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Sources & References

This is the trust page. It says who stands behind the site, what evidence each section rests on, and how to judge a claim — primary experience and records first, outside standards and data to verify, and clear labels on anything that is illustrative rather than current.

A technical reference is only as good as its sources. This page pulls them into one place so a claim anywhere on the site can be traced back to where it came from.

Who stands behind this​

The site is written by Craig Belser — founder, brewer, developer, and a celiac who has been brewing gluten-free since 2003. He helped found Bard's, developed the malted-sorghum beer behind it, and spent more than twenty years learning what gluten-free grain, malt, enzymes, process, and quality control actually demand in commercial production. Full background: About Craig and Bard's Story.

That means the technical guidance here is grounded in real production experience and records, not a clean theory exercise. It also means opinions are labeled as opinions, and the one non-negotiable is stated plainly: no wheat, barley, rye, or oats — ever.

The site uses AI to organize material and tighten writing. AI is not the source of the knowledge and does not overrule evidence, experience, or reality — see where AI fits.

How to judge a claim here​

  • Primary experience and records first. The brewing pages rest on real commercial production and quality records.
  • Outside standards and data to verify. Regulations, enzyme-maker documentation, and published research are cited where they carry the weight, not decoration.
  • Illustrative data is labeled. The market figures come from a 2019 study; every number is stamped illustrative, deliberately conservative, and not current — validate before making a live claim.
  • Measured vs. estimated. Where a figure is an in-house estimate rather than measured data, the site says so. When measured data and an estimate disagree, the measured data wins.

The Research Library — the primary record, published​

The strongest sources behind this site are no longer summarized — they're published. The Research Library holds the primary record in full: original datasets with downloadable CSVs and ready-to-paste citations, a survey of every evaluation methodology the field has used, and the standards we propose for the field to adopt or tear apart.

ShelfWhat's on itStart here
Data CatalogEvery published dataset, one row each, with downloads and citationsThe catalog
Cultivar dataThe USDA-ARS Madison screening (25 named cultivars) and the 2002–2004 screenings (74 more samples)USDA Madison Screening
Evaluation methodsEach methodology the field has used, reviewed on its own page, plus the side-by-side comparisonMethods Overview
Production dataIndependent laboratory analyses of production malt and finished beer — Hartwick, Midwest, and LCBO certificates in fullHartwick 2019
Proposed standardsSpecific, versioned, criticizable proposals — starting with sorghum malt evaluationGFB-SME draft
Research asksThe open questions, specified well enough to run — any scale welcomeResearch Asks

This library grows as archive records clear review. Each addition follows the same rules: programmatic transcription, full-precision downloads, honest provenance, and a citation block.

Each published dataset carries a DOI; the list below is generated from the dataset pages.

DatasetDOI
Hartwick 2019 Malt Analysis: The Founding Numbers, in Fulldoi:10.5281/zenodo.21879877
LCBO Finished-Beer Certificates: A Regulator's Numbersdoi:10.5281/zenodo.21880019
Midwest 2019 Grain Nutrition: The Same Malt, the Other Instrumentdoi:10.5281/zenodo.21880010
Production QA Log 2014–2017: Four Years of Batch Recordsdoi:10.5281/zenodo.21880028
Sorghum Malt Quality Data: The USDA Madison Screeningdoi:10.5281/zenodo.21879915
Sorghum Malt Screenings 2002–2004: Breeding Lines and Cultivar Searchdoi:10.5281/zenodo.21879934

Primary sources behind the knowledge base​

SectionWhat it rests onStart here
Brewing process & protocolsCommercial production records and protocol runs — real mashes, doses, temperatures, and outcomesThe Reliable Mash, Why the 190°F Baseline Exists, External Enzymes
Malting & grainThe production malting program's own quality standards, the USDA-ARS collaboration, and independent laboratory analyses of production maltCultivars for Malting, Why Native Malt Enzymes Are Not Enough
Quality, safety & trustIndependent laboratory analyses, official FGIS inspection results, and grain-acceptance records, organized into a farm-to-package trust chainQA Trust Chain, Grain Source & Acceptance
Market & business caseA 2019 target-audience research study built on MRI (Mediamark) syndicated consumer data, plus Bard's own consumer surveyWhat the 2019 Audience Research Found, Gluten Survey Results

Standards, regulations & literature​

How this list works: every claim that leans on an outside source is footnoted on the page that makes it — those per-page citations are the canonical record. This section is the organized survey of that record, generated from the site's own footnotes by npm run build:sources (last regenerated 2026-09-29; the build fails if this list falls behind the pages). It holds 120 outside sources across the knowledge base and the research library, filed by subject. If a page's footnote and this list ever disagree, the page wins and this list needs its refresh.

Regulation and official standards​

  • 7 CFR 810.1402(c), United States Standards for Sorghum: the four classes, Sorghum, Tannin sorghum, White sorghum and Mixed sorghum.
  • FDA, "Questions and Answers on the Gluten-Free Food Labeling Final Rule", and FDA, "Gluten and Food Labeling". Set the under-20-ppm standard for a gluten-free claim on FDA-regulated foods and the handling of fermented and hydrolyzed foods.
  • TTB Ruling 2008-3, Classification of Brewed Products as "Beer" Under the Internal Revenue Code of 1986 and as "Malt Beverages" Under the Federal Alcohol Administration Act (7 July 2008). Establishes that a fermented beverage qualifying as "beer" under the IRC but made without both malted barley and hops is not a malt beverage under the FAA Act, and that such products are subject to FDA labeling requirements under the Federal Food, Drug, and Cosmetic Act.
  • TTB Ruling 2020-2, Gluten Content Statements in the Labeling and Advertising of Wine, Distilled Spirits, and Malt Beverages. Products fermented from gluten-containing grains and processed to remove gluten must bear a qualifying statement to the effect that the product was fermented from grains containing gluten, was processed, treated or crafted to remove gluten, that the gluten content cannot be verified, and that the product may contain gluten.

Government agency publications and statistics​

Gluten detection and celiac safety​

  • Akobeng, A.K. & Thomas, A.G. (2008). Systematic review: tolerable amount of gluten for people with coeliac disease. Alimentary Pharmacology & Therapeutics. Used for the conclusion that daily intake under 10 mg is unlikely to cause significant histological change in most people. doi:10.1111/j.1365-2036.2008.03669.x
  • Al-Toma, A. et al. (2025). European Society for the Study of Coeliac Disease (ESsCD) 2025 Updated Guidelines… Part 2: Management, Follow-Up, and Complex Disease Courses. United European Gastroenterology Journal. doi:10.1002/ueg2.70195
  • Allred, L.K. et al. (2017). The Celiac Patient Antibody Response to Conventional and Gluten-Removed Beer. Journal of AOAC International. doi:10.5740/jaoacint.16-0184
  • Allred, L.K., Kupper, C. & Quinn, A. (2018). The Use of Visual Examination for Determining the Presence of Gluten-Containing Grains in Gluten Free Oats and Other Grains, Seeds, Beans, Pulses, and Legumes. Journal of AOAC International. doi:10.5740/jaoacint.170414
  • Catassi, C. et al. (2007). A prospective, double-blind, placebo-controlled trial to establish a safe gluten threshold for patients with celiac disease. The American Journal of Clinical Nutrition. Used for the 10 mg/day and 50 mg/day findings. doi:10.1093/ajcn/85.1.160
  • Coeliac Australia, Oats and the gluten-free diet (revised July 2025).
  • Comino, I. et al. (2011). Diversity in oat potential immunogenicity: basis for the selection of oat varieties with no toxicity in coeliac disease. Gut 60(7). PMC3112367
  • Dvořáček, V. et al. (2022). Specific Avenin Cross-Reactivity with G12 Antibody in a Wide Range of Current Oat Cultivars. Foods 11(4):567. doi:10.3390/foods11040567
  • Gluten Free Watchdog, Gluten Free Watchdog cannot recommend any brand of gluten-free oats.
  • Gluten Free Watchdog, Oats produced under a gluten-free purity protocol: listing of suppliers and manufacturers.
  • Gluten Free Watchdog, Summary of 2024 oat testing data.
  • Hardy, M.Y. et al. (2015). Ingestion of oats and barley in patients with celiac disease mobilizes cross-reactive T cells activated by avenin peptides and immuno-dominant hordein peptides. Journal of Autoimmunity. sciencedirect.com
  • Hardy, M.Y. et al. (2025). Purified-avenin oral challenge in celiac disease (Walter and Eliza Hall Institute). PubMed 39961645
  • Heredia-Olea, E., Cortés-Ceballos, E. & Serna-Saldívar, S.O. (2017). Malting Sorghum with Aspergillus oryzae Enhances Gluten-Free Wort Yield and Extract. Journal of the American Society of Brewing Chemists 75(2):116–121. Figures from the abstract; the full text is paywalled. doi:10.1094/ASBCJ-2017-2481-01
  • Huang, X. et al. (2024). A global view of oat immunogenicity for celiac disease, from genes to cellular response. Journal of Cereal Science 119. sciencedirect.com
  • National Celiac Association, Oats on the gluten-free diet.
  • Panda, R. & Garber, E.A.E. (2019). Detection and Quantitation of Gluten in Fermented-Hydrolyzed Foods by Antibody-Based Methods. Frontiers in Nutrition. doi:10.3389/fnut.2019.00097
  • Panda, R., Zoerb, H.F., Cho, C.Y., Jackson, L.S. & Garber, E.A.E. (2015). Detection and Quantification of Gluten during the Brewing and Fermentation of Beer Using Antibody-Based Technologies. Journal of Food Protection. doi:10.4315/0362-028X.JFP-14-546
  • Pinto-Sánchez, M.I. et al. (2017). Safety of Adding Oats to a Gluten-Free Diet for Patients With Celiac Disease: Systematic Review and Meta-analysis of Clinical and Observational Studies. Gastroenterology 153(2). gastrojournal.org
  • Real, A. et al. (2014). Identification and in vitro reactivity of celiac immunoactive peptides in an apparent gluten-free beer. PLOS ONE. doi:10.1371/journal.pone.0100917
  • Rubio-Flores, M., García-Arellano, A.R., Perez-Carrillo, E. & Serna-Saldivar, S.O. (2020). Use of Aspergillus oryzae during sorghum malting to enhance yield and quality of gluten-free lager beers. Bioresources and Bioprocessing 7:40. Open access, CC BY. doi:10.1186/s40643-020-00330-w
  • Thompson, T. et al., Gluten cross contact in oats: retrospective database analysis 2011 to 2023. Frontiers in Nutrition (2023). frontiersin.org/journals/nutrition/articles/10.3389/fnut.2023.1284636/full. 213 oat-containing packages tested 2011–2023; 24 (11%) at ≥5 ppm quantifiable gluten. Subscriber-selected products, not a random market survey.
  • Veith, K.N. (2009). Evaluation of four sorghum hybrids through the development of gluten-free beer. M.S. thesis, Food Science Institute / Grain Science and Industry, Kansas State University. Major professor J.A. Gwirtz. hdl.handle.net/2097/2281. Ranges quoted on this page verified against the thesis text 2026-08-23.

Malting safety, microbial control, and mycotoxins​

Foam and hop chemistry​

  • Ferreira, I.M. et al. (2005). Effects of the combination of hydrophobic polypeptides, iso-alpha acids, and malto-oligosaccharides on beer foam stability. Journal of Agricultural and Food Chemistry. doi:10.1021/jf047796w
  • Kunimune, T. & Shellhammer, T.H. (2008). Foam-Stabilizing Effects and Cling Formation Patterns of Iso-α-acids and Reduced Iso-α-acids in Lager Beer. Journal of Agricultural and Food Chemistry. doi:10.1021/jf8011079
  • Takoi, K. (2021). Influence of hop bitter acids and their derivatives on beer foam stability evaluated using customer-oriented Foam Collapse Time. BrewingScience. doi:10.23763/BrSc21-14takoi

Starch, wort, and fermentation chemistry​

  • Alves, S.L. et al. (2008). Molecular Analysis of Maltotriose Active Transport and Fermentation by Saccharomyces cerevisiae Reveals a Determinant Role for the AGT1 Permease. Applied and Environmental Microbiology 74(5):1494–1501. doi:10.1128/AEM.02570-07
  • Bajomo, M.F. & Young, T.W. (1993). The properties, composition and fermentabilities of worts made from 100% raw sorghum and commercial enzymes. Journal of the Institute of Brewing 99(2). doi:10.1002/j.2050-0416.1993.tb01158.x
  • Bajomo, M.F. & Young, T.W. (1994). Fermentation of worts made from 100% raw sorghum and enzymes. Journal of the Institute of Brewing 100(2). doi:10.1002/j.2050-0416.1994.tb00810.x
  • FAN limitation in sorghum brewing and its link to prolamin cross-linking: Free amino nitrogen improvement in sorghum malt brewing.
  • Hill, A. & Stewart, G.G. (2019). Free Amino Nitrogen in Brewing. Fermentation. doi:10.3390/fermentation5010022
  • HPD protein-body morphology and FAN: QTL Mapping of a High Protein Digestibility Trait in Sorghum bicolor; Influence of high protein digestibility sorghums on free amino nitrogen (FAN) production during malting and mashing.
  • Knudsen, K.E.B. (2014). Fiber and nonstarch polysaccharide content and variation in common crops used in broiler diets. Poultry Science 93(9):2380–2393. doi:10.3382/ps.2014-03902
  • Komlaga, G.A., Agbale, C.M., Najah, T. & Dowuona, S. (2021). Screening of Ghanaian sorghum varieties for lager style brewing. Journal of the Institute of Brewing. 26 varieties screened on germinative energy, green malt hydration, gelatinisation temperature, extract yield, limit attenuation, FAN and diastatic power; five suitable for lager malt without supplementary enzymes. doi:10.1002/jib.661
  • Novellie, L. (1982). Fermented beverages. In Proceedings of the International Symposium on Sorghum Grain Quality, 28–31 October 1981. ICRISAT, Patancheru, India.
  • Okolo, B.N. et al. (2020). Influence of malted barley and exogenous enzymes on the glucose/maltose balance of worts with sorghum or barley as an adjunct. Journal of the Institute of Brewing 126(1). doi:10.1002/jib.598
  • Peralta-Contreras et al. (2013). Fate of free amino nitrogen during liquefaction and yeast fermentation of maize and sorghums differing in endosperm texture. Food and Bioproducts Processing. doi:10.1016/j.fbp.2012.08.007
  • Sang, Y., Bean, S., Seib, P. A., Pedersen, J., & Shi, Y.-C. (2008). Structure and Functional Properties of Sorghum Starches Differing in Amylose Content. Journal of Agricultural and Food Chemistry. doi:10.1021/jf800577x
  • Šárka, E., Sinica, A., Smrčková, P., & Sluková, M. (2023). Non-Traditional Starches, Their Properties, and Applications. Foods 12(20), 3794. Quinoa across collected studies: onset 52.7–61.1 °C, peak 60.1–66.3 °C, conclusion 67.3–74.0 °C. doi:10.3390/foods12203794
  • Sindhu, R., Devi, A., & Khatkar, B. S. (2019). Physicochemical, thermal and structural properties of heat moisture treated common buckwheat starches. Journal of Food Science and Technology 56(5), 2480–2489. Native (untreated) control: onset 64.92 °C, peak 69.65 °C, conclusion 77.90 °C. doi:10.1007/s13197-019-03725-6
  • Stewart, G.G. (2016). Saccharomyces species in the Production of Beer. Beverages 2(4):34. doi:10.3390/beverages2040034
  • Taylor, J.R.N. & Boyd, H.K. (1986). Free α-amino nitrogen production in sorghum beer mashing. Journal of the Science of Food and Agriculture. doi:10.1002/jsfa.2740371109
  • Wet-heat-induced disulfide cross-linking and reduced digestibility: Duodu, Taylor et al., Properties of Heat-Treated Sorghum and Maize Meal and Their Prolamin Proteins, J. Agric. Food Chem. (2009); review of mechanisms in Sorghum Starch and Protein Digestibility, Foods (2026).
  • Yang et al. (2024). Structural and physicochemical characteristics of starches from sorghum varieties with varying amylose content. Food Science & Nutrition. doi:10.1002/fsn3.4245
  • Yang, Q., Zhang, W., Li, J., Gong, X., & Feng, B. (2019). Physicochemical Properties of Starches in Proso (Non-Waxy and Waxy) and Foxtail Millets (Non-Waxy and Waxy). Molecules 24(9), 1743. Onset 64.6–71.1 °C, conclusion 76.3–82.3 °C across four starches. doi:10.3390/molecules24091743

Sorghum malting and brewing science​

Other literature​

  • Kansas Living (5 August 2025). Milo makes an impact on every step of Kansas' food supply chain.
  • NOAA Regional Climate Centers, Applied Climate Information System (ACIS): station monthly precipitation 2000–2025, 1991–2020 monthly normals, and daily minimum temperatures 1991–2020, retrieved 29 September 2026. Autumns over 5 inches count September plus October totals in years with complete records; the first freeze is the first minimum of 32 °F (0 °C) or lower on or after July 1, in years missing no more than 10 days. Both are our calculations.

Also surveyed, without one citable document: SABS/SANS 235 and the ASBC, IoB, and EBC malt-analysis method systems, treated with full context in the Evaluation Methods survey.

Industry and supplier documentation​

  • Enzyme manufacturer technical data sheets and brewing guidance for the exogenous enzyme systems the protocols use (Termamyl, Ondea Pro, and glucoamylase families) — cited by class on the process pages; product names churn, declared activities are the durable reference.
  • Brewers Association craft-brewing statistics (2017).

Key terms​

A starting glossary — the terms most likely to be read loosely elsewhere. This is a stub; it will grow.

TermWorking definition
Truly gluten-freeBrewed from gluten-free grains from the start — never barley, wheat, rye, or oats. The house standard here.
Gluten-reducedBrewed with gluten grains, then treated to lower detectable gluten. A different promise; not the same market.
External (exogenous) enzymesEnzymes added to the mash to do the conversion sorghum malt's own enzymes cannot reliably carry. "Malt for character, external enzymes for conversion."
LiquefactionThe hot step that opens starch and thins the mash so downstream conversion has a fair chance.
Diastatic powerA malt's native enzyme capacity. Here it characterizes a malt lot; it is not a release gate, because conversion is external.
Pre-fermentation evidenceThe supplier, intake, malt, and process records gathered before fermentation — what a truly gluten-free claim actually rests on, since fermentation makes gluten hard to detect.
MRI indexIn the market data, 100 = the national average for a behavior; above 100 means it concentrates in that group or region.

An open reference​

Gluten Free Brewer is meant to be a working, open resource for brewers, maltsters, suppliers, researchers, and serious gluten-free beer people. If something here is wrong, unclear, or out of date, that's worth fixing — get in touch.