Acknowledgments
Caffeine Estimator Sources
Last updated: 2 September 2026
Scientific evidence in the released model lineage
Dry-leaf inventory, tea identity, processing, and biological variation
| Publication | How Teample used it | Recorded reuse status |
|---|---|---|
| Ning et al. (2017), Discrimination of six tea categories coming from different origins depending on polyphenols, caffeine, and theanine combined with different discriminant analysis — DOI | Broad six-family commercial dry-inventory evidence | License not frozen in the evidence snapshot |
| Astill, Birch, Dacombe, Humphrey & Martin (2001), Factors Affecting the Caffeine and Polyphenol Contents of Black and Green Tea Infusions — DOI | Green/black inventory context and destructive time-curve evidence | Publisher copyright; no open license identified |
| Li et al. (2023), Quantitative Analysis of Bioactive Compounds in Commercial Teas: Profiling Catechin Alkaloids, Phenolic Acids, and Flavonols Using Targeted Statistical Approaches — DOI | Commercial-product family inventory evidence | CC BY 4.0 |
| Sun et al. (2019), Comprehensive Analysis Revealed the Close Relationship between N/P/K Status and Secondary Metabolites in Tea Leaves — DOI | Regional oolong dry-inventory panel | CC BY 4.0 |
| Goto et al. (1992), Chemical Composition of Prized Japanese Green Tea in National Tea Competition. 1 — DOI | Japanese green-tea inventory context | Publisher copyright; no open license identified |
| Goto et al. (1994), Chemical Composition of Japanese Green Teas on Market — DOI | Japanese market inventory context | Publisher copyright; no open license identified |
| Goto et al. (1996), Contents of Individual Tea Catechins and Caffeine in Japanese Green Tea — DOI | Japanese market class-inventory panel | Publisher copyright; no open license identified |
| Catechin Composition, Phenolic Content, and Antioxidant Properties of Commercially-Available Bagged, Gunpowder, and Matcha Green Teas (2023) — DOI | Ten-product Matcha dry-inventory evidence | License not frozen in the evidence snapshot |
| Metabolite profiling and transcriptome analyses provide insight into the chemical transformation of six types of tea (2021) — DOI | Same-harvest, same-cultivar comparison of six processing styles | CC BY 4.0 |
| Collings et al. (2019), Spatial changes in leaf biochemical profile of two tea cultivars following cold storage under two different vapour pressure deficit (VPD) conditions — DOI | Bud/small-leaf and stem/twig inventory priors | CC BY according to the current publication record |
| Qiushuang Zhang et al. (2020), Screening Tea Cultivars for Novel Climates: Plant Growth and Leaf Quality of Camellia sinensis Cultivars Grown in Mississippi, United States — DOI | Weak, region-conditioned seasonal inventory priors | CC BY 4.0 |
| Qianwen Zhang et al. (2022), Color Shade Nets Affect Plant Growth and Seasonal Leaf Quality of Camellia sinensis Grown in Mississippi, the United States — DOI | Explicit-shade inventory prior | CC BY 4.0 |
| Tfouni et al. (2018), Caffeine in teas: levels, transference to infusion and estimated intake — DOI | Linked commercial-product dry inventory and infusion transfer | CC BY 4.0 |
| Pedan et al. (2018), Bioactive Compound Fingerprint Analysis of Aged Raw Pu'er Tea and Young Ripened Pu'er Tea — DOI | Linked raw/ripened Pu'er inventory and temperature evidence | CC BY 4.0 |
| Hinton et al. (2022), GABA-enriched Oolong Tea: Reducing Stress in a Student Cohort May Involve More than Just GABA — DOI | Product-level oolong brew replicates | CC BY 3.0 |
| Jankech et al. (2019), Determination of methylxanthines in tea samples by HPLC method — DOI | Commercial Gyokuro holdout and later development context | CC BY-NC-ND 4.0 |
| Nakamura & Uehara (2020), Tastes of Green Tea ~Feel and Experience Chemistry~ — repository record | Aggregate commercial Gyokuro context outside the initial scored domain | CC BY-NC-ND 3.0 |
| Unno et al. (2025), Stress-Relieving Effects of Japanese Green Tea: Evaluation Using the Molar Ratio of Caffeine and Epigallocatechin Gallate to Theanine and Arginine as an Indicator — DOI | Same-product dry inventory, protocol anchor, and limited volume-shape context | CC BY 4.0 |
| Ayakdaş & Ağagündüz (2025), Determination of L-Theanine and Caffeine Contents in Tea Infusions with Different Fermentation Degrees and Brewing Conditions Using the Chromatographic Method — DOI | Broad family/form brew panel used in the inherited hierarchy | CC BY 4.0 |
| NARO, New green tea cultivar “Seimei” for sencha, kabusecha, matcha and powdered tea — publication PDF | Comparative cultivar-development evidence | License not recorded in the evidence manifest |
| Zhang et al. (2026), Biochemical Profiles, Mineral Accumulation, and Water-Soluble Fluoride Traits of 65 Tea (Camellia sinensis) Cultivars — DOI | Relative within-study cultivar inventory evidence | CC BY 4.0 |
| Kawahara et al. (2024), Chromosome-Scale Genome Assembly and Characterization of Top-Quality Japanese Green Tea Cultivar “Seimei” — DOI | Directional validation of Japanese cultivar effects; no anonymous point was assigned to a named cultivar | CC BY 4.0 |
Extraction kinetics, finite water, form, and successive infusions
| Publication | How Teample used it | Recorded reuse status |
|---|---|---|
| Price & Spiro (1985), Kinetics and equilibria of tea infusion: Rates of extraction of theaflavin, caffeine and theobromine from several whole teas and sieved fractions — DOI | Particle-size rate prior and finite-water physics foundation | Publisher copyright; no open license identified |
| Spiro, Jaganyi & Broom (1992), Kinetics and equilibria of tea infusion: Part 9. The rates and temperature coefficients of caffeine extraction from green Chun Mee and black Assam Bukial teas — DOI | Temperature dependence, rates, and equilibrium anchors | Publisher copyright; no open license identified |
| Jaganyi & Mdletshe (2000), Kinetics of tea infusion, Part 2. The effect of teabag material on the rate and temperature dependence of caffeine extraction from black Assam tea — DOI | Loose-versus-bag transport evidence | Publisher copyright; no open license identified |
| Jaganyi & Ndlovu (2001), Kinetics of tea infusion. Part 3: the effect of tea bag size and shape on the rate of caffeine extraction from Ceylon orange pekoe tea — DOI | Bag-area/confinement rate lookups | Publisher copyright; no open license identified |
| Hicks et al. (1996), Tea preparation and its influence on methylxanthine concentration — DOI | Three-brew depletion and bag/loose route evidence | Publisher copyright; no open license identified |
| Ma et al. (2020), Effect of brewing conditions using a single-serve coffee maker on black tea (Lapsang Souchong) quality — DOI | Seven-brew sequence plus volume and particle experiments | CC BY 4.0 |
| Yoneda & Kato (1994), Relationship between Taste and Concentrations of Caffeine and Tannin in Tea Infusion — DOI | Development sequences and a later sealed multitea, three-infusion challenge | Publisher copyright; no open license identified |
| Yamazawa et al. (2022), Effects of the Type of Sencha Green Tea Leaves and the Number of Infusions on Infusion Components and Taste Preferences — DOI | Commercial Sencha repeated-sequence calibration | Free-access publisher PDF; no Creative Commons license identified |
| Taniguchi et al. (2012), Elution Characteristics of Catechins and Caffeine in Kamairi-cha — DOI | Controlled process-fraction calibration | Publisher copyright; no open license identified |
| Zimmermann & Drees (2025), Let's have another cup of green tea! — DOI | Repeated-pair development evidence and later product-level external validation across 17 green teas | CC BY 4.0 |
| Yang, Hwang & Lin (2007), Effects of different steeping methods and storage on caffeine, catechins and gallic acid in bag tea infusions — DOI | Multi-temperature, eight-infusion challenge; later adaptive multi-steep evidence | Publisher copyright; no open license identified |
| Sharma, Gulati & Ravindranath (2005), Extractability of tea catechins as a function of manufacture procedure and temperature of infusion — DOI | Adaptive morphology/hydration evidence after the candidate route existed | Publisher copyright; no open license identified |
| Xiaoying Zhang, Yusuf, Xu & Isah (2026), Three Successive Infusions: Scientific Insights Into a Traditional Green Tea Drinking Custom — DOI | Sealed sequence-shape challenge, then adaptive wet-rest/fine-particle evidence | License not frozen in the evidence manifest |
| Wei et al. (2024), Chemical profiles, dissolution patterns, and in vitro bioactivities of selenium-enriched green teas: impact of brewing conditions — DOI | Sealed four-brew challenge, then adaptive duration-domain evidence | CC BY 4.0 |
| Sifeng Zhang et al. (2020), Prediction of suitable brewing cuppages of Dahongpao tea based on chemical composition, liquor colour and sensory quality in different brewing — DOI | Sealed 14-brew whole-leaf oolong challenge, then adaptive sequence-shape evidence | License not frozen in the evidence manifest |
| Cao et al. (2022), Optimization of brewing conditions for Tieguanyin oolong tea by quadratic orthogonal regression design — DOI | Sealed three-brew whole-leaf oolong challenge, then adaptive sequence-shape evidence | License not frozen in the evidence manifest |
| Sakamoto et al. (2002), Influence of Brewing Temperature and Number of Infusions on the Taste of Sencha — DOI | Sealed Sencha temperature-by-infusion validation | Publisher copyright; no open license identified |
| Lembono et al. (2026), The Effects of Brewing Condition on Tea's Caffeine Content and Sensory Quality — DOI | Post-freeze external temperature/time validation | License not recorded in the evidence manifest |
| Cho et al. (2026), Effects of brewing conditions on the sensory and chemical properties of Turkish black tea and their interrelationships — DOI | Post-freeze high-ratio, long-infusion temperature and plateau validation | CC BY-NC-ND 4.0 |
| Joshi & Yadav (2016), Swelling kinetics of tea in hot water — DOI | Hydration prior only; not treated as a caffeine observation | Publisher copyright; no open license identified |
Historical selection and benchmark evidence
These studies were used in predecessor selection or benchmarking. They remain part of the audit trail, but their measurements are not presented as untouched confirmation of the current Alpha10.20 release.
| Publication | How Teample used it | Recorded reuse status |
|---|---|---|
| Saklar, Ertaş, Özdemir & Karadeniz (2015), Effects of different brewing conditions on catechin content and sensory acceptance in Turkish green tea infusions — DOI | Digitized time-by-temperature outcomes in the historical comparison set | Publisher copyright; no open license identified |
| Suteerapataranon, Butsoongnern, Punturat, Jorpalit & Thanomsilp (2009), Caffeine in Chiang Rai tea infusions: Effects of tea variety, type, leaf form, and infusion conditions — DOI | Green/oolong form, temperature, and contact-time outcomes in the historical comparison set | Publisher copyright; no open license identified |
Scientific design context not used as current numerical calibration
The following publications shaped requirements, plausibility checks, or domain boundaries. They did not contribute a current Alpha10.20 coefficient unless the same publication is separately listed above with a development role.
- Zhao et al. (2019), Phenolic Profiles and Antioxidant Activities of 30 Tea Infusions from Green, Black, Oolong, White, Yellow and Dark Teas — DOI. Used for cumulative extraction context across successive boiling-water extractions. CC BY 4.0.
- Spiro & Price (1987), Kinetics and equilibria of tea infusion: Part 7—The effects of salts and of pH on the rate of extraction of caffeine from Kapchorua Pekoe Fannings — DOI. Used for water-chemistry and boundary context. Publisher copyright; no open license identified.
- Wang et al. (2022), Multi-Metabolomics Coupled with Quantitative Descriptive Analysis Revealed Key Alterations in Phytochemical Composition and Sensory Qualities of Decaffeinated Green and Black Tea from the Same Fresh Leaves — DOI. Used as decaffeination/process context, not as a universal residual-caffeine prior. CC BY 4.0.
- Liang, Lu & Zhang (2007), Decaffeination of fresh green tea leaf (Camellia sinensis) by hot water treatment — DOI. Used to bound an explicitly labelled engineering prior for tea declared decaffeinated without a product assay. Publisher copyright; no open license identified.
- Nakagawa (1969), Correlation of the Constituents with the Organoleptic Evaluation of Green Tea Liquors — DOI. Preserved as never-fit external evidence because its assay is less specific than chromatographic caffeine assays. CC BY-NC-SA 4.0 as marked by J-STAGE.
Academic models and measurements used only for comparison
These publications defined the scientific comparison set. Their equations, data, and code are not incorporated into the Teample runtime. Publications already listed above are not repeated here.
- Price & Spiro (1985), finite-water equilibrium companion — DOI.
- Stapley (2002), Fickian finite-volume slab/sphere analysis — DOI.
- Ziaedini, Jafari & Zakeri (2010), two-rate diffusion model — DOI.
- Fernando & Soysa (2015), second-order CTC black-tea extraction model — DOI.
- Lin, Xia & Liu (2017), white-tea Peleg extraction curves — DOI.
- Liu et al. (2018), green-tea response-surface model — DOI.
- Yu et al. (2021), black-tea response-surface model — DOI.
- Paramita et al. (2022), Bancha industrial-extract optimization — DOI.
- Duan et al. (2024), tea-residue response-surface and neural-network model — DOI.
- Lian & Astill (2002), mechanistic tea-bag solubilization model — DOI.
- Dhekne & Patwardhan (2020), porous tea-bag transport model — DOI.
Public calculators, apps, and product pages used only for comparison
Observed on 18 August 2026. These services supplied comparison context only; Teample does not incorporate their code or undisclosed formulas, and their listing here does not imply endorsement in either direction.
- Eco-Cha Advanced Tea Caffeine Calculator, its methodology article, and the linked Taiwan TRES report.
- Green Tea Nutrify.
- Yalla Herbal Tea Calculator.
- Kojo Roastery Caffeine Calculator.
- TeaFYI Caffeine Calculator and developer documentation.
- Miss Vickie general tea calculator and white-tea calculator.
- White Tea Central Brew Lab and caffeine methodology.
- GreenTea.st.
- Steep: Tea Timer & Brew Guide.
- TeaForCalm brewing data, Teas.co.uk brewing calculator, and MegaCalc tea brewing calculator were reviewed as brewing-guidance products; they were not counted as protocol-conditioned caffeine estimators.
Candidate evidence examined but excluded from the released estimator
A proposal snapshot also recorded the following papers. They are named here for research completeness, but the proposal snapshot is not in Alpha10.20's pinned execution lineage and these papers must not be described as evidence supporting the released estimates:
- Kalisz et al. (2024), Elimination of Toxic Solvents from Analytical Methods in Food Analysis: Caffeine Determination in Tea as an Example — DOI, CC BY 4.0.
- Sarmah et al. (2026), Biochemical Quality Profile of Black Tea from Upper Assam and North Bank Region of Assam, India — DOI, CC BY 4.0.
- Cheng et al. (2023), Hot Water Extraction of Antioxidants from Tea Leaves—Optimization of Brewing Conditions for Preparing Antioxidant-Rich Tea Drinks — DOI, CC BY 4.0.
- Komes et al. (2010), Green tea preparation and its influence on the content of bioactive compounds — DOI. Teample sealed a morphology-route challenge before opening the study's numerical outcomes, but no Komes evidence snapshot is pinned into Alpha10.20. Publisher copyright; no open license identified.
Wei et al. (2024) first appeared in that proposal snapshot and was later admitted through a separately governed Alpha10 evidence snapshot; it is therefore listed in the released lineage above.
First-party Teample sources
These are Teample inputs and test assets, not independent laboratory evidence:
- Teample cultivar authority. The normalized cultivar registry and its generated authority snapshot resolve identities and aliases. Its underlying registries, institutional records, and exact-label sources are documented in the tea-biology source register. A cultivar name receives a numerical caffeine effect only when matched to admitted scientific evidence; registry membership by itself is not a caffeine coefficient.
- Teample Catalog and grams-per-brew registry snapshot. Supplies reviewed tea classes and mass defaults. It is a product-data authority, not a caffeine assay.
- Eighteen-month real-brew protocol fixture. Contains 225 historical protocols, including 22 multi-serving protocols. It was used for request/routing, compatibility, and regression testing. Historical Alpha9/9.2 estimates are not ground-truth caffeine labels and were not used as laboratory accuracy targets.
- Founder-provided Teashelf scenarios. Used as product-level smoke and plausibility checks. They are not analytical measurements.
No personal account identifier belongs on the public acknowledgments page.
Engineering assumptions without an external source
The release also contains explicit temporary engineering assumptions. They are recorded here so that absence of a citation is not hidden:
- ordinary dried-tea moisture, pending normalized moisture evidence;
- uncertainty attached to L1–L5 grams-per-brew mass resolution;
- residual caffeine for a product declared decaffeinated without an assay, bounded using process evidence but not presented as a commercial-population interval.
These assumptions must remain labelled as engineering assumptions until a governed release replaces them with normalized evidence.
Open-source computational tools
The Python reference and scientific build/test pipeline use:
The portable consumer runtime is Teample code expressed as JavaScript and WebAssembly. JavaScript, WebAssembly, and JSON Schema are implementation standards, not sources of scientific evidence.
Attribution and non-endorsement
Where a source is licensed under Creative Commons, Teample's use may include transcription, normalization, unit conversion, aggregation, digitization, or derived model features. Those changes are Teample's. No author, institution, journal, publisher, registry, calculator, or product listed here endorses Teample or its caffeine estimator. Any error in Teample's transcription, normalization, inference, or implementation remains Teample's responsibility.
The estimator's current release claim is bounded: it is the selected release in Teample's frozen repository comparison and passed the applicable Alpha10.20 contract gates. It has not been independently proven the world's most accurate caffeine estimator, and this acknowledgments page must not imply that claim.