Topic hub — 2026-10-20
Is green tea less bitter brewed cooler or cold?
Green tea is often said to taste less bitter brewed with cooler water, and even less when cold-brewed. What do studies in which people tasted tea brewed at different temperatures say? We keep bitterness and astringency apart here, because they are easy to confuse. This page lines up the included studies together with their conditions: the tea, water temperature and time, amounts of leaf and water, and who rated it on what scale. It then separates what was established within one experiment, what differences between studies might explain, and what this comparison alone cannot separate.
On this page (10 sections)
- What this page establishes
- What the included studies allow us to say
- Bitterness ratings at a glance
- Conditions and results, study by study
- What was established within an experiment
- Candidate explanations for the differences
- What is not known — what this comparison alone cannot separate
- How studies and rows were counted
- What we looked at
- Read in the encyclopedia
What this page establishes
- That the only study found in which people scored bitterness while only the temperature changed for the same leaf used Chinese Longjing tea, and cooler water was significantly less bitter.
- That for Japanese green tea, people have confirmed it tastes less astringent with cooler water, but bitterness has not been scored at different temperatures.
- That the compounds behind bitterness (caffeine and galloylated catechins) dissolve less in cooler water, though cold brews still extract them given enough time.
- That no study held the strength of the brew constant, so "weaker brew" and "fewer bitter compounds" cannot be told apart.
What the included studies allow us to say
- Only 1 study found had people score bitterness and astringency separately while only the water temperature changed for the same leaf (a Chinese Longjing tea): bitterness at 70 °C (3.13) was significantly lower than at 100 °C (5.17). For Japanese green tea, people have confirmed that cooler water makes it taste less astringent, but no study was found that scored bitterness at different temperatures. [rows: Deng 2025 standard grade, bitterness; Kubo 2014 kabusecha, astringency]
- So it cannot be said that cooler water means no bitterness. Even at 70 °C the bitterness score was not 0, and with enough time a cold steep still extracts the compounds behind bitterness. In one study cold-brewed green tea was often described as bitter (per the lab ledger). [rows: Deng 2025 standard grade, bitterness; Horie 2001 caffeine (teapot, 2 min); Orita 2023 total catechins, long cold steep; Liu 2021 cold brew still bitter]
Bitterness ratings at a glance
Only the results in which people rated bitterness. Values for "Cooler or cold" and "Hotter" are as reported. "Direction" is the larger of the two values; gaps the paper does not treat as a difference are shown as "about the same". Select a study name to jump to its detailed table.
Results in which people rated bitterness only. Values are as reported; scales and methods differ between studies, so compare within a row, not across rows.
| Study | Condition | Measured as | Cooler or cold | Hotter | Direction / test |
|---|---|---|---|---|---|
| Deng 2025 | Standard grade: 70 °C vs 100 °C (both 4 min) | 0–10 scale (9 panelists) | 3.13 | 5.17 | Hotter higher Tested, significant |
| Deng 2025 | Premium grade: 70 °C vs 100 °C | 0–10 scale (9 panelists) | Not given (the text gives only the rise) | 33% higher than at 70 °C | Hotter higher No test of the difference |
| Yoneda 1994 | Cold-brew sencha (2 °C) vs sencha (80 °C); different products; mean over 0.5–4 min, infusion 1 | mean on −2 to +2 (15 people) | −1.73 | 0.53 | Hotter higher No test of the difference |
| Liu 2021 | Cold-brewed Biluochun vs the mean of 6 cold-brewed oolong and black teas | selection rate (63 consumers) | bitterness chosen more often, lasting to the end | lower | Cooler or cold higher No test of the difference |
Conditions and results, study by study
For each study, the conditions for the tea, water temperature and time, and the rating, and the results. Each row is one study × one measured result, so bitterness, astringency and compounds are separate rows. Under each row we give where it is in the paper and whether it can be used to judge whether cooler water lowers bitterness, with the reason. Nothing is left blank: "not given", "not read" and "not applicable" are kept apart.
Deng 2025 sensory only
Elucidating the effect of brewing temperature on the sensory quality of Longjing tea based on multi-scale molecular sensory science. Food Chemistry: X 28:102635 — doi:10.1016/j.fochx.2025.102635
- How deeply checked
- Checked in full text — Read in the full text on Europe PMC (Sections 2.2, 3.1, 3.2.1); the Figure 1 image was not viewed
- Samples
- Longjing tea (Chinese pan-fired green tea), a premium and a standard grade
- Roasting
- Not applicable (processing was not compared)
- Brewing
- 70, 80, 90 and 100 °C water for 4 min, one infusion; amounts of leaf and water not given; tasted at 45 °C
- Who rated, on what scale
- 9 trained panelists; 0–10 scale; ANOVA with Duncan's test
| Measured | Condition | Cooler or cold | Hotter | Unit | Direction / test |
|---|---|---|---|---|---|
| Bitterness intensity (sensory) | Standard grade: 70 °C vs 100 °C (both 4 min) | 3.13 | 5.17 | 0–10 scale (9 panelists) | Hotter higher Tested, significant |
| Significantly higher (p < 0.05); values at 80 and 90 °C are in the figure only Where: Section 3.1 (Figure 1B) For whether cooler water lowers bitterness: Usable — Same leaf and time with only temperature changed; trained panelists scored bitterness and astringency separately, with a test; but one Longjing tea, not a Japanese steamed green tea | |||||
| Astringency (sensory) | Standard grade: 70 °C vs 100 °C | 2.07 | 4.13 | 0–10 scale (9 panelists) | Hotter higher Tested, significant |
| Significantly higher (p < 0.05) Where: Section 3.1 (Figure 1B) For whether cooler water lowers bitterness: Not usable — Astringency, not bitterness (the same study measured bitterness separately) | |||||
| Bitterness intensity (sensory) | Premium grade: 70 °C vs 100 °C | Not given (the text gives only the rise) | 33% higher than at 70 °C | 0–10 scale (9 panelists) | Hotter higher No test of the difference |
| Whether the premium-grade difference was significant is not stated in the text (the figure was not read) Where: Section 3.2.1 For whether cooler water lowers bitterness: Limited — Only the rise is given, with no statement of significance | |||||
Kubo 2014 sensory + composition
異なる条件で浸出した緑茶の渋味およびうま味の味覚センサーによる評価 (Evaluation of Astringency and Umami of Green Tea Infusions with Different Elution Conditions Using a Taste Sensor System). 日本食品科学工学会誌 (Nippon Shokuhin Kagaku Kogaku Kaishi) 61(5):192-198 — doi:10.3136/nskkk.61.192
- How deeply checked
- Checked in full text — Read in the full text of the J-STAGE PDF (Method 4, Figure 5, Table 4); astringency values are approximate readings from the figure
- Samples
- Kabusecha (shaded tea, Yabukita from Mie; a top grade and a second flush)
- Roasting
- Not applicable
- Brewing
- 25 g leaf in 1 L, left to stand; 90, 50 and 20 °C for 5 min, 5 °C alone for 30 min; components were analysed in separate brews of 2 g leaf in 200 mL
- Who rated, on what scale
- 22 people from the tea trade and others; 5-point scale (−2 to +2) against the 50 °C brew as 0; only astringency and umami were rated, not bitterness; no test of differences between conditions (the astringency–component correlation was tested)
| Measured | Condition | Cooler or cold | Hotter | Unit | Direction / test |
|---|---|---|---|---|---|
| Astringency (sensory) | 20 °C for 5 min vs 90 °C for 5 min (relative to the 50 °C brew as 0) | about −1.1 | about +1.6 | 5-point scale, −2 to +2 (22 people) | Hotter higher No test of the difference |
| No test between conditions; 5 °C for 30 min was about −1.0; bitterness was not rated Where: Figure 5, pp. 195–196 For whether cooler water lowers bitterness: Not usable — Bitterness was not rated; astringency only | |||||
| Catechins and tannin | 20 °C for 5 min vs 90 °C for 5 min | 0.11 | 0.73 | mM | Hotter higher No test of the difference |
| 0.11 and 0.73 are from separate analysis brews (2 g in 200 mL), not the tasting brews. The r² = 0.94 between astringency and the log of galloylated catechins uses 5 points: 4 conditions of kabusecha B plus kabusecha C at 50 °C Where: Table 4 For whether cooler water lowers bitterness: Not usable — Compound amount, not perceived bitterness | |||||
Yoneda 1994 sensory + composition
各種製茶の煎出条件とカフェイン・タンニン溶出量及び味との関係. 調理科学 27(1):31-38 — doi:10.11402/cookeryscience1968.27.1_31
- How deeply checked
- Checked in full text — Read in the full text of the J-STAGE PDF (Methods; Tables 1, 5, 6 and 7)
- Samples
- Commercial Uji tea from Kyoto; the cold-brew sencha and the ordinary sencha are different products
- Roasting
- Not applicable
- Brewing
- Both 3 g leaf in 80 mL for 0.5–4 min; cold brew at 2 °C, sencha at 80 °C; up to 3 infusions
- Who rated, on what scale
- 15 people rated bitterness, astringency and others on −2 to +2; no test of differences between sensory means (components were analysed by ANOVA and bitterness–component correlations were tested); each tea was rated on its own; caffeine by HPLC
| Measured | Condition | Cooler or cold | Hotter | Unit | Direction / test |
|---|---|---|---|---|---|
| Bitterness intensity (sensory) | Cold-brew sencha (2 °C) vs sencha (80 °C); different products; mean over 0.5–4 min, infusion 1 | −1.73 | 0.53 | mean on −2 to +2 (15 people) | Hotter higher No test of the difference |
| No test of differences between sensory means; in sencha bitterness correlated with caffeine concentration (r = 0.700, 1% level) but not significantly with tannin (r = 0.498) Where: Tables 5, 6 and 7 For whether cooler water lowers bitterness: Limited — People rated bitterness; but the cold brew and sencha are different products, the cold brew was only 0.5–4 min at 2 °C, and there is no test | |||||
| Astringency (sensory) | Cold-brew sencha (2 °C) vs sencha (80 °C); different products; mean over 0.5–4 min, infusion 1 | −1.67 | 0.66 | mean on −2 to +2 (15 people) | Hotter higher No test of the difference |
| No test of differences between sensory means Where: Table 5 For whether cooler water lowers bitterness: Not usable — Astringency, not bitterness | |||||
| Caffeine | Cold-brew sencha (2 °C) vs sencha (80 °C), infusion 1, 2 min | 2.53 | 31.96 | mg per 80 mL | Hotter higher No test of the difference |
| Different products; no test Where: Table 1 For whether cooler water lowers bitterness: Not usable — Compound amount | |||||
Liu 2021 sensory only
Evaluation of Sensory Quality for Taiwanese Specialty Teas with Cold Infusion Using CATA and Temporal CATA by Taiwanese Consumers. Foods 10(10):2344 — doi:10.3390/foods10102344
- How deeply checked
- Checked in full text — Per the lab ledger's full-text record (not re-read for this question)
- Samples
- Taiwanese Biluochun (green tea) with 5 oolongs and 1 black tea
- Roasting
- Not applicable
- Brewing
- All cold-brewed (4–5 °C, 6 hours)
- Who rated, on what scale
- 63 consumers; temporal check-all-that-apply (TCATA), not intensity scores
| Measured | Condition | Cooler or cold | Hotter | Unit | Direction / test |
|---|---|---|---|---|---|
| Bitterness dominance (sensory) | Cold-brewed Biluochun vs the mean of 6 cold-brewed oolong and black teas | bitterness chosen more often, lasting to the end | lower | selection rate (63 consumers) | Cooler or cold higher No test of the difference |
| Not a comparison with hot water Where: Results (TCATA) For whether cooler water lowers bitterness: Not usable — Not compared with hot water; listed as an example of cold brew still tasting bitter | |||||
Horie 2001 composition only
茶主要成分の茶浸出液への溶出特性. 茶業研究報告 91:29-33 — doi:10.5979/cha.2001.91_29
- How deeply checked
- Checked in full text — Read in the full text of the J-STAGE PDF (Table 2, Figure 1)
- Samples
- Aracha (crude tea) from first- and second-flush Yabukita (2000, Kanaya, Shizuoka)
- Roasting
- Not applicable
- Brewing
- 3 g in a teapot with 200 mL at 20, 50, 70 or 90 °C for 2 min; separately, 1 g of first flush stirred in 500 mL held at 20, 60 or 90 °C for 30 s to 20 min
- Who rated, on what scale
- Not applicable (component analysis; only a note that the 20 and 50 °C brews tasted too thin)
| Measured | Condition | Cooler or cold | Hotter | Unit | Direction / test |
|---|---|---|---|---|---|
| Catechins and tannin | First flush: 20 °C vs 90 °C (teapot, 2 min) | 21 | 377 | mg/L | Hotter higher No test of the difference |
| EGCG and ECG had the lowest extraction at every temperature and barely dissolved at 20 °C Where: Table 2, Figure 1 For whether cooler water lowers bitterness: Not usable — Compound amount | |||||
| Caffeine | First flush: 20 °C vs 90 °C (teapot, 2 min) | 35 | 239 | mg/L | Hotter higher No test of the difference |
| In a separate experiment (1 g of first flush stirred in 500 mL held at 20 °C), more than 70% of the leaf's caffeine dissolved within 20 min Where: Table 2, Experiment 2 For whether cooler water lowers bitterness: Not usable — Compound amount | |||||
Ikeda 1972 composition only
煎茶の浸出条件と可溶成分との関係 (Relation between Infusing Condition of Green Tea and Soluble Component). 茶業研究報告 (Chagyo Kenkyu Hokoku, Tea Research Journal) 37:69-78 — doi:10.5979/cha.1972.69
- How deeply checked
- Checked in full text — Read in the full text of the J-STAGE PDF (Tables 5 and 6)
- Samples
- Top-grade (first flush) and ordinary-grade (refined second and third flush) sencha
- Roasting
- Not applicable
- Brewing
- 6 g leaf in 180 mL at 40, 60, 80 or 95 °C for 2–10 min (held at temperature in a 500 mL flask)
- Who rated, on what scale
- Not applicable (component analysis; no human tasting)
| Measured | Condition | Cooler or cold | Hotter | Unit | Direction / test |
|---|---|---|---|---|---|
| Catechins and tannin | Top-grade sencha: 40 °C vs 95 °C (2 min) | 1.63 | 8.39 | % of leaf weight | Hotter higher No test of the difference |
| No human tasting; from the amounts, the authors recommend brewing at around 60 °C Where: Table 5 For whether cooler water lowers bitterness: Not usable — Compound amount | |||||
Monobe 2012 composition only
緑茶冷水（4℃）浸出液のカテキン浸出特性及び茶期・品種の異なる緑茶冷水浸出液がマクロファージ様細胞の貪食能へ与える影響. 茶業研究報告 114:29-36 — doi:10.5979/cha.2012.114_29
- How deeply checked
- Checked in full text — Read in the full text of the J-STAGE PDF (Figure 1); values are the text's wording and approximate readings from the figure
- Samples
- Green tea including Yabukita (powdered leaf)
- Roasting
- Not applicable
- Brewing
- 0.75 g leaf in 30 mL; 4 °C for 60 min or 100 °C for 5 min
- Who rated, on what scale
- Not applicable (component analysis; no human tasting; Figure 1A–B used here is powdered leaf picked in April, June and August, measured once each)
| Measured | Condition | Cooler or cold | Hotter | Unit | Direction / test |
|---|---|---|---|---|---|
| Catechins and tannin | 4 °C for 60 min vs 100 °C for 5 min | about half of hot (the text's wording; about 20–45% from the figure) | reference | mg/100 mL | Hotter higher No test of the difference |
| EGC was about the same cold and hot, so the cold brew has a higher share of EGC Where: Figure 1 For whether cooler water lowers bitterness: Not usable — Compound amount (single measurement) | |||||
Orita 2023 composition only
Extraction Efficiency and Alpha-Glucosidase Inhibitory Activities of Green Tea Catechins by Different Infusion Methods. Foods 12(13):2611 — doi:10.3390/foods12132611
- How deeply checked
- Checked in full text — Read in the full text on PMC (Methods, Section 3.1)
- Samples
- 12 first-flush aracha samples from Kagoshima
- Roasting
- Not applicable
- Brewing
- 1.0 g in 50 mL; 90 °C for 90 s (hand-stirred for the first 10 s) or 25 °C for 24 h with stirring
- Who rated, on what scale
- Not applicable (component analysis; no human tasting)
| Measured | Condition | Cooler or cold | Hotter | Unit | Direction / test |
|---|---|---|---|---|---|
| Catechins and tannin | 25 °C for 24 h vs 90 °C for 90 s | 4.36 | 2.97 | g/100 g dry leaf | Cooler or cold higher Tested, significant |
| Significant in Table 3 (p < 0.05); for galloylated catechins alone, 1.57 vs 1.36, no significant difference was shown; the standard deviations differ between the text and Table 3 Where: Table 3, Section 3.1 For whether cooler water lowers bitterness: Not usable — Compound amount | |||||
What was established within an experiment
Only results where the same panel compared changed conditions within one study.
- For the standard grade of Longjing tea, going from 70 °C to 100 °C raised bitterness from 3.13 to 5.17 and astringency from 2.07 to 4.13, both significantly (9 trained panelists, 0–10 scale, 4 min). For the premium grade bitterness rose by 33%, but the text does not say whether that was significant. [rows: Deng 2025 standard grade, bitterness; Deng 2025 standard grade, astringency; Deng 2025 premium grade, bitterness]
- For kabusecha, against the 50 °C brew, astringency was about −1.1 at 20 °C and about +1.6 at 90 °C (22 people; no test of differences between conditions). Astringency ratings tracked the galloylated catechin concentration in separately brewed analysis samples (0.11 mM at 20 °C, 0.73 mM at 90 °C). Bitterness was not rated. [rows: Kubo 2014 kabusecha, astringency; Kubo 2014 kabusecha, galloylated catechins]
- Brewing the same leaf in a teapot for 2 min gave EGCG of 21 mg/L at 20 °C and 377 mg/L at 90 °C, and caffeine of 35 and 239 mg/L. In a separate experiment, stirring in water held at 20 °C dissolved more than 70% of the leaf's caffeine within 20 min. [rows: Horie 2001 EGCG (teapot, 2 min); Horie 2001 caffeine (teapot, 2 min)]
- In cold water (4 °C, 60 min) the brew had about half the EGCG of hot water (100 °C, 5 min) (about 20–45% from the figure), while EGC was about the same, so the cold brew has a higher share of EGC. [rows: Monobe 2012 EGCG (cold vs hot)]
- A long cold steep (25 °C, 24 h) significantly exceeded a short hot brew (90 °C, 90 s) in total catechins (4.36 vs 2.97 g/100 g); for galloylated catechins alone no significant difference was shown (1.57 vs 1.36). [rows: Orita 2023 total catechins, long cold steep]
Candidate explanations for the differences
Conditions that differ between studies, or between temperatures, and could explain differences in bitterness. Several conditions differ at once, so which one mattered is unknown. These are candidates, not causes.
- Caffeine. In Japanese sencha, bitterness scores correlated with caffeine concentration (r = 0.700) but not significantly with tannin. Cooler water also extracts less caffeine, making it a candidate reason for lower bitterness. [rows: Yoneda 1994 cold brew, bitterness; Horie 2001 caffeine (teapot, 2 min)]
- Galloylated catechins (EGCG and others). They dissolve especially poorly in cool water and tracked astringency ratings. How much they contribute to bitterness was not separated in the human ratings examined here. [rows: Horie 2001 EGCG (teapot, 2 min); Kubo 2014 kabusecha, galloylated catechins]
- Dilution. None of the tasting studies examined here held the strength of the brew constant, so whether cooler water lowered bitterness because the brew was weaker overall or because bitter compounds dropped selectively is unknown. In the study comparing a 0.5–4 min cold brew, caffeine was very low (2.53 vs 31.96 mg at 2 min, infusion 1); overall brew strength was not measured. [rows: Yoneda 1994 cold brew, caffeine; Yoneda 1994 cold brew, bitterness; Deng 2025 standard grade, bitterness]
What is not known — what this comparison alone cannot separate
- Human bitterness scores for Japanese steamed green tea at different temperatures: the sources found offer only astringency and umami ratings, or comparisons between different products. [rows: Kubo 2014 kabusecha, astringency; Yoneda 1994 cold brew, bitterness]
- The effect of temperature versus that of tea type and processing: the only temperature study scoring bitterness used Longjing tea, so whether the same size of effect applies to Japanese sencha is unknown. [rows: Deng 2025 standard grade, bitterness]
- Time versus temperature: cold-brew results also depend on time (even at 20 °C most caffeine dissolved within 20 min of stirring, and a 24 h cold steep exceeded a short hot brew in total catechins), so they are hard to separate from the effect of temperature alone. [rows: Horie 2001 caffeine (teapot, 2 min); Orita 2023 total catechins, long cold steep]
How studies and rows were counted
The number of evidence rows is not the number of studies. Table rows, ledger evidence rows, papers and research groups are counted separately.
- Sources in the table: 8, of which 3 had people rate bitterness; the others measured something else (compounds, smell) or are used only for context.
- Rows in the table (study × measured result): 14. Rows on perceived bitterness: 4.
- Evidence rows in the lab's ledger these rows rest on: 5. One paper can supply several rows. Rows without a ledger evidence row come from other tables of the same papers, or from sources newly read for this question.
- Independent research groups among the sensory studies: 3 (reports from the same lab count as 1).
What we looked at
The sources examined for this question, why each was included or excluded, and which full texts could not be reached. We searched PubMed, Europe PMC, J-STAGE and CiNii for studies on green tea brewing temperature, cold brewing and steeping time in relation to bitterness, astringency, catechins and caffeine, and added the sources already in the lab's ledger.
| Source | Decision | Why |
|---|---|---|
| Elucidating the effect of brewing temperature on the sensory quality of Longjing tea based on multi-scale molecular sensory science (2025) doi | Included in the table | Same leaf with only temperature changed; people rated bitterness and astringency separately, with a test; read in full |
| 異なる条件で浸出した緑茶の渋味およびうま味の味覚センサーによる評価 (Evaluation of Astringency and Umami of Green Tea Infusions with Different Elution Conditions Using a Taste Sensor System) (2014) doi | Included in the table | People rated astringency of kabusecha at different temperatures; bitterness not rated; read in full |
| 各種製茶の煎出条件とカフェイン・タンニン溶出量及び味との関係 (1994) doi | Included in the table | People rated cold-brew (2 °C) and sencha (80 °C) each on its own; different products and a short cold brew; read in full |
| Evaluation of Sensory Quality for Taiwanese Specialty Teas with Cold Infusion Using CATA and Temporal CATA by Taiwanese Consumers (2021) doi | Included in the table | As an example of cold-brewed green tea still described as bitter; not compared with hot water |
| 茶主要成分の茶浸出液への溶出特性 (2001) doi | Included in the table | Measured extraction of EGCG, caffeine and others from the same leaf at different temperatures; read in full |
| 煎茶の浸出条件と可溶成分との関係 (Relation between Infusing Condition of Green Tea and Soluble Component) (1972) doi | Included in the table | Measured tannin, EGCG and caffeine across temperatures and times; read in full |
| 緑茶冷水（4℃）浸出液のカテキン浸出特性及び茶期・品種の異なる緑茶冷水浸出液がマクロファージ様細胞の貪食能へ与える影響 (2012) doi | Included in the table | Compared EGCG and EGC in cold and hot water; read in full |
| Extraction Efficiency and Alpha-Glucosidase Inhibitory Activities of Green Tea Catechins by Different Infusion Methods (2023) doi | Included in the table | Compared catechins from a long cold steep and a short hot brew; read in full |
| Effect on the epigallocatechin gallate/epigallocatechin ratio in a green tea (Camellia sinensis L.) extract of different extraction temperatures and its effect on IgA production in mice (2010) doi | Excluded | A report from the same group showing the same trend; the 2012 report was used as representative (the 2010 report compared 4–40 °C at 60 min and 50–100 °C at 2 min, averaging 3–6 runs) |
| ‘やぶきた’二番茶の煎茶および釜炒り茶の冷水浸出液における化学成分の違い (2023) doi | Excluded | Cold water only, with no hot-water comparison and no human rating |
| Relation between Lixiviation Condition of Tea and Soluble Component. (1964) doi | Excluded | The human assessment was an overall quality judgement (taste best at 100 °C), not bitterness intensity |
| 茶の淹れ方による呈味の味認識装置による評価 (2013) doi | Excluded | Mainly a taste-sensor study with no bitterness values reported (human ratings compared only umami and astringency); times not matched (5 °C alone for 10 min) |
| 水だし煎茶における浸出時間と嗜好性および溶出成分量との関係 (1999) doi | Excluded | Preference rankings over cold-brew times, with no bitterness intensity and no hot comparison |
| Effects of different brewing conditions on catechin content and sensory acceptance in Turkish green tea infusions (2015) doi | Excluded | Acceptance scores, not bitterness intensity (the full text was blocked by a verification page this time) |
| Effects of different types of water on the sensory and physicochemical properties of cold-brewed green tea (2026) doi | Excluded | Compares water types, not temperatures |
| Revealing the influence of top-brewing and bottom-brewing methods on the flavor of green tea based on the interaction between EGCG and aroma compounds (2026) doi | Excluded | Compares the order of adding water and leaf; human rating at 85 °C only |
| Optimization of brewing conditions for Tieguanyin oolong tea by quadratic orthogonal regression design (2022) doi | Excluded | Oolong tea, with bitterness and astringency rated as a single attribute |
| 苦味が煎茶の濃さに及ぼす影響（ほか同じグループの大会要旨） (2019) doi | Excluded | Conference abstracts that do not give bitterness results for each brewing method |
| Influence of steeping conditions (time, temperature, and particle size) on antioxidant properties and sensory attributes of some white and green teas. (2015) doi | Full text not reachable | The abstract gives no bitterness values by temperature; full text subscription-only |
| The chemical basis of aroma/taste and color formation in green tea infusion during cold brewing revealed by metabolomics analysis. (2025) doi | Full text not reachable | Compares cold brew with 80 °C; the abstract does not show whether bitterness was rated by people; full text subscription-only |
| Effects of alternative steeping methods on composition, antioxidant property and colour of green, black and oolong tea infusions (2015) doi | Full text not reachable | Composition and colour study; full text blocked by a verification page |
Read in the encyclopedia
- Green tea — the drink in this question
- Caffeine — the compound that tracked bitterness scores in sencha
- Epigallocatechin gallate (EGCG) — a galloylated catechin that dissolves poorly in cool water
- Tea catechins — candidates behind astringency and bitterness
- Tea bitterness — the topic hub on tea's bitter and astringent compounds and brewing
Source ledger
Each study's source can be reached from its section above. All of the lab's sources are listed in thesource ledger.
How to cite this page
Aoki, M. (NIGAMI LAB) (2026). Is green tea less bitter brewed cooler or cold?. https://nigamilab.com/en/topics/green-tea-temperature/
Each claim card has a stable anchor (#clm-…). The dataset is CC BY 4.0; see the data page. Dataset DOI: 10.5281/zenodo.22739101