carry rather than a session at the table.
Other notes: use a bottle you can get your hand into, because the wet leaf clings; strain through a fine mesh, not a tea strainer, because the fine Japanese leaf goes straight through the latter; and drink it within a day, because by the second morning the fridge had taken most of the aroma and left a thin grassy water.