Roasting Wet-Hulled (Giling Basah) Indonesia: Body vs Clarity

What Is Wet-Hulled (Giling Basah)?

Wet-hulling (giling basah) is a traditional Indonesian processing method used widely in Sumatra, Aceh, parts of Sulawesi and other regions with humid, rainy climates. Instead of fully drying parchment to ~10–12% moisture before hulling like fully washed coffees, producers hull the coffee much earlier—often around 30–40% moisture—then finish drying the exposed green bean.

Why? Because constant rain, limited patio space and infrastructure make it difficult to dry parchment slowly to specialty standards. Wet-hulling allows producers and collectors to move coffee through the system faster, even when the weather is unpredictable.

This early hulling and fast drying give wet-hulled coffees their signature:

• Big, syrupy body and lower perceived acidity.
• Earthy, herbal, woody and spice notes that many drinkers associate with “Sumatra”.
• Higher risk of musty, baggy or muddy cups if drying or storage are not well controlled.

As a roaster, your goal isn’t to turn wet-hulled lots into washed Africans—but to tune profiles so you get structured body, sweetness and pleasant spice, with as much clarity as the green coffee can reasonably deliver.

Wet-hulled coffees often arrive with slightly different physical characteristics compared to high-grown washed Central or African coffees. Depending on region and preparation, you may see:

• Moderate density rather than very high; beans can be more brittle.
• Visible color variation and silver skin due to early hulling and rougher drying.
• Greater sensitivity to very aggressive charge temperatures and drum environments.

In the roaster, wet-hulled Indonesians often:

• Respond well to gentle but committed heat—not too aggressive, not weak.
• Benefit from steady airflow to keep earthy notes clean instead of smoky or musty.
• Develop body easily, but lose clarity quickly if roasted too dark or too slow.

It’s useful to think of them as their own category, but with lessons borrowed from:

The rest of this guide explains how to shape profiles so you maintain the classic Indonesian depth your customers expect, while lifting as much sweetness and definition as the green coffee allows.

The main challenge with wet-hulled coffees is finding the point where body is fully developed but flavors have not collapsed into a single dark, earthy note. Profiles that are too gentle can taste grassy or woody; profiles that are too aggressive can taste ashy and flat.

1. Charge & Drying — Respect The Structure

Because many wet-hulled lots are moderate in density and sometimes more brittle, extremely high charge temperatures can cause tipping and scorch without giving you better flavor.

• Charge a bit below your highest natural/washed profiles, but not weak—aim for a confident start.
• Keep the rate of rise (ROR) climbing steadily early, avoiding sudden gas spikes.
• Use moderate airflow in drying to remove humidity and early smoke.

Drying (to yellow) often sits around 4:00–4:45 for typical drum roasts. Too fast and you risk uneven internal drying; too slow and you extend total roast time into baked territory.

2. Maillard — Building Body Without Mud

Maillard is where you build the classic wet-hulled attributes: chocolate, spice, tobacco, cedar. It’s also where things can become muddy if you simply “park” the roast at low energy for too long.

• Target Maillard windows of roughly 4:00–5:00 depending on batch and drum size.
• Keep ROR gently declining—never flat or rising for long stretches.
• Maintain adequate airflow so smoke and heavier volatiles don’t accumulate.

If your cup tastes like raw spice, green wood or paper, Maillard may be too short or too cool. If it tastes like muddy dark chocolate with no definition, Maillard plus development may be too long and flat.

3. Development — Stop Before Everything Turns Brown

Wet-hulled coffees build color and body quickly. It’s tempting to push deeper looking for sweetness, but beyond a certain point you get more roast taste than coffee taste.

• Filter: aim for ~1:10–1:40 after first crack (roughly 14–18% of total time).
• Espresso: aim for ~1:30–2:10 after first crack (roughly 18–22% of total time).

Think “medium and articulate” rather than “very dark and anonymous”. You want the cup to say “Sumatra” or “Gayo” clearly, not just “dark roast”.

Filter Roast — Comfort Cups With Shape

As filter coffees, wet-hulled Indonesians are ideal when you want comfort, warmth and weight—but you still want the cup to feel deliberate and clean.

• Roast to a light–medium or medium level with 14–18% development.
• Highlight cocoa, dark chocolate, tobacco, cedar, gentle spice with a hint of dried fruit.
• Use brew ratios around 1:15–1:16 at 92–96 °C, adjusting grind to keep extraction sweet, not drying.

If filter cups taste too earthy or muddy, try slightly shorter development and a touch more energy in Maillard to lift sweetness. If they’re **thin and woody**, you may need slightly deeper development or a slower Maillard.

Espresso Roast — Dense Chocolate & Spice

For espresso, wet-hulled Indonesians are classics: dense crema, chocolatey body, low-to-medium acidity and notes that stand up in milk.

• Roast to medium with 18–22% development.
• Target dark chocolate, molasses, cedar, baking spice over vegetal or ashy notes.
• Start with 1:2–1:2.1 ratios at ~28–32 seconds and adjust dose and grind to balance sweetness and texture.

If espresso tastes astringent or woody, check that you’re not under-developing or under-extracting. If it tastes ashy, your roast may be too dark or development too long.

Some flavor issues in wet-hulled coffees are baked into the green coffee by climate and processing; others are amplified or softened by your profile. Being able to separate the two is an important roasting skill.

1. Muddy / Earthy Cups

Symptoms: dull, indistinct flavors; the cup tastes like “brown,” with little separation.

Possible sources:

• Long, low-energy roasts with flat ROR in Maillard and development.
• Overly dark end color in search of sweetness.
• Green coffee with inherently low clarity.

Adjustments: shorten total roast time by 30–60 seconds, keep ROR gently declining rather than flat, and consider finishing slightly lighter while preserving development percentage.

2. Musty / Baggy Notes

Symptoms: sack-like, dusty, warehouse character in the aroma and finish.

Possible sources:

• Age or poor storage of green coffee.
• High ambient humidity around unpacked bags.
• Very slow, drawn-out roasts on already tired coffees.

Adjustments: if Scofi cupping notes are clean and only your roasts taste baggy, look at storage and profile. Faster, more energetic roasts with good airflow can help—but there are limits if green coffee is genuinely aged.

3. Woody / Astringent Cups

Symptoms: drying finish, green wood or cardboard notes, especially as the cup cools.

Possible sources:

• Underdevelopment—too little post-crack time or very fast overall roasts.
• Under-extraction in brewing, especially with coarse grinds.

Adjustments: add 10–20 seconds of development, ensure Maillard is not too short, and check brewing parameters to confirm extraction is in a healthy range.

4. Ashy / Smoky Notes

Symptoms: burnt toast, ashtray or heavy smoke, overpowering origin character.

Possible sources:

• Very dark roast degree or excessive development time.
• Insufficient airflow and dirty roaster surfaces.

Adjustments: lighten the roast slightly, shorten development, increase airflow and ensure your roaster is clean—wet-hulled coffees reveal roaster hygiene issues quickly.

“Wet-hulled Indonesia” covers many regions and flavor profiles. At Scofi, we treat each lot individually, but some broad patterns can help you design starting profiles.

Sumatra (Mandheling, Lintong, etc.)

Often show heavy body, dark chocolate, spice, tobacco and sometimes herbal notes. Roast profiles usually lean toward medium for espresso and medium-light to medium for filter, depending on clarity targets.

Aceh / Gayo Highlands

Gayo coffees can show more sweetness and gentle acidity while still delivering body. With good preparation, you can aim for slightly lighter profiles and use them as single-origin filters as well as blend bases.

Other Wet-Hulled Origins

Wet-hulling appears in parts of Sulawesi, Java and other islands too, often with their own spice and herbal signatures. For each Scofi lot, we provide:

• Region and altitude information.
• Processing details (including hulling and drying notes).
• Cupping descriptors and recommended roles.

Use these as your starting point, then layer on your own cupping results to adjust profiles and menu placement.

Wet-hulled Indonesians can be a signature for your roastery if you approach them systematically. Scofi’s role is to provide consistent green quality and actionable data so you can build repeatable profiles for espresso, filter and blends.

What Scofi Provides

• Green specs: region, altitude, moisture, density, preparation, harvest date and storage notes.
• Cupping data: flavor descriptors, ideal brew methods and recommended menu roles.
• Profile guidance: suggested charge temperature ranges, phase splits and development targets.
• Feedback loop: we welcome your roast logs and cupping feedback to refine future recommendations.

Simple Protocol For New Wet-Hulled Coffees

1. Sample roast using a moderate profile based on Scofi guidance.
2. Cup and decide on primary role: filter, espresso, blend base (or combination).
3. Run 2–3 production test roasts, varying Maillard length and development while keeping charge and charge gas consistent.
4. Cup blind, pick the curve that balances body, sweetness and clarity best.
5. Document gas, airflow and timings so your team can reproduce the profile consistently.

Over time, you’ll build a wet-hulled playbook tailored to your roaster and market, making each new Scofi lot faster to dial in and easier to integrate into your menu.