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Extraction · Fundamental

Brew temperature

How hot the water is when it meets the coffee – the ranges that standards specify, what heat does to the speed and end point of extraction, where heat is lost, and why water boils below 100 °C at altitude.

Across the chain: Science

Source-checkedby Coffearium verification pass· Last source-checked 20 Oct 2026· Prepared with AI assistance· 15 sources (10 tier A)· 3 contested· Updated 20 Oct 2026
Reading depth
Contents
  • The Specialty Coffee Association (SCA) home-brewer standard specifies the slurry, not the kettle – 90–96 °C from the time a third of the water is in.4
  • Hotter water extracts faster. In one immersion study, a 99 °C brew passed 4% TDS within 20 min; 94 and 80 °C brews took over 30 min.2
  • In full immersion, the final strength did not change between 80 and 99 °C; brews started at 92 °C did extract more than cold brews.2,3
  • Drip brews made at 87, 90 and 93 °C to the same strength and extraction yield showed no appreciable sensory difference in one 2020 study.1
  • Water boils below 100 °C at altitude – near 93.5 °C at about 2,000 m (our calculation from published steam tables and a standard atmosphere).13,14

What brew temperature means#

Brew temperature is how hot the water is while it extracts the coffee. The number depends on where it is measured. A kettle or heater has a set point. The slurry – the wet mix of coffee and water in the brewer – can be cooler.2,10

Standards therefore say where they measure. The Specialty Coffee Association (SCA) home-brewer standard measures the slurry in the basket.4 An Italian espresso specification places its probe about 1 mm from the shower screen, where water leaves the group.6 The SCA cupping standard specifies the water as it is poured.5

Brew temperature is not drinking temperature; the serving temperature entry covers the cup.

What heat does to extraction#

Speed. Hotter water extracts faster. In a 2021 immersion study, a 99 °C brew passed 4% TDS (total dissolved solids) within 20 minutes.2 Brews started at 94 and 80 °C took more than 30 minutes to reach similar values.2

Why. According to a coffee science textbook, most coffee compounds dissolve better in hotter water.11 Hot water is also less viscous, so it enters the bed and the particles more easily.11 In the textbook’s account, the effect differs between compounds. High temperatures favour the extraction of less polar compounds, and bitter, astringent and phenolic compounds gain the most.11

End point. Speed and end point are different things. In the 2021 study, full immersion brews between 80 and 99 °C settled at about the same final strength.2 Much colder water did change the end point. In a 2022 study, brews started at 92 °C extracted on average about 13% more soluble material than brews at 4 °C.3 The extraction yield entry explains how strength and yield are calculated.

Flavour. A 2020 study brewed drip coffee at 87, 90 and 93 °C.1 It varied brew time, flow rate, dose and grind size so that every temperature hit the same strength and yield.1 Trained panellists then found no appreciable sensory effect of temperature.1 Strength and yield shaped the cup; temperature mainly changed how fast the brew got there.1

Ranges in standards#

Several documents specify a temperature window. Each is written for its own purpose, and each measures at a different point.

  • Home brewers. SCA 310-2021 requires the slurry to reach 90–96 °C by the time 33% of the water has been sprayed.4 It must stay in that range to the end of the brew cycle.4
  • Earlier SCA documents. A 2020 study reports 92–96 °C from the Coffee Brewing Handbook (2011) and from the SCA home-brewer programme of 2017.1
  • Cupping. SCA 102-2024 specifies water at 93 ± 3 °C, poured onto the grounds to the rim.5
  • Espresso. An Italian specification published with the contact details of the Comitato Italiano del Caffè (COMITCAF) sets 90–96 °C.6 The Italian Espresso National Institute (INEI) is reported with 90 ± 2 °C for water leaving the machine.7
8486889092949698100°CSCA 310-2021 · slurry,home brewers90–964 SCA home-brewer programme2017 · as reported92–961 Coffee Brewing Handbook2011 · as reported92–961 SCA 102-2024 · cuppingwater93 ± 35 COMITCAF · espresso, atshower screen90–966 INEI · espresso, leavingmachine, as reported90 ± 27
Data table
°CSource
SCA 310-2021 · slurry, home brewers90–964
SCA home-brewer programme 2017 · as reported92–961
Coffee Brewing Handbook 2011 · as reported92–961
SCA 102-2024 · cupping water93 ± 35
COMITCAF · espresso, at shower screen90–966
INEI · espresso, leaving machine, as reported90 ± 27
Brewing temperature windows as specified or reported for each document; each row is a specification, not a measured effect. Measuring points differ: slurry, poured water, or water at the shower screen.1,4,5,6,7

SCA 310-2021 also limits the holding plate. A heated carafe must keep the coffee at 80–85 °C for the first 30 minutes and never heat it above 85 °C.4

Where the heat goes#

Heat is lost between the heater and the coffee. In the 2021 immersion study, the beaker had no lid or insulation. The temperature fell after the hot water was added to the room-temperature grounds.2

Machines show the same gap. In a 2023 espresso study, set points of 80, 89 and 98 °C gave average brew temperatures of 79.1, 88.2 and 96.5 °C.9 The machine measured them just above the coffee puck.9 A 2009 study of espresso pods found measured temperatures significantly below the controller settings.10

The heating system shapes the curve over a shot. In a 2013 comparison, temperature on the coffee filter peaked at 93 °C in a pump machine and 98 °C in a lever machine.7 In the lever machine it then fell about 10 degrees during extraction.7 The pump machine extracted more chlorogenic acids; the authors judged this very likely due to its lower temperature and found pressure less influential.7 The two machines also differed in their pressure curves7, so the comparison does not isolate temperature. The espresso machine entry explains boilers, heat exchangers and temperature control.

For hand brewing, no peer-reviewed measurement of the slurry in a pour-over dripper was found among the sources opened for this entry. Figures that circulate for kettle-to-slurry losses are therefore left out.

Boiling point and altitude#

Water boils when its vapour pressure equals the pressure of the air above it. The SCA water handbook explains the lower boiling point at high altitude this way.12 Air pressure falls with height, so an open kettle reaches a lower maximum temperature in the mountains.12,14

The figures below are our own calculation. They combine steam tables published by the US National Institute of Standards and Technology (NIST) with a NASA standard-atmosphere model.13,14 At about 1,000 m, water boils near 96.7 °C. At about 2,000 m, it boils near 93.5 °C, and at about 3,000 m near 89.9 °C. The US Department of Agriculture gives a similar rule: just under 1 °F less per 500 feet of height.15

010002000300040005000600080859095100Altitude in the standard atmosphere (m, our calculation)Boiling point (°C)Pure water13
Data table
SeriesAltitude in the standard atmosphere (m, our calculation)Boiling point (°C)Source
Pure water12099.60613
Pure water55098.17813
Pure water100096.68713
Pure water147095.12513
Pure water196093.48613
Pure water248091.75813
Pure water302089.93213
Pure water360087.99313
Pure water422085.92613
Pure water488083.70913
Pure water559081.31713
Boiling point of water against altitude. Each point is a saturation temperature from the IAPWS-95 steam tables13, placed at the altitude where a standard atmosphere has that pressure.14 Altitudes are our own calculation; real air pressure varies.

Above about 3,000 m, water in an open kettle boils below 90 °C, the lower limit of SCA 310-2021 (our comparison).4,13,14 A closed boiler under pressure can exceed 100 °C, because pressure sets the boiling point.12

Cold brew: the low end#

Cold brew uses water at room temperature or in the fridge. It needs hours instead of minutes. In the 2022 study, fridge brews at 4 °C stood for 24–36 h and room-temperature brews for 12–14 h. Brews started at 92 °C needed 1–2 h.3 The cold brew entry covers the method and its flavour.

Rate and equilibrium#

Two questions are easily mixed up: how fast a brew extracts, and how much it can extract in the end.

Rate. In the 2021 immersion study, hotter water reached a steady TDS sooner.2 At a brew ratio of 5, the 99 °C brew passed 4% TDS within 20 min; the 94 and 80 °C brews took more than 30 min.2 At a brew ratio of 25, all temperatures reached about 0.7% TDS within 20 min.2 To be sure of equilibrium, the study steeped its 1 L brews for 60 min at 80 °C, 45 min at 85 °C, 30 min at 94 °C and 20 min at 99 °C.2

0102030405060min80 °C start60 min2 85 °C start45 min2 94 °C start30 min2 99 °C start20 min2
Data table
minSource
80 °C start60 min2
85 °C start45 min2
94 °C start30 min2
99 °C start20 min2
Steeping times one immersion study allowed for its 1 L brews to reach equilibrium, by starting water temperature. They are chosen times, not measured end points; the brews stood on a countertop at room temperature.2

Equilibrium. In the same study, the final TDS did not change appreciably with brew temperature. At a brew ratio of 5 it was 4.07 ± 0.15%, and at 25 it was 0.75 ± 0.04%, over 80–99 °C.2 The partition constant K, which describes how solids divide between grounds and liquid, did not change appreciably either.2 The authors call this insensitivity to temperature surprising.2

Cold water behaves differently. In the 2022 study at a brew ratio of 5, equilibrium extraction averaged 22.28% for brews started at 92 °C, 20.74% at 22 °C and 19.55% at 4 °C.3 The average TDS was 4.27%, 3.98% and 3.76%.3 Over three coffees and three roast degrees, extraction ranged from about 21.2–23.3% hot to about 17.9–21.2% at 4 °C.3 The 92 °C brews were left to cool without further heating.3

Kinetics. According to a coffee science textbook, hotter water molecules have more kinetic energy and mobility, and lower viscosity eases penetration into the particles.11 The textbook also states that solubility rises with temperature, but not linearly and not equally for every compound.11 In its account, caffeine solubility rises much more steeply than that of citric acid, so the balance between them can shift with temperature.11 No study opened for this entry fitted an activation energy for coffee extraction; the 2021 study reports no values for its rate constants and no temperature dependence for them.2

Sensory evidence#

Drip. The 2020 study used a commercial drip brewer programmed to 87, 90 or 93 °C.1 Brew time, flow rate, dose and grind size were varied to reach nine target points on the brewing control chart at each temperature.1 TDS and extraction yield changed the sensory profile significantly; brew temperature had no appreciable effect.1 Coffee from the 87 °C brews was 4–5 °C cooler straight after brewing.1 The 2021 immersion authors point out that this drip range was narrower than their own.2

Immersion. The 2021 authors caution that equal TDS and yield do not prove equal flavour.2 They suggest that the drip result may extend to immersion, which remains untested.2 In the 2022 immersion study, every brew was diluted to 2% TDS before tasting.3 Cold brews were then rated more floral and less bitter, sour and rubbery than hot brews.3

Espresso. The evidence is mixed (see Contested).

  • An on-line aroma study brewed espresso at 82, 92 and 96 °C at 9 bar. Higher temperature significantly increased volatile compounds, mostly late in the 25 s shot, and most for the less polar ones.8 The study chose 92 °C as its centre point within recommendations of the Specialty Coffee Association of America.8
  • A 2023 flow-controlled study varied the set point from 80 to 98 °C. Higher temperature generally increased the mass of each compound in the cup. Flow rate had the strongest effect; the effects of flow rate, grind and temperature were small compared with those of brew ratio.9
  • The same 2023 study summarises earlier work. One study found no significant difference in trigonelline, caffeine and chlorogenic acids at 75, 80 or 85 °C; another reported ambiguous correlations at 88, 92, 96 and 98 °C.9 A third described different influences on caffeine and 5-CQA for upward and downward temperature gradients between 88 and 93 °C, without a conclusive correlation.9
  • A 2009 pod study at set points of 90, 100 and 110 °C linked the solids and caffeine at 110 °C to over-extraction.10
  • The 2020 drip study cites espresso work in which temperature differences within 80–93 °C were imperceptible in triangle tests.1

The espresso recipes entry covers how baristas use temperature alongside dose, ratio and flow.

Measuring brew temperature#

Document or study What is measured How Source
SCA 310-2021 Slurry in the basket Three K-type thermocouples at the top and centre of the bed, floating in the slurry; one reading per second SCA4
SCA 310-2021, holding Coffee in the carafe One reading per minute for 30 min SCA4
COMITCAF specification Water leaving the group Probe about 1 mm from the shower screen, centred COMITCAF6
Schmieder et al., 2023 Brew water Machine sensor just above the puck, logged continuously Schmieder et al.9
Caprioli et al., 2013 Temperature on the coffee filter Curves over the shot Caprioli et al.7
Liang et al., 2021 Immersion brew Kettle set point; brew logged with a wireless thermometer Liang et al.2

A set point, a water temperature at the shower screen and a slurry temperature are three different numbers. Comparisons between studies need to say which one they use.

Reference values#

Parameter Value Context Source
Slurry, home brewers 90–96 °C from 33% of the water on, held to the end SCA 310-2021 SCA4
Holding plate 80–85 °C for 30 min; never above 85 °C from heating SCA 310-2021 SCA4
Test conditions Water 17 ± 3 °C; coffee, brewer and room 20 ± 3 °C SCA 310-2021 SCA4
Earlier SCA windows 92–96 °C Coffee Brewing Handbook (2011); home-brewer programme (2017), as reported Batali et al.1
Cupping water 93 ± 3 °C SCA 102-2024 SCA5
Espresso, extraction temperature 90–96 °C COMITCAF specification, probe at shower screen COMITCAF6
Espresso, water leaving machine 90 ± 2 °C INEI, as reported Caprioli et al.7
Drip temperatures tested 87, 90, 93 °C – no appreciable sensory effect at fixed TDS and yield One commercial brewer Batali et al.1
Immersion rate, ratio 5 99 °C: > 4% TDS within 20 min; 94 and 80 °C: > 30 min Uninsulated beaker Liang et al.2
Immersion equilibrium TDS 4.07 ± 0.15% (ratio 5); 0.75 ± 0.04% (ratio 25) 80–99 °C Liang et al.2
Steeping time allowed 60, 45, 30, 20 min 80, 85, 94, 99 °C Liang et al.2
Equilibrium extraction 22.28% (92 °C start); 20.74% (22 °C); 19.55% (4 °C) Ratio 5; means of three coffees at three roast degrees Batali et al.3
Espresso set vs measured 80 → 79.1 °C; 89 → 88.2 °C; 98 → 96.5 °C (SD 0.5) Flow-controlled machine Schmieder et al.9
Espresso peak on filter 93 °C (pump); 98 °C, falling about 10 degrees (lever) Two machines Caprioli et al.7
Espresso aroma study 82, 92, 96 °C at 9 bar 18 g, 25 s Sánchez López et al.8

Boiling point: the calculation#

Method (our calculation). The NIST tabulation of the IAPWS-95 formulation lists the saturation temperature of water at each pressure.13 The NASA model gives the pressure of a standard atmosphere in the troposphere as p = 101.29 × [(T + 273.1) ÷ 288.08]5.256 kPa, with T = 15.04 − 0.00649 × h in °C and h in metres.14 Solving it for h gives the altitude at which each tabulated pressure occurs.

Pressure (kPa) Boiling point (°C) Altitude in the standard atmosphere (m, our calculation)
100 99.606 ≈120
95 98.178 ≈550
90 96.687 ≈1,000
85 95.125 ≈1,470
80 93.486 ≈1,960
75 91.758 ≈2,480
70 89.932 ≈3,020
65 87.993 ≈3,600
60 85.926 ≈4,220
55 83.709 ≈4,880
50 81.317 ≈5,590

Saturation temperatures from NIST13; altitudes from the NASA model.14 The same tables give 101.42 kPa for 100 °C.13

Cross-check. Near sea level, the boiling point falls by about 3.3 °C per 1,000 m (our calculation from the table). The USDA rule of just under 1 °F per 500 feet works out at about 3.6 °C per 1,000 m (our conversion).15 The USDA also gives 208 °F at 2,000 feet and about 198 °F at 7,500 feet.15 That is 97.8 °C at 610 m and about 92.2 °C at 2,286 m (our conversion), close to the table.

Limits. The standard atmosphere is a model; the pressure on a given day differs. The steam tables describe pure water.13

Open questions#

  • Slurry temperature by hand. No peer-reviewed measurement of slurry temperature in a hand-poured dripper, or of losses from kettle to bed, was found among the sources opened for this entry.
  • Sensory effect beyond one drip brewer. The 2020 study tested 87–93 °C on one brewer.1 Whether the result holds at lower temperatures, in immersion or in espresso at fixed strength and yield is not established.2
  • Temperature dependence of rate constants. No study opened for this entry reported an activation energy or a temperature-dependent rate constant for coffee extraction as a whole.
  • Energy use. The 2020 authors suggest that lower brew temperatures could save energy, since work they cite found the brewing step to have the highest carbon footprint in the coffee supply chain.1 No study opened for this entry quantified the saving per cup.
  • Altitude in practice. No study opened for this entry compared brews made at high altitude with brews at sea level.

Key studies#

Batali et al., 2020 – Temperature at fixed strength and yield. Drip-brewed one coffee at 87, 90 and 93 °C to nine target points on the brewing control chart, varying brew time, flow rate, dose and grind size. Trained panellists found that strength and extraction yield shaped the sensory profile, while brew temperature had no appreciable effect.

Scientific Reports 10, 16450 · doi:10.1038/s41598-020-73341-4

Liang et al., 2021 – Equilibrium in immersion. Built a desorption model for full immersion and tested it at brew ratios up to 25 and temperatures of 80–99 °C. Hotter water reached a steady TDS sooner, but the final strength and the partition constant did not change appreciably with temperature.

Scientific Reports 11, 6904 · doi:10.1038/s41598-021-85787-1

Batali et al., 2022 – Cold, room and hot immersion. Brewed three coffees at three roast degrees to equilibrium at 4, 22 and 92 °C, then diluted all to 2% TDS for a trained panel. Hot water extracted about 13% more material than the coldest water, and the cold brews were more floral and less bitter and sour.

Foods 11(16), 2440 · doi:10.3390/foods11162440

Sánchez López et al., 2016 – Aroma during the shot. Followed volatile compounds in the espresso stream second by second with PTR-ToF-MS at 82, 92 and 96 °C and at 7, 9 and 11 bar. Higher temperature raised aroma extraction mainly in the second half of the shot, and most for the less polar compounds.

International Journal of Mass Spectrometry 401, 22–30 · doi:10.1016/j.ijms.2016.02.015

Schmieder et al., 2023 – Temperature among other settings. Brewed flow-controlled espresso at set points of 80, 89 and 98 °C, with measured brew temperatures slightly below each, and analysed fractions for caffeine, trigonelline, 5-CQA and TDS. Temperature generally raised the mass in the cup, but its effect was small, and flow rate mattered most.

Foods 12(15), 2871 · doi:10.3390/foods12152871

Contested
  • Recommended brewing window: the Coffee Brewing Handbook (2011) and the SCA home-brewer programme of 2017 are reported with 92–96 °C1; SCA 310-2021 specifies a slurry of 90–96 °C4; the Italian Espresso National Institute (INEI) is reported with 90 ± 2 °C leaving the machine.7 The documents measure at different points and serve different purposes.
  • Temperature and the end point of extraction: in full immersion between 80 and 99 °C, the equilibrium TDS and the partition constant did not change appreciably2; brews started at 92 °C reached on average 22.28% extraction against 20.74% at 22 °C and 19.55% at 4 °C.3 The temperature ranges differ, so both findings can hold.
  • Temperature in espresso: a 2003 study is summarised as finding that hotter water predictably increased TDS and extraction1, while a 2023 study calls the same study’s temperature correlations ambiguous and found only small effects in its own flow-controlled shots9; an on-line aroma study found a significant increase in volatile compounds from 82 to 96 °C.8
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Change log

  • – The 2020 drip study is described as varying brew time, flow rate, dose and grind size, not only grind and brew time. Reason: Verification against the paper's methods.
  • – The textbook statement on polarity now says high temperatures favour less polar compounds and that bitter, astringent and phenolic compounds gain most, instead of "most bitter ones need higher temperatures". Reason: The earlier wording was stronger than the source.
  • – The 2023 espresso study's summary of effect sizes and of the 2017 temperature-gradient study is reworded to match the paper; the 2013 machine comparison now adds the authors' attribution and that the machines also differed in pressure. Reason: Verification against the papers.

Sources

  1. ABatali, M. E.; Ristenpart, W. D.; Guinard, J.-X. (2020). Brew temperature, at fixed brew strength and extraction, has little impact on the sensory profile of drip brew coffee. Scientific Reports 10, 16450. doi:10.1038/s41598-020-73341-4 · other copies
  2. ALiang, J.; Chan, K. C.; Ristenpart, W. D. (2021). An equilibrium desorption model for the strength and extraction yield of full immersion brewed coffee. Scientific Reports 11, 6904. doi:10.1038/s41598-021-85787-1 · other copies
  3. ABatali, M. E.; Lim, L. X.; Liang, J.; Yeager, S. E.; Thompson, A. N.; Han, J.; Ristenpart, W. D.; Guinard, J.-X. (2022). Sensory Analysis of Full Immersion Coffee: Cold Brew Is More Floral, and Less Bitter, Sour, and Rubbery Than Hot Brew. Foods 11(16), 2440. doi:10.3390/foods11162440 · other copies
  4. A/BSpecialty Coffee Association (2021). SCA Standard 310-2021 Home Coffee Brewers: Specifications and Test Methods. Specialty Coffee Association (document © 2022).
  5. A/BSpecialty Coffee Association (2024). SCA Standard 102-2024 Coffee Value Assessment: Sample Preparation and Tasting Mechanics. Specialty Coffee Association.
  6. A/BIssuer not named on the document; every page carries the contact details of COMITCAF (Comitato Italiano del Caffè), Corso di Porta Nuova 34, Milan (2018). Disciplinare Caffè Espresso Italiano Tradizionale. Specification document, no version date stated (file dated 2018).
  7. ACaprioli, G.; Cortese, M.; Odello, L.; Ricciutelli, M.; Sagratini, G.; Tomassoni, G.; Torregiani, E.; Vittori, S. (2013). Importance of Espresso Coffee Machine Parameters on the Extraction of Chlorogenic Acids in a Certified Italian Espresso by Using SPE-HPLC-DAD. Journal of Food Research 2(3), 55–64. doi:10.5539/jfr.v2n3p55 · other copies
  8. ASánchez López, J. A.; Wellinger, M.; Gloess, A. N.; Zimmermann, R.; Yeretzian, C. (2016). Extraction kinetics of coffee aroma compounds using a semi-automatic machine: On-line analysis by PTR-ToF-MS. International Journal of Mass Spectrometry 401, 22–30. doi:10.1016/j.ijms.2016.02.015 · other copies
  9. ASchmieder, B. K. L.; Pannusch, V. B.; Vannieuwenhuyse, L.; Briesen, H.; Minceva, M. (2023). Influence of Flow Rate, Particle Size, and Temperature on Espresso Extraction Kinetics. Foods 12(15), 2871. doi:10.3390/foods12152871 · other copies
  10. AAlbanese, D.; Di Matteo, M.; Poiana, M.; Spagna Musso, S. (2009). Espresso coffee (EC) by POD: study of thermal profile during extraction process and influence of water temperature on chemical–physical and sensorial properties. Food Research International 42, 727–732. doi:10.1016/j.foodres.2009.02.027 · other copies
  11. BMestdagh, F.; Glabasnia, A.; Giuliano, P. (2017). The Brew – Extracting for Excellence. In: Folmer, B. (ed.), The Craft and Science of Coffee, Academic Press, ch. 15, pp. 355–380. doi:10.1016/B978-0-12-803520-7.00015-3 · other copies
  12. A/BWellinger, M.; Smrke, S.; Yeretzian, C. (2018). The SCA Water Quality Handbook, edition 2 (ISBN 978-0-9995807-3-8). Specialty Coffee Association.
  13. AHarvey, A. H. (1998). Thermodynamic Properties of Water: Tabulation from the IAPWS Formulation 1995 for the Thermodynamic Properties of Ordinary Water Substance for General and Scientific Use (NISTIR 5078). National Institute of Standards and Technology (NIST).
  14. ANASA Glenn Research Center Earth Atmosphere Model – Metric Units. National Aeronautics and Space Administration (NASA).
  15. AU.S. Department of Agriculture, Food Safety and Inspection Service (FSIS) High Altitude Cooking. U.S. Department of Agriculture.

Tier A · authoritative · B · trade and expert · C · general. Supporting quotes for every source are in the data version of this entry. If a publisher’s site refuses access, try the doi link or “other copies”.

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