{ "id": "honey-process", "url": "https://coffearium.org/entries/honey-process/", "license": "CC-BY-4.0", "title": "Honey process", "summary": "A processing method in which the skin and pulp are removed and the seed is dried with part or all of its mucilage still on – between washed and natural coffee.", "domain": "post-harvest-processing", "kind": "Method", "stage": "process", "topics": [], "topicSections": {}, "lang": "en", "status": "verified", "reviewer": "Coffearium verification pass", "lastVerified": "2026-10-08T00:00:00.000Z", "updated": "2026-10-08T00:00:00.000Z", "brief": [ "The skin and pulp are removed by a pulper, and the seed is dried with some or all of its mucilage still attached, instead of having it washed off.1,13", "The amount of mucilage left on is set by the pulping or demucilaging machine, or by a shortened fermentation.7,8,18", "White, yellow, red and black honey are producer conventions. Published definitions give different amounts of mucilage for the same colour, and no standard exists.1,18", "Honey coffee dries faster than natural coffee, but the sticky layer needs thin layers, frequent turning and good ventilation to avoid clumping and local fermentation.6" ], "quickFacts": [ { "label": "Fruit removed", "value": "Skin and pulp, before drying" }, { "label": "Left on the seed", "value": "Part or all of the mucilage" }, { "label": "Mucilage kept", "value": "About 20–100%, no standard" }, { "label": "How it is set", "value": "Pulper or demucilager settings; shortened fermentation" }, { "label": "Drying time", "value": "About 8–30 days by grade (one review); 12–30 days (another)" }, { "label": "Dried as", "value": "Parchment coated in mucilage" }, { "label": "End moisture", "value": "10–12% wb (Cenicafé trial)" } ], "aka": [ "Honey processing", "Miel process" ], "linkTerms": [ "honey coffee", "honey coffees", "honey-processed", "honey processed", "white honey", "yellow honey", "red honey", "black honey" ], "related": [ "mucilage", "washed-process", "natural-process", "pulped-natural", "pulping", "mechanical-demucilaging", "drying", "fermentation", "microorganisms" ], "contested": [ "Mucilage kept per colour: a 2016 review gives about 25% for yellow and about 50% for red, with black usually fully covered1; a 2023 review gives black, red, yellow and white as 80% down to 20% of the pulp material left on the seed.18 Neither refers to a standard.", "Drying time: about 8, 12 and 30 days for yellow, red and black honey in a 2016 review1, 12 to 30 days in a 2023 review.18 A Cenicafé trial dried all its coffees in a thin layer in 3–6 days.7", "What the names mean: several sources treat honey, pulped natural and semi-dry as one method6,8,13; a 2016 review describes pulped natural as a separate route using pressure-washing machines1; a Colombian study uses \"semi-dry\" for coffee that is fermented but not washed16; and \"semi-washed\" has three meanings – pulped coffee dried in its mucilaginous parchment in the Codex code of practice19, pulped coffee demucilaged by machine without fermentation in an FAO manual20, and wet-hulled coffee for an importer.21", "Sucrose: Brazilian semi-dry coffees held more sucrose than wet-processed coffees of the same cultivars3, while a parallel comparison of wet and dry processing found sucrose not significantly affected.17 The two studies compare different pairs of methods." ], "corrections": [], "sources": [ { "id": "s1", "title": "Challenges in Specialty Coffee Processing and Quality Assurance", "authors": "Poltronieri, P.; Rossi, F.", "year": 2016, "publisher": "Challenges 7(2), 19", "url": "https://www.mdpi.com/2078-1547/7/2/19", "doi": "10.3390/challe7020019", "tier": "A", "quote": "A yellow honey (approx. 25% mucilage) typically has the least cloud/shade cover during drying in order to speed up the drying time to about 8 days, and will gain a yellow colour.", "accessed": "2026-09-30T00:00:00.000Z" }, { "id": "s2", "title": "Characterization of volatile compounds and microbial diversity of Arabica coffee in honey processing method based on different mucilage retention treatments", "authors": "Hu, F.; Yu, H.; Fu, X.; Li, Z.; Dong, W.; Li, G.; Li, Y.; Li, Y.; Qu, B.; Bi, X.", "year": 2025, "publisher": "Food Chemistry: X 25, 102251", "url": "https://www.sciencedirect.com/science/article/pii/S2590157525000987", "doi": "10.1016/j.fochx.2025.102251", "tier": "A", "quote": "HS-SPME-GC–MS revealed that the RH group (75 % to 80 % mucilage retention) had the highest relative content of volatile compounds.", "accessed": "2026-09-30T00:00:00.000Z" }, { "id": "s3", "title": "Chlorogenic acids and other relevant compounds in Brazilian coffees processed by semi-dry and wet post-harvesting methods", "authors": "Duarte, G. S.; Pereira, A. A.; Farah, A.", "year": 2010, "publisher": "Food Chemistry 118(3), 851–855", "url": "https://www.sciencedirect.com/science/article/pii/S0308814609006840", "doi": "10.1016/j.foodchem.2009.05.042", "tier": "A", "quote": "Coffees processed by wet method showed higher contents of chlorogenic acids (p = 0.02) and trigonelline (p < 0.01), and lower content of sucrose (p = 0.02) compared to those produced by a semi-dry method.", "accessed": "2026-09-30T00:00:00.000Z" }, { "id": "s4", "title": "Condutividade elétrica como indicador do café despolpado durante a desgomagem", "authors": "Lima, M. V.; Vieira, H. D.; Martins, M. L. L.", "year": 2008, "publisher": "Ciência Rural 38(6), 1765–1768", "url": "https://www.redalyc.org/pdf/331/33113632044.pdf", "doi": "10.1590/s0103-84782008000600044", "tier": "A", "quote": "retira-se apenas a casca do fruto e este é levado para secagem com a mucilagem aderida ao pergaminho", "accessed": "2026-09-30T00:00:00.000Z" }, { "id": "s5", "title": "Risk Assessment of Coffee Cherry (Cascara) Fruit Products for Flour Replacement and Other Alternative Food Uses", "authors": "Eckhardt, S.; Franke, H.; Schwarz, S.; Lachenmeier, D. W.", "year": 2022, "publisher": "Molecules 27(23), 8435", "url": "https://www.mdpi.com/1420-3049/27/23/8435", "doi": "10.3390/molecules27238435", "tier": "A", "quote": "However, no fermentation occurs after this process; instead, the mucilage remains on the bean and is dried along with it.", "accessed": "2026-09-30T00:00:00.000Z" }, { "id": "s6", "title": "Advances in coffee drying: A comprehensive review of traditional, solar, mechanical, hybrid, and emerging methods", "authors": "Duque-Dussán, E.; Figueroa-Varela, P. A.; Cruz-Ospina, V.; Banout, J.", "year": 2026, "publisher": "Foods 15(10), 1737", "url": "https://www.mdpi.com/2304-8158/15/10/1737", "doi": "10.3390/foods15101737", "tier": "A", "quote": "Honey coffees dry faster than the natural ones but still require strict control of layer thickness, frequent turning, and adequate ventilation to prevent clumping and localized fermentation", "accessed": "2026-09-30T00:00:00.000Z" }, { "id": "s7", "title": "Producción de café con fermentaciones incompletas y fermentaciones prolongadas utilizando el Fermaestro®", "authors": "Sanz-Uribe, J. R.; Velásquez-Henao, J.", "year": 2022, "publisher": "Revista Cenicafé 73(1)", "url": "https://publicaciones.cenicafe.org/index.php/cenicafe/article/view/203", "doi": "10.38141/10778/73105", "tier": "A", "quote": "probabilidades entre 22% y 77% de obtener tazas con defectos sensoriales", "accessed": "2026-09-30T00:00:00.000Z" }, { "id": "s8", "title": "Pulped-Natural and Honey Processed Coffee", "authors": "Royal NY Trader Group", "year": 2020, "publisher": "Royal New York (green coffee importer)", "url": "https://www.royalny.com/blogs/pulped-natural-and-honey-processed-coffee/", "tier": "B", "quote": "Pulped- natural and honey processing are different names for the same production style.", "accessed": "2026-09-30T00:00:00.000Z" }, { "id": "s9", "title": "What Is Honey Coffee?", "authors": "Sweet Maria's", "year": 2024, "publisher": "Sweet Maria's Coffee Library (green coffee importer)", "url": "https://library.sweetmarias.com/what-is-honey-coffee/", "tier": "B", "quote": "It's a term that became popularized in Costa Rica (called Miel coffee) as another way to describe the \"pulp-natural process,\" which is then name used in Brazil for some time prior to anyone saying \"honey coffee\".", "accessed": "2026-09-30T00:00:00.000Z" }, { "id": "s10", "title": "Effect of processing methods (washed, honey, natural, anaerobic) of catimor coffee on physical and sensory quality in Alto Inambari, Peru", "authors": "Antezana, R. N. V.; Luna-Mercado, G. I.", "year": 2023, "publisher": "Coffee Science 18, e182111", "url": "https://coffeescience.ufla.br/index.php/Coffeescience/article/view/2111", "doi": "10.25186/.v18i.2111", "tier": "A", "quote": "the total cup score was: 82.50 (control), 84.00 (washed), 82.88 (honey), 85.75 (natural) and 87.38 (anaerobic)", "accessed": "2026-09-30T00:00:00.000Z" }, { "id": "s11", "title": "Characterization of the volatile flavour compounds in Yunnan Arabica coffee prepared by different primary processing methods using HS-SPME/GC-MS and HS-GC-IMS", "authors": "Zhai, H.; Dong, W.; Tang, Y.; Hu, R.; Yu, X.; Chen, X.", "year": 2024, "publisher": "LWT 192, 115717", "url": "https://www.sciencedirect.com/science/article/pii/S0023643823012963", "doi": "10.1016/j.lwt.2023.115717", "tier": "A", "quote": "honey processing methods (MA, MB, and MC) enhanced the caramel, roasted aroma, and buttery flavor of coffee samples.", "accessed": "2026-09-30T00:00:00.000Z" }, { "id": "s12", "title": "Pulped natural/honey robusta coffee fermentation metabolites, physico-chemical and sensory profiles", "authors": "Aswathi, K. N.; Shirke, A.; Praveen, A.; Chaudhari, S. R.; Murthy, P. S.", "year": 2023, "publisher": "Food Chemistry 429, 136897", "url": "https://www.sciencedirect.com/science/article/abs/pii/S0308814623015157", "doi": "10.1016/j.foodchem.2023.136897", "tier": "A", "quote": "The HC fermentation (192 h) influenced carbohydrates, organic acids, and secondary metabolites besides flavor precursors compared to WC (72 h).", "accessed": "2026-09-30T00:00:00.000Z" }, { "id": "s13", "title": "Effect of Three Post-Harvest Methods at Different Altitudes on the Organoleptic Quality of C. canephora Coffee", "authors": "Velásquez, S.; Banchón, C.; Chilán, W.; Guerrero-Casado, J.", "year": 2022, "publisher": "Beverages 8(4), 83", "url": "https://www.mdpi.com/2306-5710/8/4/83", "doi": "10.3390/beverages8040083", "tier": "A", "quote": "In the honey (semi-dry or pulped natural) approach, the coffee skin and pulp are removed using a pulping machine.", "accessed": "2026-09-30T00:00:00.000Z" }, { "id": "s14", "title": "Inoculation of starter cultures in a semi-dry coffee (Coffea arabica) fermentation process", "authors": "Evangelista, S. R.; Miguel, M. G. C. P.; Cordeiro, C. S.; Silva, C. F.; Pinheiro, A. C. M.; Schwan, R. F.", "year": 2014, "publisher": "Food Microbiology 44, 87–95", "url": "https://www.sciencedirect.com/science/article/pii/S0740002014001191", "doi": "10.1016/j.fm.2014.05.013", "tier": "A", "quote": "DGGE analysis showed that the inoculated yeasts were present throughout the fermentation.", "accessed": "2026-09-30T00:00:00.000Z" }, { "id": "s15", "title": "Optimization and Scale-Up of Coffee Mucilage Fermentation for Ethanol Production", "authors": "Orrego, D.; Zapata-Zapata, A. D.; Kim, D.", "year": 2018, "publisher": "Energies 11(4), 786", "url": "https://www.mdpi.com/1996-1073/11/4/786", "doi": "10.3390/en11040786", "tier": "A", "quote": "it consists of 85–91% (w/w) water, 6.2–7.4% (w/w) sugars and small amounts of protein", "accessed": "2026-09-30T00:00:00.000Z" }, { "id": "s16", "title": "Effect of the postharvest processing method on the biochemical composition and sensory analysis of arabica coffee", "authors": "Rodriguez, Y. F. B.; Guzman, N. G.; Hernandez, J. G.", "year": 2020, "publisher": "Engenharia Agrícola 40(2), 177–183", "url": "https://www.scielo.br/j/eagri/a/nCDnLMm8qf8YVtXNw84YVzm/?lang=en", "doi": "10.1590/1809-4430-eng.agric.v40n2p177-183/2020", "tier": "A", "quote": "In the semi-dry method, beans are fermented but not washed.", "accessed": "2026-09-30T00:00:00.000Z" }, { "id": "s17", "title": "Influence of processing on the content of sugars in green Arabica coffee beans", "authors": "Knopp, S.; Bytof, G.; Selmar, D.", "year": 2006, "publisher": "European Food Research and Technology 223, 195–201", "url": "https://link.springer.com/article/10.1007/s00217-005-0172-1", "doi": "10.1007/s00217-005-0172-1", "tier": "A", "quote": "Sucrose, the major low molecular sugar in green coffee beans, is not significantly affected by coffee processing.", "accessed": "2026-09-30T00:00:00.000Z" }, { "id": "s18", "title": "Coffee fermentation: Expedition from traditional to controlled process and perspectives for industrialization", "authors": "Elhalis, H.; Cox, J.; Zhao, J.", "year": 2023, "publisher": "Applied Food Research 3(1), 100253", "url": "https://www.sciencedirect.com/science/article/pii/S2772502222002086", "doi": "10.1016/j.afres.2022.100253", "tier": "A", "quote": "The resultant beans are called black, red, yellow or white honey beans based on the amount of the remaining pulp materials attached to the beans from 80% to 20%, accordingly (Priyadi et al., 2021).", "accessed": "2026-10-08T00:00:00.000Z" }, { "id": "s19", "title": "Code of Practice for the Prevention and Reduction of Ochratoxin A Contamination in Coffee (CAC/RCP 69-2009)", "authors": "Codex Alimentarius Commission (FAO/WHO)", "year": 2009, "publisher": "Codex Alimentarius", "url": "https://www.fao.org/input/download/standards/11250/CXP_069e.pdf", "tier": "A", "quote": "direct drying of the pulped beans within their mucilaginous parchment, followed by hulling to produce \"semi-washed\" green coffee.", "accessed": "2026-10-08T00:00:00.000Z" }, { "id": "s20", "title": "Arabica coffee manual for Lao-PDR", "authors": "Winston, E.; Op de Laak, J.; Marsh, T.; Lempke, H.; Chapman, K.", "year": 2005, "publisher": "FAO Regional Office for Asia and the Pacific, Bangkok", "url": "https://www.fao.org/4/ae939e/ae939e08.htm", "tier": "A", "quote": "Notably this process does not ferment the mucilage as it is mechanically removed by a demucilager.", "accessed": "2026-10-08T00:00:00.000Z" }, { "id": "s21", "title": "Wet-Hulled (aka Semi-Washed, Sumatra Process, Giling Basah)", "publisher": "Cafe Imports", "url": "https://www.cafeimports.com/europe/blog/?p=37563", "tier": "B", "quote": "Wet-Hulled (aka Semi-Washed, Sumatra Process, Giling Basah)", "accessed": "2026-10-08T00:00:00.000Z" } ], "markdown": "## How it works\n\nHoney processing removes the skin and pulp in a pulper but leaves the mucilage – wholly or in part – on the parchment while the coffee dries.1,13 There is no fermentation tank and no wash: the mucilage stays on the seed and dries with it.5,13 After drying, the parchment is removed in a huller, as for washed coffee.13\n\nIt therefore sits between the two classic families. Washed coffee loses skin, pulp and mucilage before drying; natural coffee keeps all three; honey coffee keeps only the mucilage, or part of it.5,6\n\n
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    \n
  1. Washed. Skin, pulp and mucilage are removed before drying; clean parchment goes to the bed.5,6
    2. \n
  2. Honey grades. Pulped but not washed: the mucilage, or part of it, dries on the parchment.1,5 White, yellow, red and black are producer conventions with no standard.1,18
    3. \n
  3. White honey. 20% of the pulp material left on the seed, in a 2023 review.18
    4. \n
  4. Yellow honey. About 25% of the mucilage kept, in a 2016 review.1
    5. \n
  5. Red honey. About 50%, in the same 2016 review.1
    6. \n
  6. Black honey. Usually fully covered in the 2016 review;1 80% of the pulp material in the 2023 review.18
    7. \n
  7. Natural. Skin, pulp and mucilage all stay on while the coffee dries.5,6
    8. \n
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What stays on the seed while it dries, from washed through the honey grades to natural; the two reviews that give figures define the grades differently. Schematic, not to scale.
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What stays on the seed during drying in the three processing families. Honey coffee belongs to the semi-dry family: pulped and dried with mucilage on the parchment.5 The Codex code of practice calls green coffee from pulped beans dried in their mucilaginous parchment \"semi-washed\" – one of three meanings of that term.19
\n
\n\n## Setting the amount of mucilage\n\nThe point of the method is to choose how much mucilage dries on the seed. Two ways are reported:\n\n- **Machine settings.** A 2023 review describes the depulping step as adjusted to keep a specific amount of material around the seeds.18 A green-coffee importer reports that higher water pressure and faster rotor speeds remove more mucilage, and that the coffee then dries faster.8\n- **A shortened fermentation.** Cenicafé made honey coffees by stopping tank fermentation early, at about 25%, 50% and 75% mucilage breakdown, and compared them with coffee not degraded at all.7\n\nThe review literature describes the result as anything from about 20% to 80% of the mucilage kept.1,18 In one review, black honey usually keeps all of it.1\n\n## The colour grades\n\nWhite, yellow, red and black honey are producer conventions, not defined grades. The two sources that give figures disagree:\n\n- A 2016 review gives about 25% for yellow and about 50% for red, with black usually fully covered.1\n- A 2023 review, citing a study of smallholders, gives black, red, yellow and white honey as 80% down to 20% of the pulp material left on the seed.18\n\nThe 2016 review also ties the colour to drying, not only to the amount kept. Yellow honey dries with the least shade or cloud cover in about 8 days; red honey takes about 12 days under cloud or shade; black honey dries over about 30 days.1 An importer likewise links lighter honeys to quick drying in hot, dry weather, and darker ones to cool, humid conditions.8 A \"yellow honey\" from one farm may therefore not match a \"yellow honey\" from another.\n\n## Drying\n\nSticky mucilage changes how the coffee dries. Honey coffee dries faster than natural coffee, but it needs strict control of layer thickness, frequent turning and good ventilation to prevent clumping and local fermentation.6 Drying time can be steered by the depth of the bed and how often it is turned.8\n\nPublished drying times vary widely:\n\n- About 8, 12 and 30 days for yellow, red and black honey in one review.1\n- 12 to 30 days in another review, without a split by grade.18\n- 3–6 days in a thin layer in the sun, from 53% to 10–12% moisture (wet basis), in the Cenicafé trial.7\n\nThe review that gives the drying times calls further drying of pulped natural coffee a highly sensitive step that must be supervised constantly.1\n\n## Names and history\n\n\"Honey\" is a name from the coffee trade. According to two green-coffee importers, it was popularised in Costa Rica – as *miel* – for what was already done in Brazil under the name pulped natural.8,9 A 2023 review names Costa Rica and El Salvador among the countries that produce it.18 In Brazil the method is called *cereja descascado* (CD): only the skin is removed, and the fruit is dried with the mucilage attached to the parchment.4 Brazilian research also calls it semi-dry3: the pulp is removed, there is no fermentation, and the mucilage dries on the seed.5\n\nThe names do not line up exactly:\n\n- **Honey = pulped natural = semi-dry.** A 2026 drying review, a 2022 study and an importer all treat them as one method.6,13,8\n- **Pulped natural as a separate route.** A 2016 review describes pulped natural as removing the pulp with pressure-washing machines and lists it apart from honey.1\n- **\"Semi-dry\" for fermented but unwashed coffee.** A Colombian study uses semi-dry for beans that are fermented but not washed.16\n- **\"Semi-washed\" has three meanings.** The Codex code of practice, whose definitions follow ISO 3509, calls pulped coffee dried directly in its mucilaginous parchment and then hulled \"semi-washed\" green coffee – that is, honey-type coffee.19 An FAO manual for Lao PDR uses \"semi-washed\" for coffee whose mucilage is removed by a demucilager straight after pulping, without fermentation20; that coffee dries without mucilage and belongs with washed coffee. In the trade, an importer lists \"semi-washed\" as another name for Indonesian wet-hulled coffee.21 Check which of the three an author means by \"semi-washed\".\n\nWhen comparing studies, check what the authors actually did, not which name they used.\n\n\n\n## Reference protocol by grade\n\nThe table brings together the values reported in the sources. Grades are conventions; each row gives each source's own definition.\n\n| Parameter | White honey | Yellow honey | Red honey | Black honey |\n|---|---|---|---|---|\n| Mucilage kept, 2016 review | – | About 25%1 | About 50%1 | Usually 100%1 |\n| Pulp material left on, 2023 review | 20%18 | – | – | 80%18 |\n| Shade during drying (review) | – | Least shade or cloud cover1 | Cloud cover or shading1 | Drying prolonged1 |\n| Drying time (review) | – | About 8 days1 | About 12 days1 | About 30 days1 |\n\n| Parameter | Value reported | Source |\n|---|---|---|\n| Pulping | Skin and pulp removed by a pulping machine | Velásquez et al.13 |\n| Setting the level | Depulper adjusted to keep a specific amount; more water pressure and rotor speed remove more | Elhalis et al.18, Royal New York8 |\n| Fermentation route | Tank fermentation stopped at about 25%, 50% or 75% mucilage breakdown | Sanz-Uribe & Velásquez-Henao7 |\n| Drying | Sun; thin layer; frequent turning; good ventilation | Sanz-Uribe & Velásquez-Henao7, Duque-Dussán et al.6 |\n| Drying levers | Bed depth, turning frequency | Royal New York8 |\n| Drying time, all grades | 12–30 days (2023 review) | Elhalis et al.18 |\n| Moisture at start of drying | 53% (wet basis) | Sanz-Uribe & Velásquez-Henao7 |\n| End moisture | 10–12% (wet basis) | Sanz-Uribe & Velásquez-Henao7 |\n| Mechanical drying | Rotary dryers suit honey coffees, where stickiness can hinder airflow | Duque-Dussán et al.6 |\n\n
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Drying days reported for honey coffee in two reviews and one trial. Each source dried under its own conditions; the Cenicafé range covers all its treatments.1,7,18
\n
\n\n## Drying physics with a mucilage layer\n\nMucilage is mostly water – 85–91% (w/w) in a compilation cited by one study – with 6.2–7.4% sugars.15 Keeping more mucilage therefore means more of this watery, sugary layer on the parchment to dry.15\n\nTwo effects follow in the sources:\n\n- **Stickiness.** Residual mucilage makes the coffee sticky, which can hinder airflow through the mass.6 Wet beans cluster; continuous agitation in rotary dryers reduces local over- or under-drying and limits microbial activity by preventing this clustering.6\n- **Speed against shade.** The review that links colour to drying uses shade and cloud cover to slow drying for the darker grades, and full sun to speed it up for yellow.1 An importer reports the same direction: more mucilage removed, faster drying.8\n\nNone of the sources opened for this entry gives drying curves for different retention levels under the same conditions. How much each extra 10% of mucilage adds to drying time is not known from published data.\n\n## Microbiology on drying honey coffee\n\nWithout a tank, microbes still act on the mucilage of pulped coffee: researchers study \"semi-dry\" fermentation and the communities on honey coffees directly.2,14\n\n- **Communities shift with the amount of mucilage.** In a 2025 Arabica study, bacteria were more active at low mucilage retention and fungi at high retention.2 The study found seven dominant bacterial and four dominant fungal genera, and fungal diversity was higher than bacterial diversity across treatments.2\n- **Semi-dry Arabica.** Bacteria in a semi-dry trial with starter yeasts included *Weissella*, *Leuconostoc*, *Gluconobacter*, *Pseudomonas*, *Pantoea*, *Erwinia* and *Klebsiella*; other yeasts detected included *Debaryomyces hansenii*.14 Inoculated yeasts persisted throughout the fermentation, and the inoculated coffee showed a caramel flavour missing from the control.14\n- **Robusta.** In a 2023 study, honey Robusta was fermented for 192 hours against 72 hours for washed coffee, with effects on carbohydrates, organic acids and flavour precursors.12\n\n## Chemistry and cup\n\n**Composition.** Seventeen Brazilian Arabica cultivars processed wet had more chlorogenic acids and trigonelline and less sucrose than the same cultivars processed semi-dry; caffeine did not differ.3 A parallel comparison of wet and dry processing of Arabica found sucrose not significantly affected, while glucose and fructose were significantly lower in washed coffee.17 A Colombian study of Castillo coffee found differences in colour, pH and caffeine between its wet and \"semi-dry\" (fermented, unwashed) coffees, but none in titratable acidity, chlorogenic acid or cup score.16\n\n**Aroma.** In a 2025 Arabica study, the treatment that kept 75–80% of the mucilage had the highest relative content of volatile compounds.2 A Yunnan study compared seven processing methods and found that its three honey methods enhanced caramel, roasted and buttery notes.11 In a 2023 Robusta study, honey coffee showed more pleasant, sweet, tea-rose and chocolate notes than washed coffee.12\n\n**Cup scores.** Honey does not automatically score between washed and natural. In a Peruvian trial with Catimor, honey scored 82.88, below washed (84.00) and natural (85.75); of the sensory attributes, only fragrance and body differed significantly between methods.10 In the Cenicafé trial, cup scores did not differ statistically between treatments.7 For *C. canephora* in Ecuador, the Conilon type had its best sensory attributes at high altitude with honey processing.13\n\n
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Total cup scores by processing method in one trial with Catimor coffee in Peru – not a general ranking.10
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\n\n## Risks and defects\n\n- **Defective cups from partial removal.** In the Cenicafé trial, making honey coffees by stopping fermentation early carried a 22–77% probability of cups with sensory defects.7\n- **Clumping and local fermentation.** Thick layers, rare turning or poor ventilation let sticky beans clump and ferment in place.6\n- **Uneven drying.** Clusters of wet beans dry unevenly; agitation reduces local over- and under-drying.6\n- **Fungal load.** Fungi are more active at high mucilage retention.2 The sources here do not link specific grades to mould defects or ochratoxin A.\n- **Supervision.** Drying pulped natural coffee is a sensitive step that needs constant supervision.1\n\n## Measuring the process\n\nMoisture is tracked from the start of drying to the end point – in the Cenicafé trial from 53% down to 10–12% (wet basis).7\n\n## Open questions\n\n- **No standard.** Colour names mean different amounts of mucilage in different sources, and one ties them to drying conditions as well.1,18\n- **Colour: mucilage or drying?** Whether the colour of the dried parchment comes mainly from the amount kept or from drying speed has not been tested head-to-head in the sources opened here.1,8\n- **Sugars.** Semi-dry coffee held more sucrose than wet in one study3; how glucose and fructose in honey coffee compare with washed and natural coffee is not measured in the sources here.\n- **Microbial succession.** The trials report communities at selected points; how they change day by day across drying for each grade is still open.2,14\n\n## Key studies\n\n
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Hu et al., 2025 – Mucilage retention in honey processing. Compared Arabica honey-process treatments that kept different amounts of mucilage, using volatile analysis and sequencing of microbial communities. The treatment keeping 75–80% gave the highest relative content of volatile compounds; bacteria were more active at low and fungi at high mucilage levels.

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Food Chemistry: X 25, 102251 · doi:10.1016/j.fochx.2025.102251

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Duarte et al., 2010 – Semi-dry versus wet in Brazil. Seventeen Arabica cultivars and progenies were processed both ways. Wet-processed seeds had more chlorogenic acids and trigonelline and less sucrose; caffeine did not change.

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Food Chemistry 118(3), 851–855 · doi:10.1016/j.foodchem.2009.05.042

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Sanz-Uribe & Velásquez-Henao, 2022 – Incomplete fermentations. Cenicafé stopped fermentation at set levels of mucilage breakdown to make honey coffees. Cup scores did not differ statistically between treatments, but the authors estimate a 22–77% probability of defective cups when honey coffee is made this way.

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Revista Cenicafé 73(1) · doi:10.38141/10778/73105

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Antezana & Luna-Mercado, 2023 – Four methods on one lot. Catimor from Alto Inambari, Peru, was processed washed, honey, natural and anaerobic, against a control. Honey scored lowest of the three classic methods in this trial, and anaerobic highest.

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Coffee Science 18, e182111 · doi:10.25186/.v18i.2111

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Zhai et al., 2024 – Volatiles across seven methods. Compares seven primary processing methods for Yunnan Arabica – three dry, one wet and three honey variants – with two gas-chromatography techniques. The three honey methods raised caramel, roasted and buttery aroma notes.

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LWT 192, 115717 · doi:10.1016/j.lwt.2023.115717

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