Marsellesa is not a common variety in specialty coffee bags from Peru. Developed by CIRAD and Ecom, it's a Sarchimor-group variety — derived from Timor Hybrid crossed with Villa Sarchi — classified as highly resistant to coffee leaf rust with very high yield. What it brings to a cup alongside Bourbon is a disease-resilient variety with Robusta introgression that, at medium-light roast, integrates differently than at light roast.
The extra development in medium-light roasting matters here. Light roasting preserves volatile acids and aromatic compounds but can leave phenolic sharpness in varieties with Robusta genetics. Medium-light pushes further into Maillard development — more melanoidin formation for body, more caramelization for warmth — while stopping before the heavier dry-distillate compounds dominate. For Marsellesa, this is the right balance: the Robusta-adjacent genetics contribute earthiness at light roast, but medium-light roasting replaces that with the pecan and brown sugar character listed in the tasting notes.
Blackcurrant is the highest-note deviation from Peru's typical mild profile. That deep, wine-forward berry character traces to higher chlorogenic acid levels interacting with citric acid at medium-light roast: some CLAs survive, some convert to quinic acid, and the interplay between those compounds at this roast level produces a more complex, darker fruit profile than lighter roasts give.
Bourbon contributes its characteristic sweet complexity — a 20–30% yield increase over Typica and a delicate, crisp acid structure that balances Marsellesa's more assertive character. At 1,775 meters, just below the Peruvian median altitude, the soluble load is calibrated for medium-light development rather than fighting against it.
The V60's conical bed and single drain hole mean flow rate is largely governed by grind size — and this Bourbon-Marsellesa blend from 1,775m Peru requires careful calibration. The recipe pulls grind to 490μm, reflecting the modest roast and variety adjustments. Temperature lands at 93°C rather than the default 94°C — medium-light roast means slightly more developed melanoidins and better solubility than light roast, so slightly cooler water prevents the blackcurrant acidity from tipping toward harsh. The 1:15.3–1:16.3 ratio, pushed 0.5 above default, compensates for the modest soluble load typical of Peru's 1,775m growing altitude, which concentrates sugars and acids but not as aggressively as higher-grown lots.
Troubleshooting
sour: Grind finer by ~22μm and raise temp by 1°C. With Marsellesa's denser bean structure, underextraction stops before caramelization compounds dissolve — leaving blackcurrant acidity unbalanced and thin. Finer grind increases surface area so extraction reaches the brown-sugar sweetness hiding underneath the acid layer.
thin: Add 1g dose or reduce water by 15g. Peru at 1,775m builds moderate soluble density — if TDS is low, the pecan and brown sugar notes won't register. A metal filter can also help recover body that the V60 paper is stripping from the Marsellesa's oils.
The Kalita Wave's flat-bottom bed with three small drain holes produces the most even saturation of any pour-over dripper — a genuine advantage for this Bourbon-Marsellesa blend where particle size variation across two variety types could cause channeling in a conical dripper. Grind at 520μm, slightly finer than the Chemex and close to the V60 setting, because the flat bed's shorter water path means less contact time per unit of grind coarseness. At 93°C, the medium-light roast's melanoidin body is preserved while keeping the well-developed Maillard compounds — the pecan character and brown sugar warmth — from extracting into harshness. The Kalita is the most forgiving choice for this bean precisely because the flat bed prevents the flow-rate variability that mixed-variety lots can cause in conical designs.
Troubleshooting
sour: Grind finer by ~22μm and raise temp by 1°C. Flat-bed Kalita extraction is even, but if the bed passes water too quickly, finer grind compensates by increasing puck resistance and extending extraction into the sweet compounds.
thin: Add 1g dose or reduce water by 15g. The Kalita Wave's paper filter removes oils effectively — for this Peru medium-light, TDS can run lean if the grind is even slightly coarser than optimal. A metal filter is also worth testing to recover the Bourbon variety's characteristic body.
The Chemex's 20–30% thicker bonded paper filter is the most aggressive oil-stripping filter available, which creates a specific tension with this Bourbon-Marsellesa blend. Marsellesa carries mild Robusta-lineage earthiness that, at medium-light roast, has already been largely replaced by pecan and caramel character — but any residual oils amplifying that earthiness will be stripped here. The result is a cup that foregrounds the blackcurrant brightness and brown sugar sweetness with exceptional clarity. Grind at 540μm — coarser than the V60 setting — to compensate for the Chemex filter's slower flow and avoid over-extraction of the Maillard compounds the medium-light development produced. The 93°C temperature preserves the delicate top notes without pushing the CGA-derived bitterness that medium-light roast still retains.
Troubleshooting
sour: Grind finer by ~22μm and increase temp by 1°C. The Chemex's thick filter slows flow, but if grind is too coarse, water passes before extracting the caramel sweetness that balances the blackcurrant. Finer grind extends contact time within the puck itself.
thin: Add 1g dose or reduce water by 15g. The Chemex strips oils aggressively — for a Bourbon-Marsellesa blend at medium-light roast, the paper removes body compounds alongside defect oils. Increasing dose counteracts the TDS loss; the pecan character needs concentration to register through the filter.
AeroPress at 84°C may seem counterintuitive for a medium-light roast, but the combination of immersion contact, pressure assist, and the bean's elevated Maillard development means lower temperature still achieves full extraction of the sweet compounds. The Bourbon-Marsellesa blend at 1,775m Peruvian altitude has enough density that pressure-assisted extraction compensates for cooler water — the piston press forces water through grounds regardless of diffusion rate. Grind at 390μm, substantially finer than pour-over settings, because the short 1–2 minute brew time requires high surface area to extract caramel and pecan character before time runs out. The 1:12.3–1:13.3 ratio produces a concentrated shot that amplifies the brown sugar sweetness and blackcurrant depth that defines this lot.
Troubleshooting
sour: Grind finer by ~22μm and raise temp by 1°C. At 84°C, this blend sits near the lower threshold for extracting the caramelization compounds that balance the blackcurrant acidity. If the grind is even slightly coarse, the short brew window exits before sweetness develops.
thin: Add 1g dose or reduce water by 15g. AeroPress at this ratio already concentrates the cup, but if Marsellesa's denser cell structure resists soluble release, a small dose increase or metal filter swap will push TDS into range without bitterness at this roast level.
The Clever Dripper's hybrid mechanism — full immersion during steep, then drip drawdown through paper — offers a useful middle ground for this Bourbon-Marsellesa blend. Immersion during the 3–4 minute steep allows the Marsellesa's denser structure time to surrender its caramel and brown sugar compounds into fully saturated water, while the paper filter's drawdown phase strips out the oils that would amplify Marsellesa's Robusta-adjacent earthiness at lower roast levels. Here at medium-light, that earthiness is already converted to pecan character — the filter is a net benefit. Grind at 520μm, identical to the Kalita, because the flat-bottom drawdown geometry resembles the Kalita's flow characteristics. Temperature holds at 93°C — steep temperature drops during immersion, so starting at 93°C lands slurry closer to the optimal 88–90°C range.
Troubleshooting
sour: Grind finer by ~22μm and raise temp by 1°C. The Clever's immersion phase is time-bounded — if the grind is too coarse, the Bourbon and Marsellesa components haven't surrendered their Maillard compounds before drawdown begins. Finer grind accelerates extraction during steep.
thin: Add 1g dose or reduce water by 15g. Even with full immersion, Peru at 1,775m has moderate soluble density. If TDS is low, the brown sugar and blackcurrant notes won't register. A small dose increase is the most direct fix at this ratio.
Espresso at 92°C — 1°C below standard — reflects the medium-light roast's improved but still developing solubility. At 240μm grind, the espresso recipe targets the range where both Bourbon and Marsellesa behave predictably under pressure. Pressure extraction at 9 bar concentrates all compounds dramatically — the blackcurrant's dark fruit acidity and the brown sugar sweetness both amplify. The 1:1.3–1:2.3 output ratio sits close to the standard 1:2 espresso range, with the slightly longer end giving this medium-light roast enough water contact to reach full extraction and avoid sour notes. Expect the pecan character to emerge as nuttiness in the finish under pressure extraction.
Troubleshooting
sour: Grind finer by ~10μm and raise temp by 1°C. Medium-light Marsellesa-Bourbon espresso sits close to the extraction edge — the blend's modest solubility means the shot exits at the acid phase if puck resistance is too low. Even 10μm finer grind meaningfully extends extraction into the sweet caramel register.
thin: Add 1g dose or reduce output water by 15g. At 1:1.3–1:2.3 ratio this is already a longer pull than traditional espresso — if the shot still tastes thin, the Peru medium-light's moderate soluble load needs more coffee mass to hit TDS targets under pressure.
Moka pot operates at roughly 1.5 bar — far below espresso's 9 bar but above atmospheric — which makes it a moderate concentrator of flavor. For this Bourbon-Marsellesa blend, the elevated 340μm grind is notably coarser than espresso because moka pot's slower pressure build lets water spend more time in the basket: fine grind here creates over-extraction and the bitter compounds from over-extraction that medium-light roast hasn't fully converted. Pre-boiling the water before filling the base is critical — cold water sitting in the bottom chamber cooks the grounds with rising steam before extraction begins, which aggressively over-extracts the Marsellesa's CGAs. At 99°C boiling-point effective start, this recipe pushes the top of the temperature envelope for medium-light to drive extraction through the coarser grind.
Troubleshooting
sour: Grind finer by ~22μm and ensure water is pre-boiled before filling. Moka pot sour usually means the basket is passing water too quickly. At medium-light roast, the blackcurrant acidity dominates if caramelization compounds aren't reached — finer grind slows the flow enough to extract them.
strong: Reduce dose by 1g or increase water by 15g. Moka pot is inherently a concentrating method — at medium-light roast, the Bourbon component's full extraction can produce over-strength output that turns the brown sugar sweetness into cloying intensity. Small dose adjustments have outsize TDS effects here.
French press removes the paper filter entirely, which means Marsellesa's Sarchimor-lineage oils pass unimpeded into the cup — at medium-light roast this is a modest advantage, adding body that the Chemex or V60 would strip. The 990μm grind is coarse but pulled 10μm below default: the medium-light roast drives a 20μm finer adjustment, while the Marsellesa variety offsets 10μm coarser to account for its hybrid characteristics. Brewing at 95°C compensates for the coarse grind's lower surface area and the lower extraction efficiency of immersion methods. The extended 4–8 minute window allows the diffusion gradient to even out, giving both Bourbon's delicate citric acidity and the Marsellesa's brown-sugar character time to fully extract.
Troubleshooting
sour: Grind finer by ~22μm and raise temp by 1°C. French press immersion means dissolved compounds compete with each other — if the coarse grind limits early extraction, the cup exits at the acid phase before sweetness develops. Even 22μm finer dramatically changes surface area at this particle size range.
thin: Add 1g dose or reduce water by 15g. French press retains fines in the cup — if the brew still tastes thin, the Peru altitude's moderate soluble density needs more coffee mass to hit target TDS, as the coarse grind isn't maximizing extraction efficiency.
Cold BrewFlash 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.