Home roast case study
14 roasts · 5 profiles
Goal: origin-clarity

How to Roast Ethiopia Yirgacheffe Grade 2: NCT Filter E Recipe

Dialing in Ethiopia Yirgacheffe Grade 2 — 14 logged home roasts with real metrics

Ethiopia · Yirgacheffe · Washed · 1,700-2,200 MASL · G2 · John Burton

Aroma of dried red fruits, citrus and vanilla biscuit. Flavours of toasted tea, lemon zest, caramel, spiced cookies and floral notes. Roasted nuts and caramel aftertaste. Low acidity and medium body. Score: 82.5+

Dialed-in recipe
NCT Filter E
Level 2.4·100g batch
“This is not bad, it's smooth, it's nice, it's a little bit fruity… better than the 91 roast.”

Winning batch R-090 · 2026-07-09

Roast loss
13.6%
DTR
10.8%
ROR pre-FC
31.2°/m
ROR dev
7.7°/m

Cup quality across 14 attempts

Each point is a roast scored from tasting notes (1 = miss, 5 = dialed in). The series stops at the teal halo — once dialed in, later repeats aren’t scored the same way.

12345Cup qualityR-011R-019R-031R-042R-057R-070R-090Roast attempt →

Where the good cups live

Roast level vs batch size. Color = profile family; larger dots = better cups. Notice how quality clusters once batch size moves to 100–120g.

1.522.53Roast level (higher = darker)40g60g80g100g120g140gBatch size
F-WSH 1500-2200
NordicLight
NCT Filter E
NCT Filter D
NCT Filter B
○ size = cup quality

Roast mechanics that stuck

DTR, roast loss, and rate-of-rise across attempts with klog data. Each series is scaled on its own axis so shapes are comparable.

R-011R-019R-031R-042R-057R-070R-090R-096Each series scaled independently (shape, not absolute overlay)
DTR
Roast loss
ROR pre-FC
ROR development

What the data taught us

  1. 160g F-WSH loads stayed green — thermal mass mattered as much as level.
  2. 2Cranking F-WSH / NordicLight darker (3.0–3.3) did not fix underdevelopment; it often stayed grassy or went bland.
  3. 3NCT Filter E at ~2.4 / 100g first delivered smooth fruit without green (R-090) — better than Filter B/D at similar levels.
  4. 4Still a work in progress: fruit is there but bloom still a touch dark; R-096 at 2.2 is the lighter fine-tune.
Roast goal: Roast light to medium-light (ending around 400-410°F / 204-210°C) with a gentle approach. Drop just after first crack completes to preserve the delicate tea, floral, and citrus notes. Avoid pushing into second crack or developing heavy caramelization. Aim for a bright, clean cup that showcases the Yirg character.

Want to log a journey like this?

Track profiles, klog metrics, and tasting notes until the cup clicks.

Open roasting log