How to Roast Kenya Gatugi Peaberry: 17 Roasts to a Dialed-In Cup
A data-backed case study of dialing in washed Kenya Gatugi peaberry: batch size as the hidden variable, profile experiments, and the final roast metrics that stuck.
The short answer: for washed Kenya Gatugi peaberry (~1,900m), the dialed-in home roast on a Kaffelogic Nano was F-WSH 1500-2200 at level 2.0 with a 120g batch — about 15% DTR, ~12% roast loss, and a cup that finally matched the sweet-fruity balance of a commercial Rocket Coffee Gatugi reference.
This is not a generic “how to roast Kenya” post. It is a case study from 17 logged roasts of John Burton’s Gatugi Peaberry (Nyeri, SL28/SL34/Batian/Ruiru 11, grade PB), with klog fingerprints, tasting notes, and the charts below.
Kenya · Nyeri County · Washed · 1,900 MASL · PB · John Burton
JB Kenya Gatugi Peaberry
Aroma of honeydew melon, black tea and brown sugar. Flavours of black tea, grapefruit and caramel. Long black tea aftertaste. Bright acidity and medium body. Score: 84+
Best so far: F-WSH 1500-2200 at level 1.9 to 2.0, 120 g — tasted good 5 of 5 times. Darker, at level 2.1 and 2.3, it tasted sour.
The journey
- Tasted good
- Had a fault
- Not tasted yet
What the roasts show
- Roast 1: F-WSH 1500-2200 at level 2.4, 60 g. 1 good.
- Then level 2.4 → 2.2: roast 2. 1 with a fault (sour).
- Then level 2.2 → 2.0: roast 3. 1 with a fault (sour).
- Then level 2.0 → 1.8: roast 4. 1 with a fault (sour).
- Then level 1.8 → 1.6: roast 5. 1 good.
- Then level 1.6 → 2.0, profile F-WSH 1500-2200 → F-WSH Rocket Gatugi: roast 6. 1 with a fault (roasty).
- Then profile F-WSH Rocket Gatugi → 9minFilter, load 60 g → 100 g: roast 7. 1 good.
- Then level 2.0 → 1.8: roast 8. 1 with a fault (sour).
- Then level 1.8 → 2.0, profile 9minFilter → F-WSH 1500-2200, load 100 g → 120 g: roast 9. 1 good.
- Then level 2.0 → 2.1: roast 10. 1 with a fault (sour).
- Then level 2.1 → 2.2: roast 11. 1 good.
- Then level 2.2 → 2.3: roast 12. 1 with a fault (sour).
- Then level 2.3 → 2.2, profile F-WSH 1500-2200 → Bright Filter, load 120 g → 100 g: roast 13. 1 good.
- Then level 2.2 → 2.5, profile Bright Filter → Rich Filter: roast 14. 1 with a fault (roasty).
- Then level 2.5 → 2.0, profile Rich Filter → F-WSH 1500-2200, load 100 g → 120 g: roasts 15–16. 2 good.
- Then load 120 g → 100 g: roast 17. 1 good.
- Then load 100 g → 120 g: roasts 18–19. 1 good, 1 not tasted.
- Then level 2.0 → 1.9: roast 20. 1 good.
- Then load 120 g → 60 g: roast 21. 1 good.
- Weight lost: good roasts 8.3%–14.2%, roasts with a fault 11.9%–14.5%.
- Time in the hot zone: good roasts 1:35–2:39, roasts with a fault 1:40–3:39.
- End temperature: good roasts 212 °C–223 °C, roasts with a fault 212 °C–220 °C.
- Good cups were tasted after 6–84 days of rest (12 tastings).
- The first good cup on F-WSH 1500-2200 at level 2.0, 120 g was roast 9 of 21.
This shows what differed in the roast. It does not say why the cup tasted different.
Recipes tried
F-WSH 1500-2200
Settled · 16 roasts · 1:35–2:00
- 1.6 · 60 g · 1 roast, Tasted good
- 1.8 · 60 g · 1 roast, Had a fault
- 1.9 · 60 g · 1 roast, Tasted good
- 1.9 · 120 g · 1 roast, Tasted good
- 2.0 · 60 g · 1 roast, Had a fault
- 2.0 · 100 g · 1 roast, Tasted good
- 2.0 · 120 g · 5 roasts, Tasted good
- 2.1 · 120 g · 1 roast, Had a fault
- 2.2 · 60 g · 1 roast, Had a fault
- 2.2 · 120 g · 1 roast, Tasted good
- 2.3 · 120 g · 1 roast, Had a fault
- 2.4 · 60 g · 1 roast, Tasted good
Rich Filter
Moved on · 1 roast · 3:05
- 2.5 · 100 g · 1 roast, Had a fault
Bright Filter
Moved on · 1 roast · 2:39
- 2.2 · 100 g · 1 roast, Tasted good
9minFilter
Moved on · 2 roasts · 2:11–2:26
- 1.8 · 100 g · 1 roast, Had a fault
- 2.0 · 100 g · 1 roast, Tasted good
F-WSH Rocket Gatugi
Moved on · 1 roast · 3:39
- 2.0 · 60 g · 1 roast, Had a fault
The recipe that stuck
- Profile
- F-WSH 1500-2200
- Level
- 2.0
- Batch
- 120g
- 11.67%
- 1:49
- End temperature
- 213°C
- Winning batch
- R-087 · 2026-06-30
closest i've ever been to the original rocket coffee. this taste really good. sweet and fruity nice balance.
Compare two recipes
- Hot zone about the same (1:45 vs 1:47)
- 3.7 points less weight lost (8.3% vs 12.0%)
- End temperature about the same (212 °C vs 213 °C)
This shows what differed in the roast. It does not say why the cup tasted different.
Numbers are averages over each recipe's roasts.
What the roasts taught
- Batch size was the hidden variable — 60g loads underperformed 100–120g on the same profiles.
- F-WSH 1500-2200 at level 2.0 / 120g became the repeatable winner (sweet + fruity, closest to Rocket Coffee Gatugi).
- Name-matched Rocket Gatugi at 60g ran to ~30% DTR and muted fruit — profile name ≠ automatic win.
- Once dialed in, later batches are confirmations — no need to re-score every cup.
Where the good cups live
Roast level against batch size. Colour is the profile; a larger dot is a roast that tasted good.
Roast mechanics across the roasts
Roast loss, hot zone and end temperature for each logged roast. Each line has its own scale, so compare shapes, not heights.
Roast goal
Roast light (just after first crack) to preserve the bright grapefruit acidity and black tea complexity. Development should be quick post-crack to caramelize sugars without muting the origin character. Aim for a cup that sparkles with citrus, finishes with clean tea notes, and carries honeydew sweetness through the mid-palate.
The counts in this guide are from when it was written. Roasts added since then are in the Kenya Gatugi Peaberry roast log, which lists every attempt and how it tasted.
What is Kenya Gatugi peaberry?
Gatugi Factory sits in Nyeri County between Mt. Kenya and the Aberdare Range, under the Othaya Farmers’ Cooperative Society. Peaberry (PB) is a denser single-seed screen — it needs honest heat transfer and careful development if you want brightness and sweetness.
Cup targets for this lot: honeydew, black tea, brown sugar on the nose; black tea, grapefruit, and caramel in the cup; long tea finish; bright acidity; medium body (cupping score ~84+).
Roast goal: fruity-bright — light enough to keep grapefruit and black tea, developed enough to avoid sour metallic edges.
The journey in three acts
1. Early 60g F-WSH experiments (R-010 → R-015)
First batches used F-WSH 1500-2200 at levels 2.4 → 1.6 on 60g. Structure was often fine (DTR ~13–17%, healthy ROR), but the cup swung between:
- subtle fruit with darker bitterness (too dark)
- strong fruit without sweetness
- sour, unpleasant acidity (too light / underdeveloped relative to goal)
Lesson: level alone could not fix a thermal-load problem. 60g on a standard profile exaggerated preheat and made “light vs dark” hard to separate from uneven development.
2. Name-matched and alternative profiles (Rocket Gatugi, 9minFilter, Bright Filter and Rich Filter)
F-WSH Rocket Gatugi at 2.0 / 60g looked promising on paper. In the log it ran to ~30% DTR and tasted dark, with muted fruit and almost no sweetness — the worst miss in the set.
9minFilter at 100g got closer (nice fruit) but still lacked the Rocket reference’s sweet–fruit balance.
Bright Filter and Rich Filter at 100g were mixed: Bright Filter could taste dark/bitter early then improve with rest; Rich Filter got “pretty close” to the commercial reference but still had sour-metallic edges.
3. Proper load + F-WSH 1500-2200 (R-035 → R-087)
Once batch size moved to 120g, the same F-WSH family started stacking wins. Notes shift from “unpleasant sour” to “nice and fruity, push sweetness a little more,” then to the winning note on R-087:
closest i've ever been to the original rocket coffee. this taste really good. sweet and fruity nice balance.
Later batches R-093 and R-099 repeated the same settings to confirm.
The dialed-in recipe
| Setting | Value |
|---|---|
| Profile | F-WSH 1500-2200 |
| Level | 2.0 (higher = darker on the Kaffelogic scale) |
| Batch size | 120g |
| Roast loss | ~11.7% |
| DTR | ~15.4% |
| ROR pre-FC | ~28.6 °C/min |
| ROR development | ~7.2 °C/min |
| Rest | 7–10 days before final judgment |
Use these metrics as a corridor, not a GPS pin. If your machine, ambient temp, or green moisture differs, keep profile/level/load and nudge until DTR and loss sit near this band and the cup tastes sweet-fruity rather than sour or dark-bitter.
What not to do (on this bean)
- Don’t underload standard F-Series profiles at 60g and blame the green coffee.
- Don’t assume a name-matched profile wins — Rocket Gatugi underperformed F-WSH 1500-2200 here.
- Don’t cup washed Kenya too early — rest changes the story.
- Don’t chase only lighter levels when sweetness is missing; often you need better development or a better thermal mass, not a lower dial.
How this connects to BrewedLate
Every chart above is built from the same data the app already stores: green coffee goals, roast batches, klog fingerprints (DTR, ROR, drop/FC temps), and freeform tasting notes. The long-term idea is simple: once a coffee is dialed in, publish a case study page like this automatically — content that only someone who actually roasted the bean can write.
If you roast at home and want a log that turns into insight (and eventually pages like this):
Track every roast, improve every batch
BrewedLate helps home roasters log green coffee inventory, roast batches, Kaffelogic curves, and get AI recommendations — all in one web-based tool.
Related reading
How to roast Kenya Gatugi peaberry on a Kaffelogic Nano
Dialed-in recipe from a 17-roast home log for washed Kenya Gatugi peaberry
Load 120g green
Weigh 120g. Small 60g loads were the biggest source of inconsistency on this bean.
Select F-WSH 1500-2200 at level 2.0
Altitude-matched washed F-Series profile at a light-medium level preserves grapefruit and black tea while developing enough sweetness.
Aim for healthy mechanics
Target roughly 15% DTR, ~12% roast loss, pre-FC ROR in the high 20s °C/min, and development ROR around 7°C/min.
Rest 7–10 days
Rest before final judgment. Re-brew after rest before changing profile or level.
Brew filter and taste for sweet fruit balance
Look for honeydew/black tea aroma, grapefruit and caramel, clean tea finish — not sour metallic notes or dark bitterness.
Frequently Asked Questions
What is the best roast profile for Kenya Gatugi peaberry?
What batch size should I use for dense Kenyan peaberry?
What DTR and roast loss work for washed Kenyan peaberry?
Is the Rocket Gatugi profile better than F-WSH for this bean?
How long should washed Kenyan peaberry rest after roasting?
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