How Long After First Crack Should You End the Roast?
Development time (from first crack start to roast end) is the primary control lever for roast level. Too short = underdeveloped/grassy. Too long = flat/dark. The 20–25% DTR rule is a useful starting framework.
⚡ Quick Answer
Development Time Ratio (DTR) = time from first crack to drop ÷ total roast time × 100%. Target range: 20–25% for most light-to-medium roasts. For a 10-minute total roast, that's 2–2.5 minutes after first crack. Light roasts: 15–20% DTR (drop shortly after crack begins). Medium: 20–25%. Medium-dark: 25–30%. Dark: 30%+ or into second crack.
🎯 Simpler Rule for Beginners: If you don't track DTR yet, use absolute time: drop 1–1.5 minutes after first crack for light roast, 2–3 minutes for medium, 3–4 minutes for medium-dark. Listen and smell — caramelized sweetness should be developing, not smoke.
⚙️ DTR by Roast Target
| Roast Level | DTR % | Absolute Time After FC | Flavor Profile |
|---|---|---|---|
| Light | 15–20% | 1–1.5 min | Bright, fruity, high acidity |
| Light-Medium | 20–22% | 1.5–2 min | Balanced, some sweetness, mild acidity |
| Medium | 22–25% | 2–2.5 min | Caramelized sweetness, body |
| Medium-Dark | 25–30% | 2.5–3.5 min | Bittersweet, chocolate, low acidity |
| Dark | 30%+ | Into 2nd crack | Smoky, bold, low origin character |
Note: These ranges assume a total roast time of 8–12 minutes. Very fast or slow roasts require proportional adjustments.
⚙️ Signs You Need More or Less Development
Underdeveloped (too little DTR)
- • Grassy, hay-like aroma
- • Sour, harsh, astringent cup
- • No sweetness
- • Papery finish
Fix: Drop later next batch, add 30–60 seconds after crack
Over-developed (too much DTR)
- • Flat, lacking brightness
- • Ashy, smoky character
- • Harsh bitterness
- • "Baked" or cardboard flavor
Fix: Drop earlier next batch, shorten post-crack time