Natural processing drives whole cherries through weeks of drying with the fruit intact. Microbial fermentation on the cherry skin produces volatile esters — ethyl acetate and related compounds — that migrate into the seed. The result is more body and fruit-forward character than washed coffees from the same beans, with perceived acidity that reads softer because the fermentation chemistry mutes the sharper organic acid profile.
At 1,400 meters, Tiga Raja sits in the mid-range for Indonesian growing altitudes. Altitude explains roughly 25% of variation in extraction yield — at this elevation, the beans are less dense than a 1,900m Sumatran lot, meaning solubles are somewhat less concentrated. Medium roasting is the right call: it pushes through the Maillard reaction fully enough to build body without degrading the fermentation-derived esters that natural processing deposited.
The brown sugar and chocolate notes both trace to Maillard reaction products. Strecker degradation during roasting converts amino acids like valine and leucine into methylpropanal and 3-methylbutanal — compounds that read as malty, chocolate, and dark sugar on the palate. These aren't flavors created by fermentation; they're roast-generated Maillard products that the natural processing's heavier body amplifies in the cup. The orange note comes from citric acid surviving through medium development, brightening the cup without overpowering the heavier fruit-and-chocolate base.
Catimor requires extended roasting time — longer MAI and development phases than most Arabica varieties. Medium development for Catimor means the CGA-to-quinic-acid conversion has run long enough to shed the herbaceous edge that this variety's Robusta parentage introduces while preserving enough caramelization products for the sweetness the brown sugar descriptor promises. The [natural processing](/blog/coffee-processing-methods-explained) adds fruit body on top of that foundation without tipping the cup into the earthy, low-acid territory that Giling Basah — the more common Indonesian method — typically produces.
The Chemex scores 89/100 for Tiga Raja because Catimor's Robusta parentage introduces herbaceous, earthy compounds that paper filtration actively suppresses. The thick Chemex filter strips out the heavier insoluble oils that would amplify these off-character notes in an unfiltered cup, leaving the Maillard-derived brown sugar and chocolate character without the earthy baseline muddying it. Temperature drops to 90°C — a -4°C adjustment accounting for both medium roasting and natural processing — to protect the fermentation aromatics and prevent over-extracting Catimor's Robusta-gene compounds at the later extraction stages. The coarser grind at 590μm reflects Catimor's 1,400m altitude and medium-density bean profile; less surface area is needed because medium roast has higher solubility than light.
Troubleshooting
sour: Grind finer by ~22μm and raise to 91°C. Tiga Raja's 1,400m altitude means medium-density beans — unusual sourness in a medium natural likely indicates the grind is too coarse for full extraction. Don't raise above 91°C without also coarsening the grind, or Catimor's late-extracting herbaceous compounds will emerge.
flat: Grind finer by ~22μm and raise to 92°C. Check bean freshness — Catimor's natural processing adds fruit esters that degrade quickly once ground. If water is very soft, add a small amount of mineral content; the brown sugar and chocolate notes need adequate dissolved minerals to express properly.
The V60 for Tiga Raja operates on a different logic than the same dripper for high-altitude light-roasted African beans. Catimor at medium roast from 1,400m has moderate solubility and medium density — easier to extract than a light-roasted high-altitude SL-28, but still needing paper filtration to manage the Robusta-origin herbaceous character that Catimor's Catimor-group ancestry (Timor Hybrid x Caturra) can contribute. At 540μm, the grind is noticeably coarser than light-roast recommendations because medium roast has higher solubility and the lower-altitude bean generates fewer problematic fines. The 90°C temperature protects the natural processing's fermentation esters — the orange note that persists at medium development — from thermal degradation during the 2:30-3:30 brew window.
Troubleshooting
sour: Grind finer by ~22μm and raise to 91°C. Unlike light-roast beans in this batch, Tiga Raja's medium roast should extract cleanly — sourness here usually means the 540μm grind has drifted too coarse or the water temperature has dropped significantly below 90°C by mid-pour. Check kettle temperature consistency.
flat: Grind finer by ~22μm and raise to 92°C. Flat extraction in a medium natural usually signals either old beans or very soft water. Catimor's brown sugar and chocolate notes require adequate extraction depth — a flat cup means Maillard compounds aren't dissolving, not that the bean lacks them.
The Kalita Wave's flat-bed extraction is a good match for Tiga Raja because Catimor produces a more uniform particle distribution than Ethiopian heirloom varieties, and the flat bed's water distribution advantage is most useful when fines aren't dominating the bed. At 570μm on a flat bed, water contacts the entire surface evenly, extracting the brown sugar and chocolate character from Maillard and Strecker reactions — without creating the fast-channel zones that would skip over natural processing's fermentation-deposited esters. Temperature at 90°C is -4°C below the altitude ceiling, accounting for natural processing and medium roast together. The 3:00-4:00 window gives Catimor's extended-roasting-requirement variety enough contact time without pushing into the herbaceous zone that over-extraction would reveal.
Troubleshooting
sour: Grind finer by ~22μm and raise to 91°C. Sourness in Tiga Raja on the Kalita is less likely than in the lighter beans in this batch — if it appears, suspect the grind setting drifted or the water temperature dropped below 88°C. Don't pour on filter walls; keep pours central to maintain even bed saturation.
flat: Grind finer by ~22μm and raise to 92°C. The Kalita's even extraction should prevent flat cups from uneven flow, but Catimor can taste muted if extraction stops short. Check bean age — the natural processing's volatile esters degrade faster than washed coffee solubles and diminish within 3-4 weeks of roast.
The AeroPress presents a different challenge for Tiga Raja: the troubleshooting shifts from sour (the dominant failure mode for light-natural beans) to strong and bitter. This is a direct consequence of medium roasting and lower altitude. Catimor at 1,400m and medium roast has meaningfully higher solubility than high-altitude light-roasted beans — the AeroPress's concentrated 1:12-1:13 ratio and fine 440μm grind can over-extract rather than under-extract. Temperature drops to 81°C, the lowest effective temperature among the nine brewers, protecting against both over-extraction of Catimor's late-stage Robusta compounds and over-concentration of the already-concentrated espresso-style AeroPress ratio. The short 1:00-2:00 steep limits contact time as an additional over-extraction safeguard.
Troubleshooting
strong: Reduce dose by 1g or add 15g water. The AeroPress concentrates Tiga Raja's readily-soluble medium-roast solubles quickly — at 81°C and 440μm, over-strength is the primary risk rather than underextraction. Extend the ratio toward 1:13.5 before adjusting grind.
bitter: Grind coarser by ~22μm and drop to 80°C. Catimor's Robusta lineage means its late-extracting compounds have more herbaceous and earthy character than pure Arabica varieties. Bitterness in Tiga Raja AeroPress indicates over-extraction into those Robusta-gene dry distillates — coarser grind and lower temperature both reduce their extraction rate.
The Clever Dripper's immersion phase works well for Tiga Raja because the 3:00-4:00 steep at 90°C with a 570μm grind lets extraction proceed at a controlled rate, drawing out the brown sugar Maillard compounds and natural-process orange note without the turbulence of continuous pouring. Catimor typically requires a longer development phase during roasting to suppress its Robusta-parentage herbaceousness — that extended roasting creates a medium-roast bean with higher solubility than most light roasts, meaning the Clever Dripper's gentler extraction dynamics don't need temperature or grind compensation beyond the standard medium-natural adjustments. Paper filtration resolves the natural-process oils, and the immersion time is long enough for the orange note — bright acidity that persists through medium development — to fully extract before drawdown.
Troubleshooting
strong: Reduce dose by 1g or add 15g water. The Clever Dripper's full immersion combined with Catimor's medium-roast solubility can push TDS above target at 18g/288g. Reduce dose first; the brown sugar and chocolate notes dilute more gracefully than they concentrate.
bitter: Grind coarser by ~22μm and drop to 89°C. Bitterness in Tiga Raja on the Clever Dripper is specifically a Catimor warning — the Robusta-lineage late-extraction compounds are bitter and earthy. Shortening steep time by 20-30 seconds is the fastest fix if bitterness appears mid-session.
Tiga Raja at 77/100 for espresso is a meaningfully better match than most light-natural beans at espresso. Medium roasting gives Catimor higher solubility; 1,400m altitude means medium rather than very-high bean density. The machine can extract this bean efficiently within the 0:25-0:30 window without the extended ratios needed for light-roasted high-altitude coffees. Temperature at 89°C — the -4°C full adjustment for medium-roast plus natural processing — keeps Catimor's Robusta-gene late-extraction compounds from entering the shot at the aggressive rates that higher temperatures would cause. The ratio (1:1.5-2.5, centered around 1:2) is slightly shorter than a light-natural espresso recipe because medium roast doesn't need the extended pull to achieve adequate yield. Expect brown sugar-forward shots with chocolate depth and citrus brightness from the orange note.
Troubleshooting
strong: Reduce dose by 1g or extend to a longer ratio — 1:2.5 or beyond. Catimor's higher solubility at medium roast can push TDS above target quickly. Pulling a longer shot also moves the flavor profile toward the chocolate notes and away from the potentially heavy-bodied concentration of a short pull.
sour: Grind finer by ~10μm and raise to 90°C. Sourness in Tiga Raja espresso indicates the 290μm grind hasn't created enough resistance for a full extraction within 25-30 seconds. A 10μm finer adjustment at espresso scale is significant — test in small increments.
The Moka Pot is a substantially better fit for Tiga Raja (68/100) than it would be for light-natural beans because medium roasting raises solubility to a level where the moka pot's 1.5 bar steam pressure can extract adequately. At 1,400m altitude, medium density also reduces the extraction barrier compared to very-high-density beans grown at 2,100-2,200m. The 390μm grind — medium-fine, not espresso-fine — is the appropriate moka pot target for a bean this soluble; going finer risks over-extraction into Catimor's herbaceous Robusta compounds. Temperature reaches 96°C effective here, and pre-boiling the base water is especially important for a medium-roast natural with fruit aromatics that degrade under prolonged heat before pressure builds.
Troubleshooting
strong: Reduce dose by 1g or add 15g to the base water. The moka pot's 1:9.5-1:10.5 ratio is inherently concentrated, and Catimor at medium roast extracts more readily than the light-natural beans. Remove from heat promptly at first sign of sputtering — Tiga Raja over-extracts faster than a light roast would.
sour: Grind finer by ~22μm and use pre-boiled water. Sourness in a medium natural moka pot is unusual but indicates the grind is too coarse — easy to drift given Catimor's medium-fine sweet spot. Pre-boiling eliminates the cold-water heating phase that reduces effective extraction temperature.
French Press at 66/100 for Tiga Raja works better than for the light naturals because medium roast + natural processing + Catimor's more accessible solubility all favor the immersion approach. The metal mesh will pass natural-process oils, which for this bean means body amplification from the fermentation-deposited esters — adding weight to the brown sugar and chocolate profile rather than muddying a delicate fruit character. At 1,040μm, the grind is coarser than standard French Press recommendations to account for the full 4:00-8:00 steep window; Catimor at medium roast would over-extract at a standard coarse grind in extended immersion. Temperature at 92°C is -4°C below boiling — the medium-roast and natural-process adjustments both pull temperature down, and the French Press's retained heat makes this sustainable throughout the steep.
Troubleshooting
strong: Reduce dose by 1g or add 15g water. French Press immersion combined with Catimor's medium-roast solubility can push TDS higher than the 1:14.5-1:15.5 ratio suggests. Don't extend steep time to compensate for a previous under-dose — that risks extracting Catimor's herbaceous late compounds.
bitter: Grind coarser by ~22μm and drop to 91°C. Bitterness in Tiga Raja French Press specifically indicates extraction into Catimor's Robusta-lineage dry distillates — herbaceous, earthy bitterness rather than the clean bitter of dark chocolate. Shorten steep by 1 minute and coarsen grind together for the fastest correction.
Cold Brew at 64/100 is the best-scoring non-paper-pour-over for Tiga Raja — and a legitimate method choice, not just a fallback. Medium roasting makes Catimor's solubles more accessible in cold water than a light roast would be; the brown sugar, chocolate, and orange notes are all Maillard-derived or citric-acid based, neither of which requires high temperature for dissolution the way volatile fermentation esters do. The metal mesh passes the natural-process oils into the concentrate, adding body that cold brew from this medium-density 1,400m bean would otherwise lack. At 940μm and 12-18 hours, the extraction kinetics are slow but adequate — science shows caffeine and chlorogenic acids plateau around 6-7 hours, but Maillard-derived melanoidins that produce body and chocolate character continue extracting slowly through the full 12-18 hour window.
Troubleshooting
flat: Grind finer by ~22μm and check bean freshness. A flat Tiga Raja cold brew means the Maillard compounds — the primary flavor drivers — aren't dissolving adequately. Catimor's natural processing esters are volatile and degrade faster than washed coffee solubles; confirm the beans are within 4 weeks of roast.
strong: Reduce dose by 1g or add 15g water to the concentrate. Cold brew from a medium natural is more concentrated than cold brew from a light roast because medium roast solubles dissolve more readily in cold water. At 80g/560g, even a small dose increase significantly raises the finished concentrate TDS.