Matcha Harvest Timing — Ichibancha First Flush
Ichibancha (first flush) matcha, harvested April–May, contains peak L-theanine and lowest catechin bitterness of the year. Later flushes (nibancha, sanbancha) have progressively lower amino acid content and higher bitterness.
| Measure | Value | Unit | Notes |
|---|---|---|---|
| First flush (ichibancha) harvest window — Uji | Late April – mid-May | Approximately 10–14 days of peak harvest conditions | |
| L-theanine: first flush vs. second flush | ~40–50% higher | Second flush (nibancha) late June–July; significantly lower L-theanine | |
| Number of harvests per year (tencha) | 1–2 | Most matcha-grade tea takes only ichibancha; some take nibancha for culinary grade | |
| Harvest window length | 10–15 | days | Narrow window; weather conditions can compress or extend this |
| Leaf age at harvest | 2–4 | days | Young unfurling leaves picked within days of budbreak |
| Summer flush bitterness increase | 2–3× | Nibancha leaves have more catechins and less amino acids due to heat and sunlight |
Timing is everything in matcha production. The first spring flush — ichibancha — is when tea plants produce the most prized young leaves, fresh from winter dormancy and not yet exhausted by the growing season. The quality gap between ichibancha and later harvests is measurable, significant, and the primary reason ceremonial-grade matcha commands a substantial price premium.
Why First Flush Is Superior
After winter dormancy, tea plants mobilize nitrogen stores from the root system into the emerging spring shoots. This nitrogen is converted into L-theanine and other amino acids in the young leaves. As the season progresses and temperatures rise:
- More sunlight accelerates catechin synthesis (more bitterness)
- Root nitrogen reserves are partially depleted
- Leaves mature and coarsen
- L-theanine and amino acid concentrations decline
The result: second-flush (nibancha) leaves, harvested in June–July, contain 40–50% less L-theanine and significantly more bitter catechins than first-flush leaves.
Climate Effects on Harvest Timing
Spring temperature determines when ichibancha begins. In Uji (Kyoto Prefecture), the traditional timing is late April to mid-May. Warmer springs push harvest earlier; cooler years delay it. Climate change has been advancing first-flush harvest timing by 4–7 days per decade across Japanese tea-growing regions.
Frost is the major risk: a late frost after budbreak can destroy the entire ichibancha harvest. Japanese tea farmers monitor weather forecasts carefully and use wind machines and helicopters in some regions to prevent frost damage by circulating warmer air from higher altitudes.
Hand vs. Machine Harvest
High-quality ceremonial matcha is typically hand-harvested (temizumi), with workers selecting only the top one to two leaves and a bud (ichimame, “one eye”). Machine harvesting is more common for culinary grades, which accept a wider range of leaf maturity and quality.