{ "id": "serving-temperature", "url": "https://coffearium.org/entries/serving-temperature/", "license": "CC-BY-4.0", "title": "Serving temperature", "summary": "How hot coffee is served and drunk, how the flavour changes as a cup cools, how fast it cools, and what burn research and the World Health Organization’s cancer agency say about very hot drinks.", "domain": "science", "kind": "Concept", "stage": "cup", "topics": [ "science" ], "topicSections": {}, "lang": "en", "status": "verified", "reviewer": "Coffearium verification pass", "lastVerified": "2026-10-15T00:00:00.000Z", "updated": "2026-10-15T00:00:00.000Z", "added": "2026-10-15T00:00:00.000Z", "brief": [ "In consumer studies of black coffee, preferred temperatures ranged from about 60 to 71 °C; the reported optimum depends on the method used.1", "In a 2022 study of 118 consumers, acceptance of black coffee was highest at 58–66 °C; above 70 °C, most found it too hot.5", "Temperature changes perceived flavour. Hot coffee was rated more roasted and less often bitter in one study; sourness rose as coffee cooled in another.6,8", "The SCA cupping standard starts tasting at about 70 °C and continues until the coffee is below body temperature.12", "The International Agency for Research on Cancer (IARC) classifies drinking very hot beverages, above 65 °C, as probably carcinogenic to humans (Group 2A).15,16" ], "quickFacts": [ { "label": "Preferred, black coffee", "value": "Means and optima of 57.8–71.4 °C across six studies (2019 review)" }, { "label": "Highest acceptance", "value": "58–66 °C (118 consumers, 2022)" }, { "label": "“Too hot” on average", "value": "66–67 °C (87 participants, 2018; abstract and table differ)" }, { "label": "Cupping", "value": "Water 93 ± 3 °C; tasting from about 70 °C to below body temperature" }, { "label": "IARC “very hot”", "value": "Above 65 °C; Group 2A, probably carcinogenic (2016)" }, { "label": "Coffee itself (IARC)", "value": "Group 3, not classifiable (2016)" }, { "label": "Cooling in a room", "value": "Typically 10–15 °C in 5 min (2019 review)" }, { "label": "Lid (cap)", "value": "Roughly doubles the required cooling time (2019 review)" } ], "aka": [ "Drinking temperature", "Coffee temperature" ], "linkTerms": [ "serving temperature", "drinking temperature", "preferred drinking temperature", "very hot beverages", "hot beverages", "scald", "scalds", "scald burn" ], "related": [ "cupping", "how-we-taste-coffee", "the-aroma-of-coffee", "body-and-mouthfeel", "sensory-science-methods", "cups-and-vessels", "crossmodal-effects", "coffee-and-long-term-health", "brew-methods", "cold-brew", "caffeine", "brew-temperature" ], "contested": [ "Preferred temperature and pain: two consumer studies from one research group found that preferred drinking temperatures lay above the thermal pain and thermal damage thresholds2,3; a 2018 study that let each participant find their own limit found an average preferred temperature (63 °C) below the average “too hot” temperature (66–67 °C; the paper gives both values).4 The studies define the thresholds differently.", "Bitterness and temperature: in a 2018 consumer study, fewer participants chose “bitter” for coffee at 65 °C than at 25 or 5 °C6; a 2018 thesis found bitterness lowest in its lukewarm sample, with no difference between the hottest and the coldest8; physiology research reports that warming enhances perceived bitterness and sweetness.10 The studies measured different things at different temperatures.", "Acidity and temperature: a textbook chapter says drinkers often report more fruity and acid flavours as coffee cools9, and a 2018 thesis found sourness rose as samples cooled8; in a 2022 consumer study, tasting temperatures of 56–71 °C had little effect on how adequate consumers found the acidity.5", "Best serving temperature: the reported optimum ranges from 57.8 °C, a calculated compromise between preference and burn risk, to 71.4 °C, the most preferred temperature in a ranking study as reported in a 2019 review (a 2022 paper reports 72.1 °C for the same study)1; the methods (ranking, mixing hot and cold coffee, just-about-right scales, calculation) differ.1,5" ], "corrections": [], "sources": [ { "id": "s1", "title": "A Review of Hot Beverage Temperatures – Satisfying Consumer Preference and Safety", "authors": "Abraham, J. P.; Diller, K. R.", "year": 2019, "publisher": "Journal of Food Science 84(8), 2011–2014", "url": "https://foodsci.oregonstate.edu/sites/agscid7/files/foodsci/attachments/hot-bev-temp.pdf", "doi": "10.1111/1750-3841.14699", "tier": "A", "quote": "The top-ranked temperature was 68.3 °C (155 °F), followed by 62.8 °C (145 °F).", "accessed": "2026-10-15T00:00:00.000Z" }, { "id": "s2", "title": "At what temperatures do consumers like to drink coffee?: Mixing methods", "authors": "Lee, H. S.; O’Mahony, M.", "year": 2002, "publisher": "Journal of Food Science 67(7), 2774–2777", "url": "https://pure.ewha.ac.kr/en/publications/at-what-temperatures-do-consumers-like-to-drink-coffee-mixing-met/", "doi": "10.1111/j.1365-2621.2002.tb08814.x", "tier": "A", "quote": "In all experiments, the chosen mean preferred temperature for drinking was around 60°C (140°F).", "abstractOnly": true, "accessed": "2026-10-15T00:00:00.000Z" }, { "id": "s3", "title": "Hedonic R-index measurement of temperature preferences for drinking black coffee", "authors": "Pipatsattayanuwong, S.; Lee, H. S.; Lau, S.; O’Mahony, M.", "year": 2001, "publisher": "Journal of Sensory Studies 16(5), 517–536", "url": "https://pure.ewha.ac.kr/en/publications/hedonic-r-index-measurement-of-temperature-preferences-for-drinki/", "doi": "10.1111/j.1745-459X.2001.tb00317.x", "tier": "A", "quote": "Preferred temperatures were above thermal pain and thermal damage thresholds.", "abstractOnly": true, "accessed": "2026-10-15T00:00:00.000Z" }, { "id": "s4", "title": "What Temperature of Coffee Exceeds the Pain Threshold? Pilot Study of a Sensory Analysis Method as Basis for Cancer Risk Assessment", "authors": "Dirler, J.; Winkler, G.; Lachenmeier, D. W.", "year": 2018, "publisher": "Foods 7(6), 83", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC6025158", "doi": "10.3390/foods7060083", "tier": "A", "quote": "The descriptive statistical analysis gives a mean value of 63 °C with a standard deviation of 3 °C.", "accessed": "2026-10-15T00:00:00.000Z" }, { "id": "s5", "title": "Impact of beverage temperature on consumer preferences for black coffee", "authors": "Ristenpart, W. D.; Cotter, A. R.; Guinard, J.-X.", "year": 2022, "publisher": "Scientific Reports 12, 20621", "url": "https://www.nature.com/articles/s41598-022-23904-4", "doi": "10.1038/s41598-022-23904-4", "tier": "A", "quote": "None of the 118 consumers assessed the hottest coffee presented to them as too cold.", "accessed": "2026-10-15T00:00:00.000Z" }, { "id": "s6", "title": "Influences of Product Temperature on Emotional Responses to, and Sensory Attributes of, Coffee and Green Tea Beverages", "authors": "Pramudya, R. C.; Seo, H.-S.", "year": 2018, "publisher": "Frontiers in Psychology 8, 2264", "url": "https://www.frontiersin.org/articles/10.3389/fpsyg.2017.02264/full", "doi": "10.3389/fpsyg.2017.02264", "tier": "A", "quote": "Coffee and green tea are popular beverages consumed at both hot and cold temperatures.", "accessed": "2026-10-15T00:00:00.000Z" }, { "id": "s7", "title": "Coffee Flavor: A Review", "authors": "Seninde, D. R.; Chambers, E., IV", "year": 2020, "publisher": "Beverages 6(3), 44", "url": "https://www.mdpi.com/2306-5710/6/3/44", "doi": "10.3390/beverages6030044", "tier": "A", "quote": "Results showed that consumption temperature was critical to the flavor profiles of each of the samples.", "accessed": "2026-10-15T00:00:00.000Z" }, { "id": "s8", "title": "Effects of Serving Temperature on Sensory Perception and Acceptance of Brewed Coffee", "authors": "Chapko, M. J.", "year": 2018, "publisher": "University of Arkansas, MSc thesis (Food Science)", "url": "https://scholarworks.uark.edu/cgi/viewcontent.cgi?article=4483&context=etd", "tier": "B", "tierNote": "Master’s thesis (Tier B under the tier decision of 8 Oct 2026); used only for directions of change, without numbers.", "quote": "Perception of sourness intensity increased as the sample temperature decreased", "accessed": "2026-10-15T00:00:00.000Z" }, { "id": "s9", "title": "The Brew – Extracting for Excellence", "authors": "Mestdagh, F.; Glabasnia, A.; Giuliano, P.", "year": 2017, "publisher": "In: Folmer, B. (ed.), The Craft and Science of Coffee, Academic Press, ch. 15, pp. 355–380", "url": "https://doi.org/10.1016/B978-0-12-803520-7.00015-3", "doi": "10.1016/B978-0-12-803520-7.00015-3", "tier": "B", "quote": "Contrarily the above-cup aroma is higher with increasing temperature.", "accessed": "2026-10-15T00:00:00.000Z" }, { "id": "s10", "title": "Heat activation of TRPM5 underlies thermal sensitivity of sweet taste", "authors": "Talavera, K.; Yasumatsu, K.; Voets, T.; Droogmans, G.; Shigemura, N.; Ninomiya, Y.; Margolskee, R. F.; Nilius, B.", "year": 2005, "publisher": "Nature 438(7070), 1022–1025", "url": "https://ideas.repec.org/a/nat/nature/v438y2005i7070d10.1038_nature04248.html", "doi": "10.1038/nature04248", "tier": "A", "tierNote": "The quote is from the abstract text shown on RePEc, which reads like Nature’s editorial summary; used only for the background statement and the TRPM5 mechanism.", "quote": "It is well known that warming enhances perceived sweetness and bitterness.", "abstractOnly": true, "accessed": "2026-10-15T00:00:00.000Z" }, { "id": "s11", "title": "Cupping and Grading – Discovering Character and Quality", "authors": "Lingle, T. R.; Menon, S. N.", "year": 2017, "publisher": "In: Folmer, B. (ed.), The Craft and Science of Coffee, Academic Press, ch. 8, pp. 181–203", "url": "https://www.sciencedirect.com/book/9780128035207/the-craft-and-science-of-coffee", "doi": "10.1016/B978-0-12-803520-7.00008-6", "tier": "B", "quote": "The sequence of rating each attribute is based on the flavor perception changes caused by decreasing temperature of the coffee as it cools", "accessed": "2026-10-15T00:00:00.000Z" }, { "id": "s12", "title": "SCA Standard 102-2024 Coffee Value Assessment: Sample Preparation and Tasting Mechanics", "authors": "Specialty Coffee Association", "year": 2024, "publisher": "Specialty Coffee Association", "url": "https://sca.coffee/s/AW_SCA-102_Sample-Preparation_281024_Secured.pdf", "tier": "A/B", "tierNote": "A for the procedure, temperatures and limits the standard specifies; B for its explanations.", "quote": "After each cup has been skimmed, the brew should be allowed to cool to about 70°C before “liquoring” begins.", "accessed": "2026-10-15T00:00:00.000Z" }, { "id": "s13", "title": "SCA Standard 103-2024 Coffee Value Assessment: Descriptive Assessment", "authors": "Specialty Coffee Association", "year": 2024, "publisher": "Specialty Coffee Association", "url": "https://sca.coffee/s/AW_SCA-103_Descriptive-Assessment_Sept2024_Secured.pdf", "tier": "A/B", "tierNote": "A for the definitions the standard specifies; B for its explanations.", "quote": "The tactile perception of the brew while it is in the mouth, excluding the temperature perception.", "accessed": "2026-10-15T00:00:00.000Z" }, { "id": "s14", "title": "SCA Standard 104-2024 Coffee Value Assessment: Affective Assessment", "authors": "Specialty Coffee Association", "year": 2024, "publisher": "Specialty Coffee Association", "url": "https://sca.coffee/s/AW_SCA-104_Affective-Assessment_Sept2024_Secured.pdf", "tier": "A/B", "tierNote": "A for the procedure the standard specifies; B for its explanations.", "quote": "If the impression of quality shifted as the coffee cooled down, a second bubble should be filled, signaling the direction of change with an arrow.", "accessed": "2026-10-15T00:00:00.000Z" }, { "id": "s15", "title": "IARC Monographs evaluate drinking coffee, maté, and very hot beverages (Press release N° 244)", "authors": "International Agency for Research on Cancer", "year": 2016, "publisher": "International Agency for Research on Cancer (WHO), Lyon, 15 June 2016", "url": "https://www.iarc.who.int/wp-content/uploads/2018/07/pr244_E.pdf", "tier": "A", "quote": "Drinking very hot beverages was classified as probably carcinogenic to humans (Group 2A).", "accessed": "2026-10-15T00:00:00.000Z" }, { "id": "s16", "title": "Drinking Coffee, Mate, and Very Hot Beverages (IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol. 116)", "authors": "IARC Working Group on the Evaluation of Carcinogenic Risks to Humans", "year": 2018, "publisher": "International Agency for Research on Cancer (WHO), Lyon; pp. 33–34 cited", "url": "https://publications.iarc.fr/_publications/media/download/5598/f49696e5e7a10f69ff3fc1cc673b3f77b4e8af43.pdf", "tier": "A", "quote": "The Working Group concluded that drinking very hot beverages (> 65 °C) is probably carcinogenic to humans (Group 2A)", "accessed": "2026-10-15T00:00:00.000Z" }, { "id": "s17", "title": "Review of the initial treatment and avoidance of scald injuries", "authors": "Bourdon, R. T.; Nelson-Cheeseman, B. B.; Abraham, J. P.", "year": 2017, "publisher": "World Journal of Dermatology 6(2), 17–26", "url": "https://wjgnet.com/2218-6190/full/v6/i2/17.htm", "doi": "10.5314/wjd.v6.i2.17", "tier": "A", "quote": "The experiments were carried out in typical ambient conditions of about 20 °C.", "accessed": "2026-10-15T00:00:00.000Z" }, { "id": "s18", "title": "How would you like your tea, vicar?", "authors": "Jamnadas-Khoda, B.; See, M. S.; Cubison, C. T. C.; Dheansa, B. S.", "year": 2010, "publisher": "Burns 36(3), 356–359", "url": "https://pubmed.ncbi.nlm.nih.gov/19586723/", "doi": "10.1016/j.burns.2009.04.024", "tier": "A", "quote": "Black tea and black coffee remained at temperatures greater than 65 degrees C despite cooling for 10 min.", "abstractOnly": true, "accessed": "2026-10-15T00:00:00.000Z" } ], "markdown": "## How hot people drink coffee\n\nCoffee is brewed much hotter than people like to drink it.1 The Specialty Coffee Association (SCA) specifies water at 93 ± 3 °C for cupping.12 Consumer studies place the preferred drinking temperature of coffee well below that.1\n\nResearchers have measured preference in several ways. In one approach, consumers mixed a hot and a cooler coffee until it reached the temperature they wanted. About 300 people did this in a first experiment; across the experiments, the mean was around 60 °C.2 Black-coffee drinkers chose slightly higher temperatures than people who added creamer.2 In a 2018 pilot study, 87 participants drank instant coffee and warmed it step by step until it felt too hot. Their preferred temperature averaged 63 °C.4\n\nA 2022 study asked 118 consumers whether each coffee was too cold, too hot or “just about right”. Each person tasted 27 black coffees between 56 and 71 °C.5 Acceptance was highest at 58–66 °C.5 Only above 70 °C did most consumers find the coffee too hot.5 Even at 68 °C, a few percent still found it somewhat too cold.5\n\nStudies of black coffee report preferred or optimal temperatures from 57.8 to 71.4 °C, according to a 2019 review.1 Part of the spread comes from method: ranking set temperatures, mixing, rating on scales or calculating an optimum.1,5 People also differ. In the 2018 pilot study, 72% of participants preferred their coffee below 65 °C and 22% above it.4\n\n
\n
\n
Preferred or optimal drinking temperatures of coffee from a 2019 review1 and two later studies.4,5 Hollow marks show the IARC “very hot” threshold15 and the start of SCA cupping.12 The 2008 value is a calculated compromise between preference and burn risk, not a measured preference.1
\n
\n\n## How temperature changes flavour\n\nTemperature changes what a taster perceives, not only how the cup feels.7 In a study summarised in a 2020 review, a trained panel tasted four coffees at 50, 60 and 70 °C.7 The review sums up its result: consumption temperature was critical to the flavour profile of every sample.7 Coffee identity and fidelity grew stronger as the temperature rose.7\n\nStudies of single attributes point in different directions.6,8\n\n- **Aroma.** More aroma rises above a hotter cup, because aroma compounds leave the liquid more readily when it is hot.9 In a 2018 thesis study, the hottest samples had the strongest aroma.8\n- **Roasted notes.** In a 2018 consumer study, 63% chose “roasted flavour” for coffee at 65 °C. Only 33–37% chose it at 25 or 5 °C.6\n- **Bitterness.** In the same study, 67% chose “bitter” at 65 °C and 84% at 25 or 5 °C.6 The thesis study found a different pattern: bitterness was lowest in its lukewarm sample.8\n- **Acidity.** A textbook chapter states that drinkers often report more fruity and acid flavours as coffee cools.9 The thesis study found that sourness rose as samples cooled.8 In the 2022 consumer study, by contrast, temperature had little effect on how adequate the acidity seemed.5\n- **Sweetness.** Physiology research reports that warming enhances perceived sweetness and bitterness.10 In the 2018 consumer study, sweetness was not among the attributes that changed with temperature.6\n\nAccording to the textbook chapter, tasting a cooling coffee is a changing experience: tasters also get used to some flavours, so others seem to appear.9 The 2018 thesis concluded that subtle attributes may be easier to identify in coffee served cooler.8\n\n## Temperature in cupping\n\nCupping uses the cooling of the cup on purpose. The SCA standard specifies that the brew cools to about 70 °C before tasting, or “liquoring”, begins.12 At least three rounds of tasting follow as the coffee cools below body temperature.12 If a cupper’s impression changes as the coffee cools, the affective form allows a second rating. An arrow marks the direction of change.14\n\nThe SCA’s descriptive standard defines mouthfeel as the tactile feel of the brew, excluding the temperature perception.13 Heat is therefore not part of mouthfeel in the CVA. The earlier SCAA protocol also ordered its attributes by temperature, according to a textbook chapter. The sequence followed how flavour perception changes as coffee cools.11 How cupping works step by step is covered in *Cupping*.\n\n\n\n## Reference values\n\nValues as reported in the sources. Preferences are for black coffee unless stated.\n\n| Parameter | Value reported | Source |\n|---|---|---|\n| Cupping water | 93 ± 3 °C | SCA 102-202412 |\n| Start of tasting in cupping | Brew cooled to about 70 °C | SCA 102-202412 |\n| End of tasting in cupping | At least three rounds, until below body temperature | SCA 102-202412 |\n| Preferred, mixing method (≈300 consumers, with additions to taste) | Mean around 60 °C | Lee & O’Mahony2 |\n| Preferred, mixing method, as reviewed | 59.8 °C (all 300 subjects); 61.5 °C (black-coffee drinkers) | Abraham & Diller1 |\n| Best of seven temperatures (top-ranked in the review; closest to just-about-right in the 2022 paper) | 68.3 °C; review: followed by 62.8 °C | Borchgrevink et al., in Abraham & Diller1 and Ristenpart et al.5 |\n| Most preferred (ranking, R-index) | 71.4 °C (review); 72.1 °C (2022 paper) | Pipatsattayanuwong et al., in Abraham & Diller1 and Ristenpart et al.5 |\n| Optimal, black coffee | 70.8 °C | Stokes et al., in Abraham & Diller1 |\n| Calculated optimum (preference and burn risk) | 54–60 °C; 57.8 °C | Brown & Diller, in Abraham & Diller1 and Dirler et al.4 |\n| Preferred, step-wise warming (87 participants, instant coffee) | Mean 63 °C (SD 3 °C) | Dirler et al.4 |\n| Perceived as too hot (same study) | Mean 67 °C (abstract) or 66 °C (results, Table 1); individual limits 58–71 °C | Dirler et al.4 |\n| Highest acceptance (118 consumers, 56–71 °C tested) | 58–66 °C | Ristenpart et al.5 |\n| Lowest temperature at which no one found it too cold | 68–70 °C | Ristenpart et al.5 |\n| Cooling in a room | Typically 10–15 °C in 5 min | Abraham & Diller1 |\n| Cooling with a lid (cap) | Required cooling time roughly doubled | Abraham & Diller1 |\n| Drop when coffee or tea is poured into a cup | 2–5 °C | Abraham & Diller1 |\n| 237 mL served at 95 °C, uncovered, ≈20 °C room | 77.2 · 65.5 · 57.7 · 53.6 · 53.3 °C after 5 · 10 · 15 · 20 · 25 min | Bourdon et al.17 |\n| 473 mL served at 95 °C, uncovered, ≈20 °C room | 82.3 · 73.9 · 67.9 · 64.4 · 63.3 °C after 5 · 10 · 15 · 20 · 25 min | Bourdon et al.17 |\n| Black coffee in a 230 mL ceramic mug, 22 °C room | Above 65 °C after 10 min | Jamnadas-Khoda et al.18 |\n| Milky drinks, same study | Starting temperature 75–77 °C | Jamnadas-Khoda et al.18 |\n| IARC “very hot” | Above 65 °C; drinking very hot beverages Group 2A | IARC15,16 |\n| Drinking coffee (IARC) | Group 3, not classifiable as to its carcinogenicity to humans | IARC15,16 |\n\nValues marked “in Abraham & Diller” are reported in that 2019 review; the original papers were not opened for this entry, except the abstracts of Lee & O’Mahony and Pipatsattayanuwong et al.1,2,3\n\n## How preference is measured\n\nThe methods give different answers because they ask different questions.\n\n- **Fixed temperatures.** Judges rate or rank coffees served at set temperatures. One study rated seven temperatures between 57.2 and 90.6 °C on a just-about-right scale; another ranked six between 39.2 and 82.1 °C.5 The result can only be one of the temperatures offered.\n- **Mixing.** Consumers mix hot and cold coffee until they reach the temperature they want.2,5 The 2018 pilot study used a variant: participants started at 60 °C and added hot coffee from a 0.04 L beaker, each addition raising the temperature by 2–3 °C, until it felt too hot.4\n- **Just-about-right scales.** The 2022 study did not set temperatures. They varied naturally with brewing and cooling, and each tasting was recorded with a just-about-right rating and a 9-point liking score.5 Judging the temperature too hot or too cold cost only about 0.4 points of liking; flavour intensity and acidity that missed the mark cost 1.2–1.9 points.5\n- **Calculation.** The 2008 optimum of 57.8 °C combines preference data with a model of burn risk.1,4\n\nWho is asked and what they drink also matters. The 2018 pilot study used instant coffee in insulated foam cups, with 87 participants.4 The 2022 study served about 30 mL of one washed Honduran coffee in 120 mL paper cups; it was funded by the SCA, with underwriting by an appliance maker.5 Two studies from one research group found that preferred temperatures lay above the thermal pain and thermal damage thresholds.2,3 Their judges ranked similar temperatures as most likely to be served in a coffee shop, and customers observed in coffee shops began sipping at similarly high temperatures.3\n\n## Heat on the tongue\n\nCoffee in the cup is hotter than the surface it touches. The 2018 pilot study estimates by formula that coffee at 70 °C gives a contact temperature of about 55–57 °C; the paper gives both values.4 It cites measurements showing that coffee at 60 °C may raise the tongue surface to 53 °C.4 The heat-sensitive TRPV1 receptors open above 43 °C, and a painful heat sensation begins above about 44–45 °C.4 On average, its participants found coffee too hot at 66–67 °C, about 3 °C above the temperature they preferred.4\n\nTemperature also acts on taste cells directly. Receptors for sweet, bitter and umami signal through the ion channel TRPM5, which is itself activated by heat.10 This is offered as a molecular explanation for why warming enhances perceived sweetness and bitterness.10 Only the abstract of that study was read for this entry, so its temperature range is not given here.\n\n## Flavour across temperatures: the studies\n\n**Descriptive panels.** In the study summarised in a 2020 review, seven trained panelists rated 36 attributes in two arabicas, one robusta and a blend at 50, 60 and 70 °C.7 Temperature interacted with the coffee: attributes such as fullness, fidelity and balance changed differently from sample to sample.7 The review therefore advises considering the coffee and the temperature together when developing hot coffee flavour profiles.7 A 2018 thesis with a trained panel found that serving temperature had a larger effect on perception than the choice of coffee.8 Aroma, roasted and cocoa notes were strongest in the hottest samples; stale and tobacco notes, sourness and astringency were stronger in the coldest.8\n\n**Consumers.** In a 2018 study, 79 black-coffee drinkers described brewed coffee served at 65, 25 and 5 °C with check-all-that-apply lists. Six attributes differed with temperature.6 Roasted aroma and roasted flavour were chosen more often for hot coffee; bitter taste, metallic and skunky flavours more often for cold coffee.6 Pungent aroma was the sixth attribute. The total number of sensory terms chosen did not change with temperature.6\n\n**Why aroma changes.** Volatile compounds dissolve better in cooler liquid, so a hot brew releases more of them into the air above the cup.9 According to the textbook chapter, the coffee may also keep changing chemically after serving.9\n\nThe panel and consumer studies served each sample at a set temperature.6,8 A cupper tastes one coffee as it cools, and according to the textbook chapter, habituation then adds to the effect of temperature.9\n\n
\n
\n
    \n
  1. Brewing water. The SCA specifies 93 ± 3 °C for cupping.12
    2. \n
  2. Tasting starts. Cupping begins once the brew has cooled to about 70 °C.12
    3. \n
  3. “Very hot”. Above 65 °C, the IARC classifies drinking very hot beverages as probably carcinogenic to humans (Group 2A).15,16
    4. \n
  4. Highest acceptance. In a 2022 study of 118 consumers, black coffee was best accepted at 58–66 °C.5
    5. \n
  5. Below body temperature. Cupping continues in at least three rounds until the coffee is below body temperature.12
    6. \n
\n
The reference points of this entry on one temperature column, placed at their relative heights; the dashed line marks the IARC threshold at the level of the coffee in the cup. Our own drawing. Schematic, not to scale.
\n
\n\n## How fast a cup cools\n\nIn tabulated cooling data, a cup loses heat quickly at first, then more slowly.17 A 2019 review states that hot beverages typically lose 10–15 °C in 5 min in a room, and that a lid roughly doubles the required cooling time.1 Pouring coffee or tea into a cup takes off 2–5 °C.1 In the 2022 consumer study, the coffee lost about 8 °C between brewing and the insulated carafe, and about 12 °C more on pouring small samples into room-temperature paper cups.5\n\nA 2017 review on scald injuries tabulates the cooling of uncovered beverages in a room at about 20 °C.17 A 237 mL drink served at 95 °C reached 65.5 °C after 10 min; a 473 mL drink was still at 73.9 °C after 10 min.17 The review does not separate measured from calculated values in these tables.17 In a 2010 study, black coffee and black tea made in 230 mL ceramic mugs stayed above 65 °C after 10 min of cooling.18 Milky drinks started cooler, at 75–77 °C.18\n\n
\n
\n
Tabulated cooling of uncovered beverages served at 95 °C in a room at about 20 °C, for two volumes; lines join the 5-minute values in the source17, with the IARC “very hot” threshold for reference.15 The source does not say which values were measured and which calculated.
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\n\n**Holding temperatures.** No source opened for this entry measured the temperatures at which cafés hold or serve coffee. A 2019 review estimates that coffee brewed at 93 °C (source: 200 °F) is about 90 °C in the carafe and 85–88 °C in the cup at service.1 A 2017 review notes that beverage service temperatures are often above 82 °C (source: 180 °F).17 The 2022 study advises retail coffee operations to check their actual post-pour temperatures.5\n\n## Scald risk\n\nHot liquids are among the most common causes of burns.17 The 2019 review states that brewing temperatures are high enough to pose an immediate and serious risk of scald injuries.1 It describes the rate of injury as rising very rapidly with each degree of liquid temperature.1 Spills at 82 °C (source: 180 °F) are very likely to cause at least mid-dermal burns, according to the same review.1\n\nChildren are at particular risk, according to both the 2017 review and a 2010 study.17,18 Their skin is about 70% as thick as an adult’s, according to the 2017 review. It calls for lower temperatures or longer cooling for people with limited mobility, such as children or the elderly.17 The 2010 study showed the potential for a full-thickness burn despite 10 min of cooling or the addition of cold milk.18\n\nBoth reviews argue for serving below brewing temperature. The 2019 review proposes a service range of 130–160 °F (≈54–71 °C), on the grounds that preferred drinking temperatures lie significantly below brewing temperatures.1 No authority opened for this entry sets a maximum serving temperature for coffee.\n\n## Very hot beverages and the IARC\n\nIn 2016 a working group of the International Agency for Research on Cancer (IARC), the cancer agency of the World Health Organization, evaluated drinking coffee, maté and very hot beverages; the IARC announced the results on 15 June 2016.15,16 Its conclusions, as published:\n\n- **Very hot beverages:** “drinking very hot beverages (> 65 °C) is probably carcinogenic to humans (Group 2A)”.16 “Very hot” refers to any beverage consumed at a temperature above 65 °C.15\n- **Basis:** limited evidence from epidemiological studies of a causal association with cancer of the oesophagus in humans; the working group judged a causal relationship biologically plausible.16\n- **Coffee:** drinking coffee was “not classifiable as to its carcinogenicity to humans (Group 3)”.15,16\n\nThe classification concerns temperature, not a particular drink. In the press release, the IARC director said that “it is the temperature, rather than the drinks themselves, that appears to be responsible”.15 The studies named in the press release come from places such as China, Iran, Turkey and South America, where tea or maté is traditionally drunk very hot, at about 70 °C.15\n\nThe 65 °C line falls inside the range of preferred drinking temperatures. In the 2018 pilot study, 22% of participants preferred their coffee above 65 °C.4 In the 2022 study, acceptance was highest at 58–66 °C.5 The authors of the 2018 study note a lack of research on which temperatures consumers perceive as “very hot” or “too hot”, and propose their method as a basis for cancer risk assessment.4\n\n## Open questions\n\n- **Café temperatures.** No source opened for this entry reports measured serving or holding temperatures in cafés; the reviews give estimates and ranges.1,17\n- **Cup and sip.** The 65 °C threshold refers to the beverage as consumed.15 How sip size, cup material and lids change the temperature that reaches the mouth and oesophagus is not established in the sources opened here.\n- **Bitterness and acidity.** Studies disagree on how bitterness and acidity change as coffee cools (see the contested points below).5,6,8\n- **Specialty coffees.** The two most recent preference studies each used a single coffee: instant coffee in one, a medium-roast washed coffee in the other.4,5 Whether lighter roasts or different origins shift the preferred temperature has not been measured in the sources opened here.\n\n## Key studies\n\n
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Lee & O’Mahony, 2002 – Mixing to a preferred temperature. About 300 consumers mixed hot and cooler coffee, with creamer and sweetener to taste, until it was as hot as they liked; a second experiment varied the strength of black coffee. The mean preferred temperature was around 60 °C in all experiments, with black-coffee drinkers choosing slightly higher temperatures.

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Journal of Food Science 67(7), 2774–2777 · doi:10.1111/j.1365-2621.2002.tb08814.x

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Dirler et al., 2018 – Preferred temperature and the pain threshold. Eighty-seven participants warmed instant coffee step by step until it felt too hot. The mean preferred temperature was 63 °C and the mean “too hot” temperature 66–67 °C (the abstract and the results differ); 22% preferred their coffee above the IARC line of 65 °C.

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Foods 7(6), 83 · doi:10.3390/foods7060083

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Pramudya & Seo, 2018 – Hot, ambient and cold coffee. Seventy-nine black-coffee drinkers described brewed coffee at 65, 25 and 5 °C with check-all-that-apply lists. Six attributes changed with temperature: roasted aroma and flavour were chosen more often for hot coffee, bitterness and metallic notes for cold coffee.

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Frontiers in Psychology 8, 2264 · doi:10.3389/fpsyg.2017.02264

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Ristenpart et al., 2022 – Consumer acceptance by tasting temperature. In 3,186 tastings, 118 consumers rated black coffees between 56 and 71 °C on just-about-right and liking scales. Acceptance peaked at 58–66 °C; only above 70 °C did most find the coffee too hot, and some still found it somewhat too cold at 68 °C.

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Scientific Reports 12, 20621 · doi:10.1038/s41598-022-23904-4

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Abraham & Diller, 2019 – Hot beverage temperatures. A review of consumer preference studies and burn research. It sets the preferred temperatures of six studies against brewing temperatures and argues that serving temperatures should be clearly separated from brewing temperatures.

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Journal of Food Science 84(8), 2011–2014 · doi:10.1111/1750-3841.14699

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\n\n*General information, not medical advice.*" }