Onyx Coffee Lab

Peru San Martin de Pangoa

peru light roast washed bourbon, typica

cherryyellow pearwhite teacaramel

Junín sits in Peru's central jungle highlands, where the Andes meet the Amazon basin — a growing environment that differs from Cajamarca's drier northern highlands. The humidity, cloud cover, and rainfall patterns in Satipo Province affect cherry development in ways altitude alone doesn't capture. At 1,900 meters, maturation is slow but not extreme, producing a balanced soluble load rather than the maximum-density extraction potential of a 2,300+ meter lot. Cherry and yellow pear in a washed coffee map to specific acids. Cherry is citric acid — it's the only organic acid in brewed coffee that consistently exceeds its sensory detection threshold, which is why it reads so clearly as a distinct flavor note rather than background brightness. Yellow pear is malic acid's territory: crisp, slightly sweet, stone-fruit adjacent. These are the first compounds extracted during brewing — the fast-dissolving acids that lead the cup before Maillard and caramel compounds arrive. White tea character is the distinctive note. In Bourbon and Typica — both classic Bourbon-Typica lineage varieties — at light roast and high chlorogenic acid levels, phenolic compounds produce an astringency too light to read as bitter but present enough to feel tea-like. That thin mouthfeel is a low melanoidin signature: light roasting produces intermediate molecular weight melanoidins, which give body without weight. The result reads as delicate rather than watery. Caramel completes the picture: the caramelization products that form just after first crack are the aroma-mediated sweetness mechanism. The sucrose is gone — nearly 100% consumed by roasting — but furanones and maltol trigger the brain's sweet perception through retronasal olfaction.

Chemex 6-Cup 96/100

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

The Chemex earns the top match score here because its thick paper filter does exactly what this Peru San Martin needs: it strips the insoluble oils that would muddy the white tea character and lets the delicate pear character note come through without interference. The grind is dialed 40μm finer than Chemex default to compensate for the light roast's reduced solubility — Bourbon and Typica at light development yield fewer solubles into solution, and the coarser default would leave the cherry and caramel notes underextracted. The slightly leaner ratio (1:15-1:16 vs. standard) keeps TDS in range despite the longer 3:30-4:30 drawdown the thick paper enforces. The result is a cup where the cherry brightness leads, the malic pear sweetens the mid-palate, and the white tea finish is the phenolic character the filter didn't strip.

Troubleshooting

sour: Grind finer by ~22μm and raise temp 1°C. At light roast, Bourbon and Typica solubles dissolve slowly — the cherry and caramel are still locked in if extraction stops early. Finer grind adds surface area so those flavor compounds reach the cup before drawdown ends.

thin: Add 1g dose or remove 15g water. This Peru's light roast and 1,900m density mean it contributes fewer total solubles per gram than a darker or lower-altitude bean. If the cup reads watery rather than tea-like delicate, you're understrength — not underextracted.

Hario V60-02 88/100

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

The V60 lands at 88/100 for this Peru because it rewards controlled pours that manage extraction evenness — the exact challenge a light-roasted Bourbon/Typica presents. Both varieties sit in the Bourbon-Typica group with medium-density beans at 1,900m; the 460μm grind (40μm finer than standard) compensates for the reduced solubility at light roast. V60's single-walled cone and open drain hole mean flow rate tracks directly with your grind — if the cherry reads flat or the white tea finish disappears, the bed is draining too fast. The 94°C water and 1:15-1:16 ratio are calibrated to extract the caramel and pear notes in the mid-extraction window before the short brew time closes. Swirling at the bloom is important here: Bourbon's moderate fines load benefits from early agitation to wet the bed evenly.

Troubleshooting

sour: Grind finer by ~22μm and bump temp to 95°C. The yellow pear and cherry notes in this Peru are early-extracting acids — if the bed drains before Maillard compounds follow, you'll get brightness without the caramel sweetness that should balance it.

thin: Add 1g dose or reduce water by 15g. Light roast Peru at 1,900m has moderate soluble density — not low enough to be truly difficult, but enough that a slightly lean ratio will read thin rather than clean. More coffee closes that gap.

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 geometry and three-hole drain distribute flow across the entire bed rather than funneling it through a central cone — this matters for the Peru San Martin because it reduces the channeling risk that a light-roasted, medium-density bean presents. The 490μm grind (40μm finer than Kalita default) and 94°C water keep extraction on track despite light roast's lower solubility. The 1:16-1:17 ratio is slightly leaner than the Chemex or V60 targets, reflecting the Kalita's less aggressive filter material and somewhat lower TDS output. Bourbon and Typica at this altitude produce a clean, balanced extraction when the bed is evenly saturated — the Wave's flat bottom does most of that work structurally. The cherry and pear should arrive with equal intensity rather than the citric-dominant profile you'd get from an uneven pour.

Troubleshooting

sour: Grind finer by ~22μm and raise temp 1°C. With the Kalita's flat bed, uneven wetting is less of a factor — sourness here is almost always grind-related underextraction of this light-roasted Peru's caramel and pear compounds. Finer grind solves it.

thin: Add 1g dose or reduce water by 15g. The 1:16-1:17 ratio runs lean by design to keep the Kalita's lower extraction efficiency in range. If the cup lacks presence, tighten the ratio first before adjusting grind.

AeroPress 82/100

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

The AeroPress scores 82/100 and is a good choice for someone who wants this Peru's cherry and white tea character in a shorter, more concentrated format. The 360μm grind — 40μm finer than standard — compensates for the light roast's reduced solubility within the compressed brew window, and the pressure during the plunge assists extraction efficiently. The 1:12-1:13 ratio produces a concentrated cup, and the AeroPress's immersion format keeps the the bright acids balanced alongside the caramel sweetness rather than letting the acids run ahead. The 1:00-2:00 brew window is wide enough to capture those sweet compounds that follow the initial acid extraction — aim for the longer end if the cup reads tart, shorter end if it reads flat.

Troubleshooting

sour: Grind finer by ~22μm and raise temp 1°C. At 85°C with a short brew window, this light-roasted Peru's caramel and pear notes extract slowly. More surface area via finer grind moves the flavor window faster within the same contact time.

thin: Add 1g or reduce water 15g. The 1:12 ratio is already stronger than filter methods, but light roast Bourbon and Typica yield fewer dissolved solids than darker roasts of the same variety. Tighten the ratio if the cup lacks 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 sits at 82/100 by combining immersion contact time with paper filtration — the immersion phase helps this light-roasted Peru's lower-solubility Bourbon and Typica varieties extract more evenly than a free-draining pour-over, while the paper removes the oils that would weigh down the white tea character. The 490μm grind and 94°C water match the Kalita Wave parameters because both brewers target a similar bed resistance. The 1:15-1:16 ratio produces a slightly richer cup than V60, appropriate for the immersion boost. The 3:00-4:00 steep window is the extraction sweet spot: enough contact time for caramel and pear to follow the initial cherry extraction, short enough to avoid bitter compounds pickup at the slow tail of extraction. Release the valve at 3 minutes, then let it drain without agitation.

Troubleshooting

sour: Grind finer by ~22μm and raise temp 1°C. The Clever's immersion phase front-loads extraction — sourness means the caramel and white tea compounds didn't follow the cherry acids into solution. Finer grind in immersion mode speeds extraction without changing steep time.

thin: Add 1g dose or reduce water 15g. If the cup reads clean but insubstantial, the immersion boost wasn't enough to compensate for the light roast's lower soluble yield. More coffee solves this faster than extending steep time.

Espresso 81/100

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

Light-roast espresso with this Peru's Bourbon and Typica at 1,900m presents as a dense, less-soluble puck that standard espresso parameters will underextract. The 210μm grind (40μm finer than standard light-roast espresso), 93°C water, and extended 1:1.9-2.9 output ratio all pull in the same direction: more extraction through a dense, high-altitude coffee that resists dissolving under pressure. The cherry and caramel notes will be amplified by pressure extraction but can easily tip into sharp citric sourness if the puck channels — preinfusion at low pressure for 5-8 seconds before ramping to full pressure is strongly recommended. The 1:2.9 end of the ratio range will produce the most balanced result; shorter ratios at light roast emphasize acidity.

Troubleshooting

sour: Grind finer by ~10μm and raise temp 1°C. Light-roast espresso sourness at this ratio usually means channeling before extraction is complete. Go finer in small increments — 10μm at a time — and add preinfusion if your machine allows it.

thin: Add 1g dose or reduce output by 15g. At 1:2.9, this Peru should be concentrated enough to carry intensity — if it reads thin, you're either channeling early or the ratio is too long. Pull shorter before adding more dose.

Moka Pot 79/100

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

The Moka Pot at 79/100 is a workable but compromised brewer for this Peru. The 310μm grind is medium-fine — coarser than espresso but finer than AeroPress — balancing flow rate against the ~1.5 bar pressure the Moka generates. At 100°C base water (use pre-boiled water per Hoffmann's method to avoid cooking the grounds during heat-up), the light-roasted Bourbon and Typica will extract at the upper end of their range. The cherry note will read as the dominant acid given the concentration; the delicate white tea character tends to disappear in the Moka's unfiltered, oil-forward environment. The 1:9-1:10 ratio produces a concentrated beverage — sip it short or dilute with hot water if the cherry becomes too intense. Remove from heat when sputtering begins.

Troubleshooting

sour: Grind finer by ~22μm and ensure pre-boiled water. Moka sourness in a light roast is almost always under-extraction at the grind — the coarser particles can't release caramel and Maillard compounds fast enough at 1.5 bar before the boiler runs dry.

thin: Add 1g dose or reduce base water by 15g. The Moka basket should be full — a partial fill produces a weaker extraction. For this light-roasted Peru, filling the basket completely and adjusting the base water is more effective than changing grind.

strong: Reduce dose by 1g or add 15g base water. Moka concentrations at 1:9-1:10 are already intense. If the cherry becomes harsh rather than bright, dilute with hot water after brewing rather than changing grind, to avoid slowing flow.

French Press 76/100

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

The French Press scores 76/100 for this Peru — lower than the filter methods because full immersion with metal filtration creates tension between this bean's strengths and this method's mechanics. The white tea character becomes heavier in French Press because oils pass through the metal filter and add body the bean isn't designed to carry. The 960μm grind and 96°C water at 1:14-1:15 ratio are calibrated to maximize extraction from the coarse bed before the extended steep extracts too many dry-distillate compounds. The 4:00-8:00 window is broad — start tasting at 4 minutes, pull before 6 if the cherry is reading clean, extend toward 8 only if it reads sour. Letting grounds settle before pouring (Hoffmann method) will improve clarity significantly.

Troubleshooting

sour: Grind finer by ~22μm and raise temp 1°C. French Press extracts from a coarse bed over time — if the cherry is sharp and pear is absent, the steep ended before the Maillard and caramel compounds dissolved. More surface area accelerates extraction without shortening steep time.

thin: Add 1g dose or reduce water 15g. Light-roasted Bourbon and Typica at this altitude don't over-extract easily in French Press — if the cup reads thin, you're understrength. More coffee is the fix; don't extend steep time first.

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.