Market Lane Coffee

Laurence Mukakabera

rwanda light roast washed bourbon

cherryorangestonefruit

Northern Province Rwanda at 1,980 meters is close to the altitude ceiling where Rwandan specialty grows before diminishing returns set in. The research quality sweet spot for equatorial arabica sits between 1,400 and 1,900 meters — this lot runs just above that band, and the chemistry shows it. Cherry, orange, and stonefruit describe a profile built on citric and malic acids working in close balance. Citric is the primary acid — the only organic acid in coffee that consistently exceeds its sensory detection threshold in brewed coffee — and at light roast pH around 4.85 to 5.10, it reads bright and clean in the cherry and orange register. Malic acid adds the stone-fruit backbone: apricot-adjacent, crisp, slightly sweet. The two together create the tart-but-sweet layering that makes high-altitude washed Rwandan Bourbon distinct from lower-grown or darker-roasted lots. Washing through tank fermentation at Kinyonzo-Gihura removes the fruit mucilage, stripping away fermentation variables and letting altitude and Bourbon genetics drive the cup. Bourbon-group cultivars roast as high-density beans — they need more energy and longer time to reach first crack — and that density is why 1,980m Bourbon carries more concentrated solubles than lower-altitude origins. Light roasting preserves the acid structure that altitude built. Chlorogenic acids remain largely intact, maintaining brightness and keeping quinic acid accumulation low — quinic is the harsh, bitter acid that builds when CGAs decompose, either during darker roasting or in old coffee sitting on a burner. Keeping development short stops that decomposition pathway before it takes hold. For extraction, 1,980m washed Bourbon extracts predictably and at the higher end of yield potential. Grind evenness determines whether the cherry and orange notes express cleanly or get muddied by simultaneous over- and underextracted particles.

Chemex 6-Cup 96/100

Grind: 510μm Temp: 94°C Ratio: 1:15.0-1:16.0 Time: 3:30-4:30

The 96/100 match here reflects a genuine alignment between what the Chemex does and what 1,980m washed Bourbon needs. The 20-30% thicker Chemex paper traps all cafestol and oils, leaving only the water-soluble compounds — and for a bean whose character is built on citric and malic acid clarity, that filter action is a feature, not a loss. The grind at 510μm is 40μm finer than the default, compensating for light roast's lower solubility — light roasts retain more chlorogenic acid intact, which means you need more surface area exposure to push extraction into the 18-22% range where cherry and orange register as sweetness rather than just sourness. The ratio at 1:15.5 is slightly stronger than standard to offset the extended drawdown the thick filter causes, keeping TDS in the sweet spot without over-running brew time.

Troubleshooting

sour: Grind 22μm finer and raise temp 1°C. At 1,980m, the Bourbon's chlorogenic acid load is high from light roasting — sourness here means the citric and malic acids extracted while caramelization compounds lagged. Finer grind increases surface area to drive the extraction curve past the acid-dominant phase.

thin: Add 1g more coffee or remove 15g water. The Chemex's thick filter and slow drawdown can produce low TDS from this light washed Bourbon, especially if the grind is slightly coarse. More dose immediately raises dissolved solids without altering the extraction chemistry.

Hario V60-02 88/100

Grind: 460μm Temp: 94°C Ratio: 1:15.0-1:16.0 Time: 2:30-3:30

The V60's ribbed walls and single bottom hole create relatively fast, unrestricted flow — which suits this 1,980m washed Bourbon well because high-density light-roasted beans resist extraction and benefit from controlled turbulence during the pour rather than long immersion. The 460μm grind, 40μm finer than default, is the key adjustment for light roast: it increases the surface area available for water contact, counteracting the lower solubility caused by extraction-resistant light-roast structure that haven't been degraded by darker roasting. At 94°C, you're high enough in the 195-205°F ideal range to maximize diffusion into these dense Bourbon cells without tipping into bitter compound extraction. The 1:15.5 ratio aligns with the Chemex but the faster V60 drawdown means the brew finishes cleaner, slightly less filtered than Chemex — still crisp cherry-orange character but with marginally more texture.

Troubleshooting

sour: Grind 22μm finer and raise temp 1°C. The 1,980m Bourbon's light roast leaves CGAs largely intact — when sourness dominates, the extraction stopped in the fast-dissolving acid phase. Finer grind extends contact time and surface area to pull the caramelization compounds through.

thin: Add 1g dose or reduce water by 15g. Light roast washed Bourbon at this altitude extracts efficiently but TDS can undershoot when grind is too coarse or pour is too fast. A metal filter would also add body by allowing micro-fines and oils through.

Kalita Wave 185 88/100

Grind: 490μm Temp: 94°C Ratio: 1:16.0-1:17.0 Time: 3:00-4:00

The Kalita Wave's flat-bottom design and three small holes create more even flow across the entire bed compared to the V60's single-hole cone — this matters for a bean like the Laurence Mukakabera because extraction evenness is the controlling variable. If some particles overextract while others underextract, cherry and orange smear into a muddy, simultaneously sour-and-bitter cup even when average EY looks correct. The flat bed distributes water contact more uniformly, reducing channeling. The grind at 490μm sits 40μm finer than default for the same light-roast solubility reasons, and the 1:16.5 ratio is slightly leaner than the Chemex and V60 settings — the Kalita's moderate flow rate means slightly longer contact time per gram of water, so you can run a bit thinner ratio without losing extraction yield. The result is a balanced, well-extracted cup that foregrounds the stone-fruit malic acid character.

Troubleshooting

sour: Grind 22μm finer and raise temp 1°C. Sourness in the Kalita points to the light roast Bourbon's acid-dominant early extraction phase dominating — the flat bed's even flow helps, but if grind is too coarse the caramelization compounds don't dissolve fully, leaving cherry and orange as tart rather than sweet-bright.

thin: Add 1g dose or reduce water by 15g. The Kalita's moderate flow rate can produce adequate extraction but low TDS if dose is light. More coffee or a metal filter substitute increases dissolved solids and adds the textural weight that washed high-altitude Bourbon can carry.

AeroPress 82/100

Grind: 360μm Temp: 85°C Ratio: 1:12.0-1:13.0 Time: 1:00-2:00

The AeroPress brews this washed Rwandan Bourbon at 85°C with a 360μm grind — 40μm finer than standard to account for the light roast's density. The fine grind and the pressure assist during pressing work together to maintain adequate extraction in the 1-2 minute brew window. The AeroPress format naturally keeps bitter compound extraction in check, since bitter compounds and polyphenols dissolve more readily at higher temperatures — so the grind fineness drives yield while the cup stays clean, letting you pull the cherry and stonefruit compounds without triggering bitterness. The 1:12.5 ratio is concentrated — this is designed as a short, intense cup. The Bourbon's malic acid character reads quite clearly at this concentration, and the pressure-assisted finish adds a touch of body that pure gravity filtration doesn't produce.

Troubleshooting

sour: Grind 22μm finer and raise temp 1°C. At 85°C, the light washed Bourbon is on the edge of adequate extraction — sourness here means the temperature-extraction balance tipped toward underextraction. Finer grind compensates without requiring higher heat that could introduce bitterness.

thin: Add 1g dose or reduce water by 15g. At the AeroPress's 1:12.5 ratio this bean should produce good TDS, but if grind is too coarse or press is too fast, solubles don't fully dissolve. A metal AeroPress filter also allows fines and oils through for more body.

Clever Dripper 82/100

Grind: 490μm Temp: 94°C Ratio: 1:15.0-1:16.0 Time: 3:00-4:00

The Clever Dripper combines immersion steeping with a paper filter drain — a hybrid that changes the extraction dynamic compared to pure pour-overs. During the 3-4 minute steep, all the grounds sit in contact with all the water simultaneously, which means this light roast Bourbon gets more uniform initial wetting than a pour-over where water cascades progressively through the bed. That full-bed immersion phase is an advantage for high-density 1,980m Bourbon: every particle gets the same temperature exposure and the same contact time before the valve opens. The 490μm grind at 40μm finer than default reflects the same light roast solubility adjustment applied across methods. The paper filter drains cleanly, so the cherry and orange acidity comes through without metallic micro-fines that would muddy the brightness. The result sits between the V60's clarity and the French Press's immersion texture.

Troubleshooting

sour: Grind 22μm finer and raise temp 1°C. The Clever's immersion phase helps even extraction, but with a high-density light roast Bourbon, sourness indicates the steep time or grind wasn't sufficient to move past the acid-extraction phase into the caramelization compound zone.

thin: Add 1g dose or reduce water by 15g. The Clever's paper filter removes oils and fines, which can produce a cleaner but lighter cup from this light-roasted washed bean. More dose directly addresses TDS without requiring grind changes.

Espresso 81/100

Grind: 210μm Temp: 93°C Ratio: 1:1.9-1:2.9 Time: 0:28-0:35

Light roast washed Bourbon at 81/100 for espresso is a valid but demanding match. Light-roast espresso is challenging here because 1,980m Bourbon's light roast means low solubility, high density, and the dense, extraction-resistant structure of light roasting — pressure alone doesn't solve these; they require a finer grind (210μm, the minimum in the range), a longer ratio (1:2.4, not a ristretto), and ideally a preinfusion phase to wet the puck before full pressure engages. The 93°C temperature is slightly below the pour-over default to moderate bitter compound extraction under 9-bar pressure, where extraction rates are dramatically higher than gravity methods. The longer ratio dilutes the concentrated intensity of pressure extraction while still driving enough yield to dissolve the caramelization compounds behind cherry and stonefruit. Expect bright, fruit-forward shots — this is not a chocolate-and-body espresso.

Troubleshooting

sour: Grind 10μm finer and raise temp 1°C. Sour espresso from light washed Bourbon means the puck resistance is too low — water channeled through without sufficient extraction. Smaller grind adjustment (10μm vs 22μm for pour-overs) because espresso is already near the lower grind limit and pressure amplifies extraction changes.

thin: Add 1g dose or reduce yield water by 15g. Thin espresso here means TDS is below the 8-12% target. Light roast Bourbon resists extraction at 9 bar — more dose in the puck increases resistance and solubles simultaneously, pushing shots into the correct concentration range.

Moka Pot 79/100

Grind: 310μm Temp: 100°C Ratio: 1:9.0-1:10.0 Time: 4:00-5:00

The moka pot runs at approximately 1.5 bar — far below espresso's 9 bar but above atmospheric pressure — and that limited pressure advantage affects how this light roast Bourbon extracts. The 310μm grind is finer than pour-over targets but coarser than espresso: fine enough to slow the steam-forced water through the bed for adequate contact time, but not so fine that the small basket overpressurizes and channels. Using pre-boiled water in the base (not cold) is critical here — cold water allows ground heating from below, which extends extraction time unevenly and over-extracts bitter compounds before the brew completes. At 79/100, this is a workable match: the cherry and orange notes survive the pressure extraction, but the concentrated ratio at 1:9.5 means this bean's bright acidity reads intense and sharp. The 40μm finer grind adjustment accounts for light roast density.

Troubleshooting

sour: Grind 22μm finer and raise temp 1°C. In the moka pot, sourness from this washed light Bourbon often means flow was too fast through the basket — water passed without sufficient extraction. Finer grind slows flow and increases contact surface, pushing past the acid-dominant extraction phase.

thin: Add 1g dose or reduce water by 15g. Thin moka pot output with this bean usually means the basket wasn't fully packed or dose was light. Fill the basket to the rim without tamping — the moka pot is designed for full basket use and TDS drops significantly with partial fills.

strong: Reduce dose 1g or add 15g water. At 1:9.5, this moka pot recipe is already concentrated. If output is too intense, a slightly leaner ratio or a small amount of hot water to dilute the finished cup is the quickest fix without disrupting the basket setup.

French Press 76/100

Grind: 960μm Temp: 96°C Ratio: 1:14.0-1:15.0 Time: 4:00-8:00

The French Press is the lowest-scoring hot brew method at 76/100, and the mechanism is clear: metal mesh filtration passes oils and micro-fines into the cup, and washed light Bourbon's flavor identity is built on the clean acid brightness that paper filtration protects. The 960μm grind is noticeably coarser than the pour-over settings — this is essential for French Press because fine grinds clog the metal mesh and allow excessive sediment through, plus they overextract during the 4-8 minute steep. Coarser particles extend adequately over longer immersion time, and the light roast's low solubility is compensated by the extended steep rather than a finer grind. At 96°C (2°C higher than the pour-over methods), the higher temperature drives diffusion in the open, unfiltered steep environment. The cherry and orange are present but the metal mesh allows oils through, softening the acid clarity that makes this bean interesting.

Troubleshooting

sour: Grind 22μm finer and raise temp 1°C. For this light washed Bourbon in a French Press, sourness means the coarse grind and/or insufficient temp didn't reach the caramelization compounds during the steep. Slightly finer grind increases surface area — but don't go too far or sediment increases sharply.

thin: Add 1g dose or reduce water by 15g. Light roast beans extract fewer solubles per gram at French Press temperatures than medium or dark roasts. If the cup tastes watery, more dose is the lever — coarser grind for French Press leaves less surface area, so dose is the primary TDS control.

Cold Brew Flash Brew Recommended

Cold brew is not recommended for this bean. At near-freezing temperatures, cold water cannot extract the complex acids, delicate aromatics, and bright fruit compounds that define a light-roasted coffee — they remain locked in the cell matrix. For a cold version of this coffee, use flash brew: brew a concentrated pour-over (V60 or Chemex at 60% of the normal water volume) directly over ice in the server. The hot water extracts the full flavor spectrum, and the rapid ice cooling locks in volatiles that would otherwise evaporate during a slow cool-down.