Home Roasting9 min read

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.

BrewedLate Coffee

Coffee Expert

#Kenya Gatugi #peaberry #home coffee roasting #Kaffelogic #roast profile #F-WSH 1500-2200 #washed Kenyan coffee

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.

Home roast case study
17 roasts · 5 profiles
Goal: fruity-bright

Kenya · Nyeri County · Washed · 1,900 MASL · PB · John Burton

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+

Dialed-in recipe
F-WSH 1500-2200
Level 2·120g batch
“closest i've ever been to the original rocket coffee. this taste really good. sweet and fruity nice balance.”

Winning batch R-087 · 2026-06-30

Roast loss
11.67%
DTR
15.4%
ROR pre-FC
28.6°/m
ROR dev
7.2°/m

Cup quality across 17 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-010R-014R-018R-044R-073R-087Roast 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.

1.41.61.822.22.42.6Roast level (higher = darker)40g60g80g100g120g140gBatch size
F-WSH 1500-2200
Rocket Gatugi
9minFilter
NCT Filter B
NCT Filter D
○ 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-010R-014R-018R-044R-073R-093Each series scaled independently (shape, not absolute overlay)
DTR
Roast loss
ROR pre-FC
ROR development

What the data taught us

  1. 1Batch size was the hidden variable — 60g loads underperformed 100–120g on the same profiles.
  2. 2F-WSH 1500-2200 at level 2.0 / 120g became the repeatable winner (sweet + fruity, closest to Rocket Coffee Gatugi).
  3. 3Name-matched Rocket Gatugi at 60g ran to ~30% DTR and muted fruit — profile name ≠ automatic win.
  4. 4Once dialed in, later batches are confirmations — no need to re-score every cup.
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.

Want to log a journey like this?

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Open roasting log

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, NCT)

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.

NCT Filter B and Filter D at 100g were mixed: B could taste dark/bitter early then improve with rest; D 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

SettingValue
ProfileF-WSH 1500-2200
Level2.0 (higher = darker on the Kaffelogic scale)
Batch size120g
Roast loss~11.7%
DTR~15.4%
ROR pre-FC~28.6 °C/min
ROR development~7.2 °C/min
Rest7–10 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)

  1. Don’t underload standard F-Series profiles at 60g and blame the green coffee.
  2. Don’t assume a name-matched profile wins — Rocket Gatugi underperformed F-WSH 1500-2200 here.
  3. Don’t cup washed Kenya too early — rest changes the story.
  4. 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

1

Load 120g green

Weigh 120g. Small 60g loads were the biggest source of inconsistency on this bean.

2

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.

3

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.

4

Rest 7–10 days

Rest before final judgment. Re-brew after rest before changing profile or level.

5

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?
On a Kaffelogic Nano 7e, F-WSH 1500-2200 at level 2.0 with a 120g batch size delivered the best fruity-bright cup after 17 attempts — sweet, balanced, and closest to a commercial Rocket Coffee Gatugi reference.
What batch size should I use for dense Kenyan peaberry?
Avoid 60g loads on standard F-Series profiles. 100–120g gave more stable heat transfer. Early 60g batches produced scorched exteriors, muted sweetness, or runaway development depending on the profile.
What DTR and roast loss work for washed Kenyan peaberry?
The winning roast landed around 15.4% DTR and ~11.7% roast loss, with pre-first-crack ROR near 29°C/min and development ROR near 7°C/min. Treat these as targets to approach, not rigid rules.
Is the Rocket Gatugi profile better than F-WSH for this bean?
In this log, F-WSH Rocket Gatugi at 60g ran to 30% DTR and tasted dark with little sweetness. The generic F-WSH 1500-2200 at proper load outperformed the name-matched profile for this bean and goal.
How long should washed Kenyan peaberry rest after roasting?
Plan on 7–10 days of rest before judging the cup. Several earlier batches improved after extra rest; bright washed Kenyans often taste harsh or incomplete when cupped too early.
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