Green tea infusion is an infusion prepared from leaves of Camellia sinensis.
Structured claims — open a section to read each claim's confidence, evidence and limits
Sensory (18)
green tea infusion — sensory attribute: bitternesssupported Scope: Brewed green tea
Note: Intensity depends on the tea leaf and brewing method. / 2026-08-31: Calibrated down from established to supported, because the supporting evidence does not derive from a full-text check. May be re-upgraded after a full-text check.
Positions bitterness as one of the main quality attributes of green tea, and reviews the compounds and perception involved.
Limitations: A broad review; preparation conditions vary.
The source states that bitterness and astringency are 2 important quality attributes of green tea infusion and, treating catechins as the main contributing component, builds a quantitative model of green tea infusion bitterness from concentration (bitterness correlates with EGCG + ECG at R2 = 0.7769). Supported by a primary quantitative study independent of Deng 2022 (a review).
Limitations: Only the abstract was checked. The abstract does not state the panel size or details of the evaluation method.
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ingredient-green-tea —has_sensory_attribute→ sensation-bitterclaim: clm-green-tea-bitter / type: sensory / updated: 2026-08-31
green tea infusion — sensory attribute: astringencysupported Scope: Brewed green tea
Note: Kept separate from bitterness even where the compounds driving the two overlap. / 2026-08-31: Calibrated down from established to supported, because the supporting evidence does not derive from a full-text check. May be re-upgraded after a full-text check.
Positions astringency as a main quality attribute of green tea, separate from bitterness.
Limitations: A broad review; preparation conditions vary.
In the same quantitative study, the astringency of green tea infusion correlated highly with the concentration of ECG and flavonol glycosides (myricetin 3-O-galactoside and quercetin-3-O-rutinoside) (R2 = 0.7878, p < 0.01). Supported by a primary study that treats green tea's astringency quantitatively as an attribute on a separate axis from bitterness.
Limitations: Only the abstract was checked. The abstract does not state the astringency evaluation method (scale, etc.).
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ingredient-green-tea —has_sensory_attribute→ sensation-astringentclaim: clm-green-tea-astringent / type: sensory / updated: 2026-08-31
green tea infusion — bitterness correlates with: The concentration of EGCG and ECGsupported
Scope: Green tea infusions and the concentration-taste model in the cited study
Note: The correlation and fitted curve are specific to this study and are not a universal conversion formula.
In the tested infusions, bitterness correlated strongly with EGCG and ECG concentration (reported R-squared 0.7769).
Limitations: The correlation is specific to the study's material and model.
The hTAS2R39 response was strongest for ECg, followed by EGCg, with EC and EGC far weaker. The abstract states that this response order resembles the bitterness-intensity observations from human sensory studies. This supports, from the receptor side, the sensory-side claim (Xu 2018) that green tea bitterness correlates strongly with EGCG and ECG concentration.
Limitations: Abstract-level only. The "similarity" between response order and sensory intensity is the authors' own statement, not a direct correspondence measured in the same samples.
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ingredient-green-tea —has_bitterness_correlated_with→ (the claim sentence above)claim: clm-tea-egcg-ecg-bitter / type: sensory / updated: 2026-08-30
green tea infusion — astringency correlates with: ECG and selected flavonol glycoside concentrationssupported
Scope: Green tea infusion in the cited study
Note: Interactions within the mixture and preparation conditions have an effect.
Astringency showed high correlation with ECG and particular flavonol glycosides (reported R-squared 0.7878).
Limitations: The correlation is specific to the experimental materials and model of that study.
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ingredient-green-tea —has_astringency_correlated_with→ (the claim sentence above)claim: clm-tea-ecg-flavonol-astringent / type: sensory / updated: 2026-08-30
L-theanine — perceived bitterness is associated with: green tea infusionsupported Scope: Layer: food. Green tea extracted in 3 successive infusions (GT1-GT3), five-taste sensory evaluation by electronic tongue, Pearson correlation analysis, and PLSR.
"GT1 was distinctly characterized by its pronounced bitterness and puckery, correlating strongly with elevated levels of catechins (epigallocatechin gallate, epicatechin gallate), gallic acid, caffeine, and certain amino acids (L‐theanine, L‐glutamic acid, and L‐lysine)." And: "amino acids contribute to the fresh and sweet taste of tea, playing a key role in enhancing the overall refreshing quality of tea and mitigating its bitterness."
Limitations: This is a correlational analysis, not an intervention experiment that manipulated L-theanine alone. The direction of its effect on bitterness (positive correlation vs. mitigation) is not necessarily stated consistently within the text.
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compound-l-theanine —has_perceived_bitterness_associated_with→ ingredient-green-teaclaim: clm-w71a2-theanine-correlates-first-infusion-bitterness / type: sensory / updated: 2026-09-07
green tea infusion shows the sensory response In a commercial cold-brew sencha (3 g steeped in 80 mL of 2°C water for 0.5–4 minutes, repeated up to 3 infusions), bitterness and astringency were rated weak (5-point scale from −2 to +2, averaged over all steeping times; bitterness for infusions 1–3: −1.73, −1.73, −1.87; astringency: −1.67, −1.73, −1.73). In the same report, a commercial sencha steeped at 3 g in 80 mL of 80°C water scored 0.53, 0.20, −0.87 for bitterness and 0.66, 0.54, −0.53 for astringency.supported
Scope: 1 commercial cold-brew sencha sample and 1 commercial Uji sencha sample (a different product). 15 faculty and staff members of Notre Dame Women's University rated each sample on its own on 5-point scales: bitterness, astringency, sweetness, umami and overall taste from strong +2 to weak −2, and preference from like +2 to dislike −2.
Note: The cold-brew sencha and the sencha are different commercial products, so this is not a comparison of the same leaves at different water temperatures. The authors infer that the low scores come from the small amount of extracted components. The cold-brew sencha was also somewhat weak in sweetness, umami, and overall taste. The water temperature is given as 2°C, as in the original (a low value for cold brewing).
For the cold-brew sencha, bitterness was −1.73 (1st infusion), −1.73 (2nd), and −1.87 (3rd), and astringency was −1.67, −1.73, and −1.73 (averages over all steeping times). The text states that all cold-brew sencha scores were low, that sweetness, umami, and overall taste were somewhat weak, and that bitterness and astringency were rated weak. The same table gives the sencha (80°C) values: bitterness 0.53, 0.20, −0.87 and astringency 0.66, 0.54, −0.53.
Limitations: This is not a comparison of the same leaves at different water temperatures; the cold-brew sencha and the sencha are different commercial products. The sensory scores in Table 5 are means only, with no variance or test of score differences (component amounts were analysed by ANOVA). The water temperature is given as 2°C.
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ingredient-green-tea —has_sensory_response→ (the claim sentence above)claim: clm-sencha-coldwater-weak-bitterness-astringency-yoneda-1994 / type: sensory / updated: 2026-10-21
green tea infusion — perceived bitterness is unchanged by: When 3 g of sencha was steeped in 80 mL of 80°C water for 0.5, 1, 2, 3, or 4 minutes, scores for bitterness, astringency, and the other items differed little with steeping time. In contrast, the tannin in the infusion increased with longer steeping; in the 1st infusion it was 6.69 (0.5 min), 9.46 (1 min), 18.38 (2 min), 22.23 (3 min), and 25.47 (4 min) mg/80 mL.preliminary
Scope: 1 commercial Uji sencha sample. 15 faculty and staff members of Notre Dame Women's University rated bitterness, astringency, and other items individually on a 5-point scale from −2 to +2. For both bitterness and astringency, the difference by steeping time (0.5–4 min) was reported to be small.
Note: The bitterness and astringency scores for each steeping time are not shown in the text (only the representative scores at 2 minutes), and the small difference is the authors' statement. Tannin was measured by chemical analysis (iron tartrate method) and is not equated with sensory evaluation.
For sencha, the text states that "the differences in ratings among steeping times were small in each of the 1st, 2nd, and 3rd infusions," and the summary also says that bitterness and astringency in the sensory test were felt at similar intensity in the 1st and 2nd infusions and weaker in the 3rd. Table 3 gives the tannin in the 1st infusion of sencha as 6.69 (0.5 min), 9.46 (1 min), 18.38 (2 min), 22.23 (3 min), and 25.47 (4 min) mg/80 mL. The text states that, in an analysis of variance pooling all tea types, tannin extraction increased with longer steeping, with no significant difference between 3 and 4 minutes but significant differences when times differed by 1 minute or more.
Limitations: The bitterness and astringency scores for each steeping time are not shown in the text, so this rests on the authors' statement that differences were small. No test of the effect of steeping time on sensory scores is given.
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ingredient-green-tea —has_perceived_bitterness_unchanged_by→ (the claim sentence above)claim: clm-sencha-steeping-time-sensory-small-yoneda-1994 / type: sensory / updated: 2026-10-06
green tea infusion shows the sensory response In commercial sencha steeped in 80°C water, bitterness and astringency were felt at similar levels in the 1st and 2nd infusions and became weaker in the 3rd (averages over all steeping times; bitterness for infusions 1–3: 0.53, 0.20, −0.87; astringency: 0.66, 0.54, −0.53). While gyokuro kept bitterness and astringency at a moderate level from the 1st to the 3rd infusion, all items in sencha weakened with repeated infusions.supported
Scope: 1 commercial Uji sencha sample (3 g, 80 mL of 80°C water, steeped for 0.5–4 min, 3 infusions from the same leaves). 15 faculty and staff members rated it individually on a 5-point scale from −2 to +2.
Note: The difference between the 1st and 2nd infusions was not tested for significance. The infusions were evaluated in the order 2nd, 1st, 3rd.
The Table 5 sencha averages over all steeping times are, for bitterness, 0.53 (1st infusion), 0.20 (2nd), and −0.87 (3rd), and for astringency 0.66, 0.54, and −0.53. The text says that gyokuro's bitterness and astringency changed little from the 1st to the 3rd infusion, whereas all items in sencha were felt to weaken as infusions were repeated; the summary says bitterness and astringency were felt at similar intensity in the 1st and 2nd infusions and weaker in the 3rd.
Limitations: No test is given for the difference between the 1st and 2nd infusions or between the 2nd and 3rd. A single commercial product.
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ingredient-green-tea —has_sensory_response→ (the claim sentence above)claim: clm-sencha-repeated-infusion-weaker-bitterness-astringency-yoneda-1994 / type: sensory / updated: 2026-10-06
green tea infusion shows the sensory response Kabusecha was steeped in 90°C, 50°C, and 20°C water for 5 minutes and in 5°C water for 30 minutes, and 22 panelists rated the astringency of each infusion on a 5-point scale relative to the 50°C infusion (strong +2 to weak −2). The 90°C infusion was stronger than the reference (about +1.6, read from the figure), while the 20°C (about −1.1) and 5°C, 30-minute (about −1.0) infusions were weaker. The authors state that the sample infused at 90°C was extremely astringent. Astringency ratings correlated significantly and positively with the logarithm of total catechin concentration (r²=0.79, p<0.05) and the logarithm of galloylated catechin concentration (r²=0.94, p<0.01); galloylated catechins in the 90°C infusion were about 2.2 times those in the 50°C infusion (0.73 mM vs 0.33 mM).supported
Scope: Kabusecha from the 2011 harvest (Yabukita). Infusions made by placing 25 g of tea and 1 L of water in a glass pot and letting it stand were rated for astringency relative to the 50°C infusion by 22 people working in tea research, extension, or business.
Note: The ratings are approximate values read from a figure, and what was rated was astringency and umami, not bitterness. The analysis used only 5 samples (4 infusion conditions of kabusecha B and the 50°C infusion of kabusecha C). The tea type is kabusecha, not sencha. No tests of differences between individual conditions are given.
The sensory value (astringency) correlated significantly and positively with the logarithm of total catechin concentration (y=1.8ln(x)+0.76, r²=0.79*) and with the logarithm of galloylated catechin concentration (y=1.5ln(x)−2.0, r²=0.94**), the latter being higher. In Fig. 5, with the 50°C infusion of kabusecha B as the reference (0), the 90°C infusion is at about +1.6 and the 20°C and 5°C (30 min) infusions at about −1 to −1.1. The text states that the sample infused at 90°C was shown to be extremely astringent in sensory evaluation as well. Table 4 gives galloylated catechins of kabusecha B as 0.73 (90°C), 0.33 (50°C), 0.11 (20°C), and 0.18 (5°C, 30 min) mM.
Limitations: The analysis covers only 5 samples. The values are approximate readings from a figure. Astringency and umami were rated, not bitterness. Because the reference is the 50°C infusion, they are not absolute intensities.
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ingredient-green-tea —has_sensory_response→ (the claim sentence above)claim: clm-kabusecha-water-temperature-astringency-sensory-kubo-2014 / type: sensory / updated: 2026-10-06
green tea infusion shows the sensory response When sencha (Yabukita, 2010 harvest) was steeped in 90°C water for 0.5–10 minutes, or in 30–100°C water for 5 minutes, total catechin concentration rose from 0.35 mM at 0.5 min to 1.02 mM at 10 min, and from 0.32 mM at 30°C to 1.05 mM at 100°C; galloylated catechins also rose from 0.25 to 0.79 mM and from 0.19 to 0.82 mM. The taste sensor's astringency estimate correlated highly with the logarithm of total catechin and galloylated catechin concentrations under all conditions (r²=0.98–1.00). The taste sensor's astringency estimate was higher with hotter water and longer steeping.preliminary
Scope: 1 sencha sample. Infusions were made by pouring 200 mL of water onto 2 g of tea, letting it stand, and cooling in an ice bath. Estimates were obtained with a taste sensor (AE1 sensor for astringency, referenced to 0.65 mM epigallocatechin gallate).
Note: These are taste-sensor estimates of astringency and are not equated with human sensory evaluation (in Experiment 2 of the same report, a high positive correlation was shown between the astringency estimate and human astringency ratings for infusions such as kabusecha). It is an estimate of astringency, not bitterness.
The astringency estimate correlated highly with the logarithm of total catechin and galloylated catechin concentrations (Fig. 1: total catechin y=5.7ln(x), r²=0.98***; Fig. 2: y=6.0ln(x)−0.3, r²=1.00***; galloylated y=5.0ln(x)−0.88, r²=1.00***). Table 2 gives catechin concentrations at 90°C from 0.5 to 10 minutes, and Table 3 at 5 minutes from 30°C to 100°C (total catechin 0.35→1.02 mM, 0.32→1.05 mM).
Limitations: These are taste-sensor estimates, not human sensory evaluation. They estimate astringency and are not an index of bitterness.
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ingredient-green-tea —has_sensory_response→ (the claim sentence above)claim: clm-sencha-temperature-time-catechin-astringency-taste-sensor-kubo-2014 / type: sensory / updated: 2026-10-06
green tea infusion shows the sensory response Under the condition of adding 200 mL of water to 3 g of deep-steamed sencha, the same leaves were infused in turn with 5°C water (10 min), 40°C water (1 min), and 100°C water (1 min). The taste sensor's astringency intensity rose greatly from 5°C to 40°C, and umami intensity decreased. Catechin content of the infusions was 19.0 (5°C), 26.3 (40°C), and 60.7 (100°C) mg/100 mL, and the authors state that astringency intensity tended to increase with infusion temperature.preliminary
Scope: Deep-steamed sencha from Kawane, Shizuoka (Yabukita first flush, 2011 harvest). Taste sensor (SA402B) measurements and HPLC catechin quantification.
Note: These are taste-sensor measurements and are not equated with human sensory evaluation. The result comes from infusing the same leaves in turn at 5°C, 40°C, and 100°C, using leaves already well swollen by the cold infusion, and differs from results with separate fresh leaves at each temperature (with separate leaves, astringency intensity rose slightly from 5°C to 40°C). It is astringency intensity, not bitterness.
The text states that when the same leaves were infused in turn at 5°C, 40°C, and 100°C, astringency intensity rose greatly at 40°C compared with 5°C and umami intensity decreased. Catechin content for the same leaves was 19.0 (water infusion), 26.3 (lukewarm infusion), and 60.7 (hot infusion) mg/100 mL (38, 52, and 120 mg per 200 mL). Summary item 4) states that astringency intensity tended to increase with temperature, while umami intensity dropped sharply at lukewarm (40°C) and did not change afterward. In the comparison using separate leaves, astringency intensity rose slightly at 5°C and 40°C.
Limitations: These are taste-sensor measurements, not human sensory evaluation. The sequential infusion of the same leaves starts from leaves swollen by cold water. The astringency intensity values are not in the text and must be read from a figure.
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ingredient-green-tea —has_sensory_response→ (the claim sentence above)claim: clm-sencha-water-temperature-astringency-taste-sensor-uchiyama-2013 / type: sensory / updated: 2026-10-06
green tea infusion shows the sensory response When 1–10 g of deep-steamed sencha was steeped for 1 minute in 200 mL of hot water, the taste sensor's astringency intensity rose almost linearly up to 2 g of leaves and increased only gradually beyond that. Catechin content rose to 19.7, 60.0, 91.4, and 169.0 mg/100 mL for 1 g, 2 g, 3 g, and 5 g of leaves, but did not correspond to the change in astringency intensity. In a paired comparison (2-point) test with a trained panel of 5, it was difficult to rate astringency as dependent on leaf concentration at 3 g of leaves or more.preliminary
Scope: Deep-steamed sencha from Kawane, Shizuoka (Yabukita first flush, 2011 harvest). Taste sensor (SA402B) measurements, HPLC catechin quantification, and a paired comparison (2-point) test by a trained panel of 5 (reference: infusion of 1 g of leaves).
Note: The authors point out that the taste sensor may saturate as leaf amount increases. The sensory evaluation was small, with 5 panelists; the number of people and the result are as stated verbatim in the source. It is astringency intensity, not bitterness.
The text states that "astringency intensity increased up to 2 g of leaves but was shown to increase only gradually thereafter." Catechin content increased to 19.7, 60.0, 91.4, and 169.0 mg/100 mL for 1 g, 2 g, 3 g, and 5 g of leaves, but did not correspond to the taste sensor's astringency intensity. In sensory evaluation (trained panel of 5, paired comparison (2-point) test referenced to the infusion of 1 g of leaves), it was difficult to rate umami and astringency as dependent on leaf concentration at 3 g of leaves or more.
Limitations: The study centers on taste-sensor measurements, and human sensory evaluation is only a description of a paired comparison (2-point) test with 5 panelists. No numerical rating values are given. It is astringency intensity, not bitterness.
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ingredient-green-tea —has_sensory_response→ (the claim sentence above)claim: clm-sencha-leaf-amount-astringency-taste-sensor-uchiyama-2013 / type: sensory / updated: 2026-10-06
green tea infusion — combined bitter-astringent taste is affected by: 7 commercial cold-brew senchas were infused at 100 mL of distilled water (7–8°C) per 1 g of tea for 5 minutes, 30 minutes, 2 hours, and 10 hours, and the preference for color, aroma, and taste was evaluated by the ranking method; except for a few samples, the 30-minute to 2-hour infusions were preferred. The authors consider that the 5-minute infusion was rated low because few components had been extracted, and the 10-hour infusion because tannin (an astringent component) increased and the bitter-astringent taste became stronger. Tannin was slow to extract: the share extracted relative to the amount in the tea was about 15–30% at 30 minutes, 19–40% at 2 hours, and 30–60% at 10 hours, whereas free amino acids were already about 40–70% extracted at 30 minutes.preliminary
Scope: 7 commercial cold-brew senchas. 10 staff members of the Vegetable and Tea Research Station of the Ministry of Agriculture, Forestry and Fisheries (Makurazaki) and 10 junior college women students evaluated color, aroma, and taste by the ranking method (Kramer's rank-sum test).
Note: What was evaluated was preference rank; the strength of bitterness and astringency was not measured directly. The link between the lower rating at 10 hours and bitter-astringent taste is the authors' interpretation based on increased tannin extraction. The students tended to prefer shorter steeping times than the general panel, which the authors infer is because they prefer a lighter bitter-astringent taste. "Bitter-astringent taste" (kujūmi) is an expression that combines bitterness and astringency into one.
The abstract states that "the 30-minute and 2-hour infusions were generally rated highest in taste, aroma, and color; the 5-minute infusion was rated low because few components were extracted and the 10-hour infusion because of the high concentration of tannin, an astringent component. Tannin extraction was very slow, amino acids were extracted quickly, and caffeine was intermediate." The discussion states that "at 10 hours the amount of tannin increased, so the bitter-astringent taste became stronger and preference decreased," and that the students tended to prefer a light, mild taste with little bitter-astringent taste. The summary says that the steeping times with high preference for both the general panel and the students were, with a few exceptions, 30 minutes to 2 hours.
Limitations: This was not a test that directly rated the strength of bitterness or astringency, but a preference ranking. The mention of bitter-astringent taste is the authors' discussion, and the cause of the lower rating at 10 hours was not separated by sensory testing. The panel was 20 people.
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ingredient-green-tea —has_bitter_astringency_affected_by→ (the claim sentence above)claim: clm-sencha-coldwater-soaking-time-bitter-astringent-fukushiyama-1999 / type: sensory / updated: 2026-10-06
green tea infusion — combined bitter-astringent taste is affected by: Chinese green tea (Longjing tea) was steeped for 4 minutes in 70, 80, 90, and 100°C water and rated on a 0–10 scale by a trained panel of 9. For standard-grade Longjing tea, the authors report that from 70°C to 100°C bitterness rose significantly from 3.13 to 5.17 and astringency from 2.07 to 4.13 (p<0.05; whether differences between adjacent temperatures were significant appears only in a figure and was not checked). From 70°C to 100°C, bitterness and astringency scores increased by 33.25% and 36.72% in the high-grade tea and by 64.92% and 99.98% in the standard tea. The authors conclude that low water temperatures of 70–80°C weakened bitterness and astringency and strengthened umami.supported
Scope: 2 grades of Longjing tea, high grade and standard grade. Steeped for 4 minutes in 70, 80, 90, and 100°C water. Infusions held at 45°C were evaluated by quantitative descriptive analysis (0–10 scale) by a trained panel of 9 (trained for 3 months or more).
Note: Bitterness and astringency were rated as separate attributes. The amounts of tea leaves and water are not stated in the text. The figures are the values the text gives for the change from 70°C to 100°C in the standard grade (SL); for the high grade, only the rates of increase are given. This is Chinese Longjing tea, not Japanese sencha.
The Abstract states "lower brewing temperatures (70–80 °C, with 70 °C optimal) enhanced umami taste while diminishing bitterness and astringency". The Results state "With the increase of BT, the umami-mellow taste of PL significantly weakened, from 8.10 to 5.60 (p < 0.05), while bitterness (3.13 → 5.17, p < 0.05) and astringency (2.07 → 4.13, p < 0.05) of SL significantly enhanced". Section 3.2.1 states "The bitterness and astringency score of PL increased by 33.25 % and 36.72 % from 70 °C to 100 °C, while the score in SL rose by 64.92 % and 99.98 %".
Limitations: The amounts of tea leaves and water are not stated in the text. The score changes are given for the standard grade from 70°C to 100°C, and scores at each temperature are available only in a figure. Longjing tea differs from Japanese sencha.
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ingredient-green-tea —has_bitter_astringency_affected_by→ (the claim sentence above)claim: clm-longjing-green-tea-brewing-temperature-bitterness-astringency-deng-2025 / type: sensory / updated: 2026-10-21
green tea infusion — combined bitter-astringent taste is affected by: When 5 g of Chinese green tea (Shucheng Xiaolanhua) was steeped in 250 mL of 85°C water for 4 minutes, the infusion made by adding the water first and the leaves afterward (top-down method) showed significantly stronger bitterness than the one made by putting the leaves in first and pouring water onto them (bottom-up method). The top-down infusion also had a higher total polyphenol content (101.50 mg/g vs 90.87 mg/g).preliminary
Scope: 1 sample of Shucheng Xiaolanhua (a green tea from Anhui, China). 10 people (aged 22–30) rated bitterness, astringency, and other attributes on a 0–5 scale. The study's main subject is the analysis of aroma compounds, and its sensory evaluation was only a comparison of the 2 methods at 85°C.
Note: The bitterness scores and test results are in a figure; the text only says "significantly stronger bitterness" and gives no numbers. The result of the astringency comparison is not given in the text. The difference in polyphenol content, proposed as the reason for the bitterness difference, is an analytical value and has not been directly tied to sensory results.
The text notes that the tea infusion brewed by the TB method showed a significantly stronger bitter taste, which may be attributable to its higher polyphenol content. Elsewhere it says that TB-brewed tea had significantly higher OAVs for aroma compounds, with a strong fresh and floral fragrance but also relatively pronounced bitterness, whereas BB-brewed tea had milder bitterness and a stronger chestnut-like aroma. Total polyphenols were 101.50 mg/g for TB and 90.87 mg/g for BB, significantly higher in TB.
Limitations: The bitterness scores and test numbers are only in a figure, not in the text. The astringency comparison result is not given in the text. The explanation that top-down brewing is more bitter because of its polyphenol content is the authors' inference.
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ingredient-green-tea —has_bitter_astringency_affected_by→ (the claim sentence above)claim: clm-green-tea-top-vs-bottom-brewing-bitterness-zheng-2026 / type: sensory / updated: 2026-10-06
green tea infusion — combined bitter-astringent taste is affected by: When green tea (Yuhua green tea) was cold-brewed at a tea:water ratio of 1:50 at 4°C for 6 hours, the taste was described differently depending on the type of water used. The infusion made with pure water was described by 5 trained panelists as "brightly bitter," and its taste-sensor bitterness value was also the highest. The infusion made with reverse-osmosis drinking water (moderate calcium and magnesium, neutral) was described as having a "fresh and brisk sweet aftertaste," and its taste-sensor sweetness value was the highest. Infusions made with pure and distilled water contained more EGCG and caffeine (EGCG: 4.50% pure water, 4.29% distilled water, 4.10% RO-treated water, 3.32% mineral water), and the authors discuss that bitterness and astringency were stronger.preliminary
Scope: 1 special-grade Yuhua green tea. Steeped for 6 hours in a 4°C refrigerator and served at 4°C. Descriptive evaluation by 5 trained panelists (aged 24–42) and taste-sensor (SA402B) measurements.
Note: The human evaluation is vocabulary agreed on by 5 people, and no scores or test values are given. The statements that bitterness was "highest" or "lowest" are taste-sensor measurements and are not equated with human sensory evaluation. This is the effect of water quality in cold brewing, not a comparison of different water temperatures or steeping times. Which group had the lowest bitterness is described inconsistently in the paper (there are sentences that assign it both to the RO-treated water group and to the mineral water group), so this claim does not state it.
Results 3.4 states that in sensory evaluation (Table 1) PWT was described as brightly bitter, and the pie chart (Fig. 3) showed its bitterness as the highest along with the lowest sweetness and umami. DDWT, in contrast, was described as fresh and brisk with a sweet aftertaste, and ET showed the highest sweetness and the lowest bitterness among all samples (p < 0.05). The EGCG in Table 2 is 4.50% for pure water, 4.29% for distilled water, 4.10% for RO-treated water, and 3.32% for mineral water.
Limitations: The human evaluation is a description in words with no scores, and the bitterness numbers are electronic tongue measurements. This is an effect of water quality, not of water temperature or time. There is a contradictory statement about the bitterness of the mineral water.
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ingredient-green-tea —has_bitter_astringency_affected_by→ (the claim sentence above)claim: clm-green-tea-cold-brew-water-type-bitterness-ye-2026 / type: sensory / updated: 2026-10-06
green tea infusion shows the sensory response Cold-infused green tea from Taiwan (unfermented Bi Luo Chun), made with 50 times its volume of water at 4–5°C for 6 hours, was evaluated for 30 seconds by 63 consumers using temporal check-all-that-apply (TCATA). Bitterness was selected significantly more often than the average of the other 6 teas (5 oolongs and a black tea) from 5 seconds after the first sip and continued to the end of the evaluation. Among the 7 teas, this tea was characterized as strong in bitterness, astringency, and pungency and weak in sweet aftertaste and floral aroma.preliminary
Scope: Cold infusion of 1 Bi Luo Chun (from New Taipei City, Taiwan) at 4–5°C for 6 hours. 63 university students in Taiwan (25 men, 38 women) rated it by TCATA (9 terms: sweet, sour, bitter, astringent, roasted aroma, raw tea leaf aroma, floral aroma, sweet aftertaste, pungency). The reference was the average selection frequency of the other 6 teas. The infusion was taken out of the refrigerator and served after returning to room temperature.
Note: The statement is that even with cold infusion the green tea was placed among the strongly bitter teas; it includes no comparison with hot infusion. The cold-brew condition (4–5°C, 6 hours) was the same for all samples and is longer than the recommended time for green tea (4 hours). Bitterness and astringency were selected as separate terms. These are selection frequencies, not numerical intensity ratings. This is a relative comparison of 1 green tea and 6 more highly fermented teas, not a comparison varying infusion conditions.
The text states "as soon as the cold BLC infusion was sipped, people could perceive its bitterness which then quickly turned significantly stronger than the reference intensity after 5 s, and this strong bitterness was sustained until the end of the evaluation", and "unfermented BLC was significantly characterized for its strong bitterness, astringency, pungency, as well as weak late sweetness and floral flavor". The infusion is described as "all of the cold tea infusions for this research were soaked statically in the sealed jars at 4–5 °C for 6 h", with the water at 50 times the amount of tea.
Limitations: This is not a comparison of cold and hot infusion but a relative comparison of 7 teas. It gives selection frequencies, not numerical intensities. Only 1 green tea sample was used, and it is not Japanese sencha.
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ingredient-green-tea —has_sensory_response→ (the claim sentence above)claim: clm-green-tea-cold-infusion-strong-bitterness-tcata-liu-2021 / type: sensory / updated: 2026-10-06