{ "id": "cups-and-vessels", "url": "https://coffearium.org/entries/cups-and-vessels/", "license": "CC-BY-4.0", "title": "Cups and vessels", "summary": "What the cup does to coffee once it is poured – how lids, volume and the cup wall change cooling, how the shape of the opening changes aroma, what the cupping standard specifies, and the food-contact rules for cup materials.", "domain": "science", "kind": "Concept", "stage": "cup", "topics": [ "science", "equipment" ], "topicSections": {}, "lang": "en", "status": "verified", "reviewer": "Coffearium verification pass", "lastVerified": "2026-10-21T00:00:00.000Z", "updated": "2026-10-21T00:00:00.000Z", "added": "2026-10-21T00:00:00.000Z", "brief": [ "In tabulated data for drinks served at 95 °C, a cap kept 237 mL at 75.3 °C after 10 min, against 65.5 °C uncovered.4", "A 2019 review states that a cap roughly doubles the required cooling time, and that pouring into a cup takes off 2–5 °C.3", "In a 2018 study with 276 participants, coffee served in a tulip-shaped cup with a narrower opening was rated more aromatic.7", "The Specialty Coffee Association (SCA) specifies cupping vessels of tempered glass or ceramic, 200–350 mL, with a top diameter of 75–90 mm.1", "The German Federal Institute for Risk Assessment (BfR) advises against hot drinks from melamine resin tableware, including “bambooware” coffee-to-go cups.11" ], "quickFacts": [ { "label": "Cap or lid", "value": "Roughly doubles the required cooling time (2019 review)" }, { "label": "Pouring into a cup", "value": "2–5 °C lost (2019 review, several cup types)" }, { "label": "Cupping vessel (SCA 102-2024)", "value": "Tempered glass or ceramic; 200–350 mL; top diameter 75–90 mm; all identical" }, { "label": "Lead from deep ceramic vessels", "value": "4.0 mg/L maximum release (German ordinance, ceramic articles deeper than 25 mm)" }, { "label": "Melamine resin (EU limit)", "value": "Melamine 2.5 mg/kg food; formaldehyde 15 mg/kg food (as reported by the BfR, 2020)" } ], "aka": [ "Coffee cups", "Cup shape", "Coffee mug" ], "linkTerms": [ "cups and vessels", "coffee cup", "coffee mug", "cup shape", "tulip cup", "cupping vessel", "cupping bowl", "paper cup", "reusable cup", "bambooware" ], "related": [ "serving-temperature", "crossmodal-effects", "cupping", "the-aroma-of-coffee", "how-we-taste-coffee", "espresso", "carbon-footprint-of-coffee", "packaging", "contaminants-and-food-safety", "coffee-drinks-around-the-world" ], "contested": [], "corrections": [ { "date": "2026-10-21T00:00:00.000Z", "change": "Cup-shape study: the split cup was liked least by the consumers, not by the professionals; the listed limitations now follow the paper (cup weights not matched, expectations not measured, one coffee).", "reason": "The paper reports lower liking for the split cup among amateurs only and does not state that temperature was left uncontrolled." }, { "date": "2026-10-21T00:00:00.000Z", "change": "Removed the reusable versus single-use cup footprint figures (4.6 and 8.6 kg CO₂e) and the Scottish Government report they came from.", "reason": "The report page could not be opened during verification, so the figures could not be checked." }, { "date": "2026-10-21T00:00:00.000Z", "change": "German ceramic rules now cite the official text; the lid rule and the 50% tolerance rule are stated as the ordinance words them.", "reason": "The tolerance needs at least three other items of the same kind, none of them above the limit by more than 50%; the lid rule applies to ceramic lids." } ], "sources": [ { "id": "s1", "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, materials and dimensions the standard specifies; B for its explanations.", "quote": "All cups used shall be of identical volume, dimensions, and material of manufacture.", "accessed": "2026-10-21T00:00:00.000Z" }, { "id": "s2", "title": "A System to Assess Coffee Value: Understanding the Specialty Coffee Association’s Coffee Value Assessment (June 2024)", "authors": "Specialty Coffee Association (writing team Fernández-Alduenda, M.; Ionescu, K. E.; Giuliano, P.; Rugolo, J.; Delrue, R.)", "year": 2024, "publisher": "Specialty Coffee Association", "url": "https://static1.squarespace.com/static/584f6bbef5e23149e5522201/t/667182ffdde8a5081afc2d8c/1718715138872/SCA+-+A+System+to+Asssess+Coffee+Value+-+June+2024+(Secured).pdf", "tier": "A/B", "tierNote": "A for what the CVA itself specifies (procedure, vessels); B for its explanations.", "quote": "All cups used shall be of identical volume, dimensions, and material of manufacture, and have lids.", "accessed": "2026-10-21T00:00:00.000Z" }, { "id": "s3", "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 use of a cap approximately doubles the required cooling time.", "accessed": "2026-10-21T00:00:00.000Z" }, { "id": "s4", "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", "tierNote": "Values from Tables 2–5 (opened on the journal’s table page, wjgnet.com/2218-6190/tables/v6/i2/17.htm); the tables do not say which values were measured and which calculated.", "quote": "The experiments were carried out in typical ambient conditions of about 20 °C.", "accessed": "2026-10-21T00:00:00.000Z" }, { "id": "s5", "title": "Comprehensive method to predict and quantify scald burns from beverage spills", "authors": "Abraham, J. P.; Nelson-Cheeseman, B. B.; Sparrow, E.; Wentz, J. E.; Gorman, J. M.; Wolf, S. E.", "year": 2016, "publisher": "International Journal of Hyperthermia 32(8), 900–910", "url": "https://researchexperts.utmb.edu/en/publications/comprehensive-method-to-predict-and-quantify-scald-burns-from-bev/", "doi": "10.1080/02656736.2016.1211752", "tier": "A", "quote": "the presence or absence of a cap and the presence or absence of an insulating corrugated paper sleeve.", "abstractOnly": true, "accessed": "2026-10-21T00:00:00.000Z" }, { "id": "s6", "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": "2026-10-21T00:00:00.000Z" }, { "id": "s7", "title": "The shape of the cup influences aroma, taste, and hedonic judgements of specialty coffee", "authors": "Carvalho, F. M.; Spence, C.", "year": 2018, "publisher": "Food Quality and Preference 68, 315–321", "url": "https://ora.ox.ac.uk/objects/uuid:9d682018-0494-4e31-a556-f18de37ea5fc/files/m2d0bc4ddab12a0ed76b6303d6c9a8d2f", "doi": "10.1016/j.foodqual.2018.04.003", "tier": "A", "tierNote": "Accepted manuscript in the University of Oxford repository.", "quote": "the coffee was rated as more aromatic by the participants who received their sample in the tulip cup", "accessed": "2026-10-21T00:00:00.000Z" }, { "id": "s8", "title": "A sniffer-camera for imaging of ethanol vaporization from wine: the effect of wine glass shape", "authors": "Arakawa, T.; Iitani, K.; Wang, X.; Kajiro, T.; Toma, K.; Yano, K.; Mitsubayashi, K.", "year": 2015, "publisher": "Analyst 140(8), 2881–2886", "url": "https://pubs.rsc.org/en/Content/ArticleLanding/2015/AN/C4AN02390K", "doi": "10.1039/C4AN02390K", "tier": "A", "tierNote": "A study of wine, not coffee; cited only to show that vapour above a drink is unevenly distributed and depends on the vessel’s shape.", "quote": "a characteristic ring shape attributed to high alcohol concentration appeared near the rim", "abstractOnly": true, "accessed": "2026-10-21T00:00:00.000Z" }, { "id": "s9", "title": "Bedarfsgegenständeverordnung (BedGgstV), Anlage 6 (zu § 8 Absatz 3 und § 10 Absatz 2 Satz 3): Bedarfsgegenstände, von denen bestimmte Stoffe nur bis zu einer festgelegten Höchstmenge auf Lebensmittel übergehen dürfen", "authors": "Germany (federal ordinance)", "year": 1998, "publisher": "Bedarfsgegenständeverordnung, BGBl. I 1998, 32, as amended; official text at gesetze-im-internet.de (Federal Ministry of Justice)", "url": "https://www.gesetze-im-internet.de/bedggstv/anlage_6.html", "tier": "A", "tierNote": "Official German law, opened on gesetze-im-internet.de (the page shows no date of last amendment). The annex does not name the EU directive it implements.", "quote": "Der Behälter allein und die innere Oberfläche des Deckels werden unter den gleichen Bedingungen getrennt geprüft.", "accessed": "2026-10-21T00:00:00.000Z" }, { "id": "s10", "title": "Schwermetalle aus Keramikglasuren können die Gesundheit gefährden (Presseinformation 08/2005)", "authors": "Bundesinstitut für Risikobewertung (BfR)", "year": 2005, "publisher": "Bundesinstitut für Risikobewertung, Berlin, 11 March 2005", "url": "https://www.bfr.bund.de/presseinformation/schwermetalle-aus-keramikglasuren-koennen-die-gesundheit-gefaehrden/", "tier": "A", "quote": "Farbige Glasuren von Keramikgeschirr können Schwermetalle wie Blei oder Cadmium enthalten.", "accessed": "2026-10-21T00:00:00.000Z" }, { "id": "s11", "title": "Fillable articles made from melamine formaldehyde resin, such as coffee-to-go cups sold as ‘bambooware’, may leak harmful substances into hot foods (BfR Opinion No 046/2019)", "authors": "Bundesinstitut für Risikobewertung (BfR)", "year": 2020, "publisher": "Bundesinstitut für Risikobewertung, Berlin, 25 November 2020", "url": "https://www.bfr.bund.de/cm/349/fillable-articles-made-from-melamine-formaldehyde-resin.pdf", "tier": "A", "quote": "The formaldehyde release from about 24% of the ‘bambooware’ articles was exceptionally high.", "accessed": "2026-10-21T00:00:00.000Z" }, { "id": "s12", "title": "Microplastics and other harmful substances released from disposable paper cups into hot water", "authors": "Ranjan, V. P.; Joseph, A.; Goel, S.", "year": 2021, "publisher": "Journal of Hazardous Materials 404, 124118", "url": "https://kgpchronicle.iitkgp.ac.in/?p=6258", "doi": "10.1016/j.jhazmat.2020.124118", "tier": "A/B", "tierNote": "Peer-reviewed paper (volume 2021, Crossref metadata checked), but the paper itself was not opened; method and values are taken from the summary published by the authors’ own university, IIT Kharagpur (undated news page). A/B for that reason; its numbers are labelled in the text as the university’s summary.", "quote": "25,000 micron-sized (10 µm to 1000 µm) microplastic particles are released into 100 mL of hot liquid (85 – 90 oC)", "accessed": "2026-10-21T00:00:00.000Z" }, { "id": "s13", "title": "Common Single-Use Consumer Plastic Products Release Trillions of Sub-100 nm Nanoparticles per Liter into Water during Normal Use", "authors": "Zangmeister, C. D.; Radney, J. G.; Benkstein, K. D.; Kalanyan, B.", "year": 2022, "publisher": "Environmental Science & Technology 56(9)", "url": "https://www.nist.gov/node/1734266", "doi": "10.1021/acs.est.1c06768", "tier": "A", "quote": "Mean particle diameters were between 30 and 80 nm with few particles >200 nm.", "abstractOnly": true, "accessed": "2026-10-21T00:00:00.000Z" }, { "id": "s14", "title": "EU. Lead and Cadmium Migration Limits in Ceramic FCMs", "authors": "European Chemicals Agency (ECHA)", "publisher": "European Chemicals Agency, undated web page listing Council Directive 84/500/EEC (20 October 1984) as amended by Directive 2005/31/EC (30 April 2005)", "url": "https://echa.europa.eu/lead-cadmium-migration-limits-ceramic", "tier": "A", "tierNote": "Undated page, so no year is given; cited as read on the access date. The page names the directive and its amendment but lists no numeric limits.", "quote": "This list contains migration limits for the substances lead and cadmium.", "accessed": "2026-10-21T00:00:00.000Z" }, { "id": "s15", "title": "Disciplinare Caffè Espresso Italiano Tradizionale", "authors": "Issuer not named on the document; every page carries the contact details of COMITCAF (Comitato Italiano del Caffè), Corso di Porta Nuova 34, Milan", "year": 2018, "publisher": "Specification document, no version date stated (file dated 2018)", "url": "https://www.ilcaffeespressoitaliano.com/wp-content/uploads/Disciplinare-Caffè-Espresso-Italiano-Tradizionale-2018.pdf", "tier": "A/B", "tierNote": "A for the parameters and test methods the specification itself sets; B otherwise. Cited only as a specification.", "quote": "Quantità in tazza: quantità di campione erogato, pesato mediante bilancia di precisione.", "accessed": "2026-10-21T00:00:00.000Z" } ], "markdown": "## What the cup does\n\nA cup is more than a container. It takes heat from the coffee, holds the air above it and shapes how a drinker meets the aroma.3,6,7 Its material also touches the hot drink, so food-contact rules apply to it.9,11\n\nThis entry covers four things the vessel does: how it changes cooling, how its shape changes aroma, what the cupping standard specifies, and what the safety rules say about cup materials. How hot people like their coffee, and how flavour changes as it cools, is covered in *Serving temperature*. How colour, weight and shape change expectations is covered in *Crossmodal effects*.\n\n## How the cup changes cooling\n\nCoffee starts losing heat as soon as it is poured. A 2019 review states that pouring coffee or tea into a cup takes off 2–5 °C, based on experiments with several cup types.3 Part of this loss happens because the liquid meets cooler cup walls.3 The open surface then loses heat to the air by convection and evaporation.3\n\nA cap, or lid, slows this down. The same review states that a cap roughly doubles the time a drink needs to cool.3 A 2016 burn study compared drink volume, starting temperature, cooling time, cup material, a cap and a corrugated paper sleeve. The cap, the volume and the cooling time had the most influence.5\n\nA 2017 review tabulates the effect. Drinks served at 95 °C in a room at about 20 °C were followed for 25 min, with and without a cap.4 After 10 min, 237 mL had fallen to 65.5 °C uncovered and to 75.3 °C with a cap.4 A larger 473 mL drink cooled more slowly: 73.9 °C uncovered and 82.3 °C with a cap.4\n\n
\n
\n
Tabulated cooling of a hot beverage served at 95 °C in a room at about 20 °C, for two volumes with and without a protective cap; lines join the 5-minute values in the source.4 The source does not say which values were measured and which calculated.
\n
\n\nWarming a cup before pouring targets the loss at the wall, which the review names as one cause of cooling.3 No study opened for this entry measured how much a preheated cup changes the temperature of coffee.\n\n## How the shape changes aroma\n\nAroma compounds leave hot coffee more readily than cool coffee. A coffee science textbook states that the aroma above the cup rises with temperature.6 Whether the cup’s shape changes what reaches the nose has been tested in one coffee study.\n\nA 2018 study tested this with coffee. At a specialty coffee event in Brazil, 276 people tasted one pour-over coffee from one of three white ceramic cups.7 The cups were the same height but differed in shape: a tulip with a narrower opening, an open cup and a “split” cup with an indentation.7 Coffee in the tulip cup was rated more aromatic.7 Coffee in the split cup was rated sweeter and more acidic; the consumers liked it least, the professionals did not.7\n\nThe vapour above a drink is not even. A 2015 study of wine imaged ethanol vapour above three glasses. In a wine glass, the vapour was strongest in a ring near the rim.8 No comparable imaging study of coffee cups was found for this entry.\n\nHow the colour, weight and texture of a cup change what people expect and perceive is a separate question. It is covered in *Crossmodal effects*.\n\n
\n
\n
    \n
  1. Lid or cap. Roughly doubles the required cooling time3; with a cap, 237 mL served at 95 °C was 75.3 °C after 10 min, against 65.5 °C without.4 The SCA’s CVA document requires lids on cupping vessels.2
    2. \n
  2. Rim and opening. A narrower opening went with higher aroma ratings in one coffee study.7 Above wine, vapour was strongest in a ring near the rim.8
    3. \n
  3. Headspace. The air above the coffee. Above-cup aroma rises with temperature, according to a textbook.6
    4. \n
  4. Open surface. Loses heat by convection and evaporation.3
    5. \n
  5. Wall. A cooler wall takes heat from the drink; pouring into a cup costs 2–5 °C.3
    6. \n
  6. Sleeve. A corrugated paper sleeve was one of the factors tested in a 2016 cooling study.5 A 2017 review reports that the sleeve and the cup’s construction had a very small impact on its results.4
    7. \n
  7. Inner surface. Glazes, resins and linings meet the hot drink; food-contact rules limit what may migrate.9,11
    8. \n
\n
The parts of a cup that matter for heat and aroma. Our own drawing. Schematic, not to scale.
\n
\n\n## The cupping vessel\n\nCupping is the one setting where the vessel is specified. The SCA standard requires cupping vessels of tempered glass or ceramic, holding 200–350 mL, with a top diameter of 75–90 mm.1 All cups in a session must be identical in volume, dimensions and material.1 The SCA’s explanatory CVA document adds that they have lids.2\n\nThe vessel also sets the dose. The volume to the rim can be found by weighing the water the cup holds.1 The coffee dose is then 8.25 g per 150 mL of that capacity.1,2 For a 240 mL vessel this gives 13.20 g.2 How the cupping itself is done is covered in *Cupping*.\n\nNo standard opened for this entry specifies the cup for espresso or other drinks. The traditional Italian espresso specification sets the amount in the cup, 13–26 g, not the cup itself.15\n\n## Materials and safety\n\n**Glazed ceramics.** Coloured glazes on ceramic tableware can contain heavy metals such as lead or cadmium, according to the BfR.10 How much is released depends mainly on the glaze, the firing temperature, the food and the contact time.10 The law therefore limits the release, not the content.9 In German law, deep ceramic vessels may release at most 4.0 mg of lead and 0.3 mg of cadmium per litre in the test.9\n\n**Melamine resin and “bambooware”.** Some reusable coffee-to-go cups are made of melamine formaldehyde resin with bamboo fibres as filler.11 The BfR found that about a quarter of such articles released exceptionally high levels of formaldehyde in its tests.11 It advises against hot meals and drinks from melamine resin tableware, whether conventional or bambooware.11\n\n**Paper cups.** Disposable paper cups for hot drinks have a thin plastic lining; in a 2022 study it was low-density polyethylene.12,13 Two studies found plastic particles released from such cups into hot water.12,13 Their methods, particle sizes and counts differ (see the Deep dive). Contaminants in coffee itself are covered in *Contaminants and food safety*.\n\n**Reusable or single-use.** No life-cycle study of reusable and single-use cups could be checked for this entry. The footprint of the coffee itself is covered in *Carbon footprint of coffee*.\n\n\n\n## Reference values\n\nValues as reported in the sources.\n\n| Parameter | Value reported | Source |\n|---|---|---|\n| Drop on pouring into a cup | 2–5 °C (coffee and tea, several cup types) | Abraham & Diller3 |\n| Typical cooling in a room | 10–15 °C in 5 min | Abraham & Diller3 |\n| Effect of a cap | Required cooling time roughly doubled | Abraham & Diller3 |\n| 237 mL from 95 °C, no cap, ≈20 °C room | 77.2 · 65.5 · 57.7 · 53.6 · 53.3 °C after 5 · 10 · 15 · 20 · 25 min | Bourdon et al.4 |\n| 237 mL from 95 °C, with cap | 83.7 · 75.3 · 68.8 · 64.3 · 61.6 °C after 5 · 10 · 15 · 20 · 25 min | Bourdon et al.4 |\n| 473 mL from 95 °C, no cap | 82.3 · 73.9 · 67.9 · 64.4 · 63.3 °C after 5 · 10 · 15 · 20 · 25 min | Bourdon et al.4 |\n| 473 mL from 95 °C, with cap | 87.5 · 82.3 · 78.3 · 75.5 · 74 °C after 5 · 10 · 15 · 20 · 25 min | Bourdon et al.4 |\n| Most influential cooling factors (2016 study) | Cap, beverage volume, cooling time | Abraham et al.5 |\n| Cupping vessel | Tempered glass or ceramic; 200–350 mL; top diameter 75–90 mm; identical within a session | SCA 102-20241 |\n| Cupping vessel lids | Required (explanatory CVA document) | SCA CVA document2 |\n| Cupping dose | 8.25 g per 150 mL of vessel capacity to the rim; 13.20 g for 240 mL | SCA 102-2024; CVA document1,2 |\n| Ceramic, flat or filling depth ≤25 mm | Lead 0.8 mg/dm²; cadmium 0.07 mg/dm² | BedGgstV Anlage 69 |\n| Ceramic, filling depth >25 mm | Lead 4.0 mg/L; cadmium 0.3 mg/L | BedGgstV Anlage 69 |\n| Ceramic cookware; containers >3 L | Lead 1.5 mg/L; cadmium 0.1 mg/L | BedGgstV Anlage 69 |\n| Melamine, specific migration limit (EU) | 2.5 mg/kg food | BfR Opinion 046/201911 |\n| Formaldehyde, migration limit (EU) | 15 mg/kg food; BfR recommends 6.0 mg/kg | BfR Opinion 046/201911 |\n| Bambooware with exceptionally high formaldehyde release | About 24% of articles tested | BfR Opinion 046/201911 |\n| Microplastics from paper cups | About 25,000 particles of 10–1,000 µm per 100 mL; water at 85–90 °C, 15 min (as summarised by the authors’ university) | Ranjan et al.12 |\n| Nanoparticles from LDPE-lined cups | Above 10¹² per litre; mean diameter 30–80 nm | Zangmeister et al.13 |\n\n## Heat flow in a cup\n\nThe 2019 review names the losses: the cooler wall takes heat when the drink is poured, and the open surface loses heat by convection and evaporation.3 A cap covers the open surface. In the 2017 tables, a capped 237 mL drink was still at 68.8 °C after 15 min; the uncovered one was at 65.5 °C after 10 min.4\n\nVolume also matters. In the same tables, an uncovered 473 mL drink cooled about as slowly as a capped 237 mL one over the first 10 min (our reading of Tables 3 and 4).4 The 2016 study, which included cup material and a paper sleeve among its variables, found cap, volume and time most influential.5 Only its abstract was read for this entry, so its values for single cup materials are not given here. The 2017 review, drawing on the same work, reports that the cup’s construction and an insulating sleeve had a very small impact on its results, and leaves them out of its tables.4\n\n**Warm cups.** The 2019 review names the cooler wall as one reason why poured drinks lose heat.3 Warming the cup removes part of that loss. No study opened for this entry measured the size of the effect for coffee cups, and no sourced heat capacities for cup materials were found, so we give no calculation here.\n\n**Table data and real cafés.** The 2017 tables start at 95 °C, hotter than most coffee in the cup. They do not say which values were measured and which calculated.4 They are useful for comparing cap and volume, not for predicting a particular café cup.\n\n## Shape, headspace and aroma\n\n**Physics.** Volatile compounds dissolve better in cooler liquid. A hot brew therefore releases more of them into the air above the cup, according to the textbook chapter.6 This air above the liquid is called the headspace.\n\n**Coffee study.** In the 2018 cup-shape study, the three cups were white, smooth ceramic, 6.5 cm high and close in weight.7 The tulip cup had a 6.0 cm opening; the open and split cups had 8 cm openings.7 Each participant received about 60 mL of a V60 brew, served at a mean of 58.2 °C.7 Of the 276 analysed participants, 151 worked in specialty coffee and 125 were experienced consumers. Each person rated one cup only.7 Aroma was rated highest in the tulip cup; sweetness and acidity were higher in the split cup, which the consumers liked less than the professionals did.7\n\nThe authors name limits of their design. Cup weights were not matched; taste expectations were not measured; and only one single-origin Arabica was tested.7 The study measured ratings, not the vapour above the cups. Whether the tulip cup concentrated aroma or changed expectations is not settled by it.\n\n**Vapour imaging.** The 2015 wine study shows that headspace vapour can be uneven and shaped by the glass.8 It imaged ethanol, not coffee aroma compounds, and wine at about 13 °C, not hot coffee.8 It is a pointer to a method, not evidence about coffee cups.\n\n## Food-contact rules for cup materials\n\n**Ceramics.** In the EU, lead and cadmium release from ceramic articles is limited by Council Directive 84/500/EEC of 1984, amended in 2005.14 In Germany the limits are set out in Annex 6 of the consumer goods ordinance.9 Limits depend on the article: per area for flat or shallow items, per litre for deeper ones.9 For a ceramic container with a ceramic lid, the container and the inner lid surface are tested separately under the same conditions; the two results are summed and related to the container alone.9 A single test item may exceed a limit by up to 50% if at least three other items of the same material, form, size, decoration and glaze average at or below it, and none of them exceeds it by more than 50%.9 In 2005 the BfR recommended lowering the legal limits, noting that a vessel at the limit could release up to 4 mg of lead per litre of food.10\n\n**Melamine formaldehyde resin.** The BfR’s 2020 opinion found that the release of melamine and formaldehyde at levels relevant for health occurs only at high temperatures.11 Its hot-fill tests ran for 2 hours at 70 °C.11 Melamine release from bambooware was about twice the average of conventional melamine tableware.11 The material appears to degrade with repeated contact with hot liquids, according to the BfR. It considers such tableware unsuitable for the microwave but suitable for food at room temperature.11\n\n**Plastic-lined paper cups.** The two studies differ in what they measured:\n\n- **A 2021 study from India.** Water at 85–90 °C stood in disposable paper cups for 15 min. About 25,000 particles of 10–1,000 µm were counted per 100 mL.12 The paper itself was not opened for this entry; these values come from the summary published by its authors’ university.\n- **A 2022 study from the United States.** Hot beverage cups lined with low-density polyethylene released nanoparticles at above 10¹² per litre when exposed to water.13 Mean diameters were 30–80 nm, with few particles above 200 nm. Release depended on water temperature.13\n\nNeither study, as read for this entry, assessed health effects in people. No food-safety authority opened for this entry has set a limit for particles released from cups.\n\n## Open questions\n\n- **Cup material.** No study opened for this entry compares the cooling of coffee in porcelain, stoneware, glass, double-walled glass and paper under the same conditions with published values.5 One review reports only that cup construction had a very small impact on its results.4\n- **Reusable or single-use.** No life-cycle comparison of cups was checked for this entry; how such studies set functional units and boundaries is explained in *Carbon footprint of coffee*, and rules for packaging in *Packaging*.\n- **Warm cups.** The effect of warming a cup beforehand on coffee temperature, and on flavour, was not measured in the sources opened here.\n- **Aroma in the headspace.** Cup shape changed aroma ratings in one coffee study.7 No study opened for this entry measured coffee aroma compounds above cups of different shapes.\n- **Revised ceramic limits.** The limits in the German ordinance are those of the 1984 directive.9 Whether lower EU limits have since been adopted was not established from the sources opened for this entry.\n- **Particles from cup linings.** The two paper-cup studies counted different size ranges with different methods.12,13 Their results cannot be compared directly, and exposure from drinking was not assessed.\n\n## Key studies\n\n
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Carvalho & Spence, 2018 – Cup shape and specialty coffee. At a specialty coffee event in Brazil, 276 professionals and experienced consumers each tasted one pour-over coffee from a tulip, open or split ceramic cup. The tulip cup gave higher aroma ratings; the split cup gave higher sweetness and acidity but lower liking, mainly among consumers.

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Food Quality and Preference 68, 315–321 · doi:10.1016/j.foodqual.2018.04.003

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Bourdon et al., 2017 – Scald injuries and cooling. A review on scald burns that tabulates the cooling of 237 and 473 mL drinks served at 70–95 °C, with and without a protective cap. A cap and a larger volume both kept the drinks hotter for longer.

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World Journal of Dermatology 6(2), 17–26 · doi:10.5314/wjd.v6.i2.17

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Abraham et al., 2016 – Predicting scalds from beverage spills. Cooling experiments varied drink volume, starting temperature, cooling time, cup material, a cap and a corrugated paper sleeve, and fed a model of burn depth. The cap, the volume and the cooling time had the largest effect on drink temperature.

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International Journal of Hyperthermia 32(8), 900–910 · doi:10.1080/02656736.2016.1211752

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BfR, 2020 – Melamine resin and bambooware. The German risk assessment institute evaluated migration tests on melamine formaldehyde resin tableware, including coffee-to-go cups with bamboo filler. About a quarter of bambooware articles released exceptionally high levels of formaldehyde, and the institute advises against hot food and drinks from this material.

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BfR Opinion No 046/2019, 25 November 2020 · bfr.bund.de

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Zangmeister et al., 2022 – Nanoparticles from single-use products. Scientists at the US National Institute of Standards and Technology measured particles released into water by single-use products, including hot beverage cups lined with low-density polyethylene. The cups released more than 10¹² particles per litre, mostly 30–80 nm across, with release depending on water temperature.

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Environmental Science & Technology 56(9) · doi:10.1021/acs.est.1c06768

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