Testing & Certification Research Directory
This is the output layer of the whole directory, and the one where the science is least settled. The standard immunoassays were designed for intact gluten in unfermented food; beer is fermented and its proteins partly hydrolysed, which is exactly the condition those methods handle worst. That single unresolved question sits underneath labelling law, certification schemes, and the distinction between gluten-free and gluten-reduced that this site was built to defend.
The institutional layer is unusually rich: testing laboratories, certification bodies, methods organizations, national regulators, and the proteomics groups arguing the immunoassay world's results are incomplete.
How to read it: the same categories as the sorghum directory, with the same rules. Entries are brief, factual, dated, and linked to primary sources. Descriptions are not endorsements — and nothing here is regulatory advice.
Coverage is US-centered by design, with international anchors where the standards are foundational.
Directory established 2026-08-25 · first verification pass 2026-08-26.
Key topics — find entries by subject, across every category
How to read it: each topic lists the entries that touch it, so a reader hunting one subject can jump straight to the right sections.
Start here — why the test cannot carry the claim. Fermentation fragments gluten into peptides sandwich assays were not built to count; a beer can pass and still contain celiac-immunoactive peptides. FDA's own scientists documented this while FDA sets the threshold (Literature, Contributors, How the field connects).
The method of record — AOAC 2012.01, the R5 competitive ELISA written for fermented products, the kits built on it, and the R5-versus- G12 antibody question underneath every gluten number (Literature, Labs & Schemes).
Test the grain, not the beer — the four-provider network this site already uses: FGIS for sampling, a state seed lab for germination, FARRP for allergen certification on pre-fermentation inputs, and finished-beer panels at the end (Labs & Schemes, How the field connects).
Two agencies, two vocabularies — FDA governs food labeling, TTB governs beer, and TTB rulings decide why "gluten-free" and "gluten-removed" are separate claims in the United States (Standards & Regulators, Literature).
Provenance as the answer — if measurement is unreliable, confidence comes from knowing what the lot was: this site's Lot Reporting Standard and the two proposed standards behind it (Projects, Literature).
1. Institutions — federal labs, universities, and international centers doing the work
Drawn from the work cited in this page's Literature section.
— US federal —
FDA — Center for Food Safety and Applied Nutrition (CFSAN). Author of the gluten-free labeling rule that sets the 20 ppm threshold, and — through Garber's group — of the research showing why that threshold is hard to measure in a fermented product. The same agency writes the rule and documents the difficulty of enforcing it. FDA Q&A · Verified 2026-08-26
Alcohol and Tobacco Tax and Trade Bureau (TTB). The agency with authority over most beer labeling in the United States, and the reason "gluten-free" and "gluten-removed" are separate claims here. TTB Ruling 2020-2 · Verified 2026-08-26
USDA — Federal Grain Inspection Service (FGIS). The federal sampling standard for grain, and the upstream half of any gluten claim: what was sampled, and how. Our page on it · Verified 2026-08-26
— Mass spectrometry —
CSIRO — Commonwealth Scientific and Industrial Research Organisation, Australia. Institutional home of the Colgrave group's LC-MS/MS work on hordeins in beer, including the false-negative finding that this page's central caution now rests on. The 2014 paper · Verified 2026-08-26
— Methods and standards bodies —
AOAC International. Publisher of the Journal of AOAC International, which carries both Allred papers — the patient-antibody comparison and the visual-examination method. The venue where analytical methods for this problem are validated. AOAC · Verified 2026-08-26
The Prolamin Working Group (PWG). Founded 1985 at the University of Leiden by Professor Wim Hekkels. Thirteen executive members spanning paediatric and adult gastroenterology, immunology, biochemistry, plant science, food chemistry and gluten analysis. Holds observer status at Codex Alimentarius since 1999, works with AOAC International and the Cereals & Grains Association on ELISA development and validation, and produces the PWG-gliadin reference material that gluten methods are calibrated against. Put plainly: the body that supplies the standard everyone else's numbers are measured from. Recent progress and recommendations · Verified 2026-08-26
Technical University of Munich (TUM). Institutional home of Katharina Scherf, lead author of the Prolamin Working Group's statement on determining gluten in fermented foods. TUM also reaches this directory through Weihenstephan on the enzyme and yeast pages. The statement · Verified 2026-08-26
American Society of Brewing Chemists (ASBC). Founded 1934; its official methods are the analytical reference brewing measurements are reported against. ASBC · Verified 2026-08-26
Codex Alimentarius Commission. The international standard behind the 20 ppm figure that national rules adopt. Codex · Verified 2026-08-26
2. Contributors — the researchers behind the work
— The fermentation-breaks-measurement line —
Eric A.E. Garber — FDA CFSAN. Senior author on both the 2015 study tracking gluten through brewing and fermentation and the 2019 treatment of fermented-hydrolysed foods generally. The federal scientist who documented why the federal threshold is hard to measure in beer. The 2019 paper · Verified 2026-08-26
Rakhi Panda — FDA. Lead author on both Garber-group papers. doi:10.4315/0362-028X.JFP-14-546 · Verified 2026-08-26
H.F. Zoerb, C.Y. Cho and L.S. Jackson. Co-authors on the 2015 study following the analyte through brewing rather than testing the finished beer alone. The 2015 study · Verified 2026-08-26
Michelle L. Colgrave — CSIRO. Lead author of the mass-spectrometry work showing hydrolysed hordein fragments suppress their own ELISA measurement, and of the earlier ELISA-versus-MS comparison. The analytical chemist who established that the standard method can read backwards on this matrix. PubMed 25454134 · Verified 2026-08-26
H. Goswami and M. Blundell. Co-authors on the 2014 false-negatives study. PubMed 25454134 · Verified 2026-08-26
Katharina A. Scherf — Technical University of Munich. Lead author of the Prolamin Working Group's 2021 statement on determining gluten in fermented foods containing partially hydrolysed gluten — the scientific community's formal answer to the FDA's concession that no valid method exists. The statement · Verified 2026-08-26
Peter Koehler. Senior author on the same statement and a long-standing figure in prolamin analysis and reference-material work. The statement · Verified 2026-08-26
Wim Hekkels — University of Leiden. Founded the Prolamin Working Group in 1985, creating the body that now supplies the reference material behind gluten measurement worldwide. PWG background · Verified 2026-08-26
Frits Koning, Carlo Catassi, Fernando Chirdo, Riccardo Troncone, Detlef Schuppan and colleagues. The clinical and immunological half of the PWG statement's fourteen-author list — gastroenterologists and immunologists co-signing an analytical-methods position, which is unusual and tells you the question is not purely a chemistry one. The statement · Verified 2026-08-26
Laura K. Allred. Author on both the 2017 celiac patient antibody response study and the 2018 visual-examination method — the two halves of the problem, biological and procedural. doi:10.5740/jaoacint.16-0184 · Verified 2026-08-26
Cynthia Kupper & A. Quinn. Co-authors on the 2018 visual examination work on gluten-containing grains in gluten-free lots. doi:10.5740/jaoacint.170414 · Verified 2026-08-26
A. Real and colleagues. Authors of the 2014 PLOS ONE paper identifying celiac-immunoactive peptides in a beer that presented as gluten-free — the finding that makes this page's caution necessary rather than theoretical. doi:10.1371/journal.pone.0100917 · Verified 2026-08-26
3. Projects & Grants — funded work in flight right now
What qualifies: funded work a reader could pursue or follow, and the standards work currently in progress.
— This site's own standards work —
The Lot Reporting Standard. Active proposal: a lot's brewing behaviour is predicted by numbers the seller already holds, and the standard moves those numbers with the grain. The measurement problem this page maps is what it exists to answer. The standard · Verified 2026-08-26
The Truly Gluten-Free Standard (proposed). What a gluten-free claim should require beyond a passing test — written against the finding that a beer can test clean and still carry immunoactive peptides. The proposal · Verified 2026-08-26
The Sorghum Malt Evaluation Standard (proposed). A malt specification built for brewing rather than for diastatic power alone. The proposal · Verified 2026-08-26
— US funding this work could be taken to —
USDA NIFA — AFRI. The largest US competitive agricultural grants programme; its Food Safety, Nutrition and Health priority area covers analytical method development for a food-safety threshold. AFRI · Verified 2026-08-26
USDA NIFA — SBIR/STTR. The small-business route, and the realistic one for a lab or brewery rather than a university. SBIR/STTR · Verified 2026-08-26
ASBC Foundation — project funding. Grants toward brewing science including new analytical methods — the most direct fit on this page. ASBC · Verified 2026-08-26
Brewers Association — Craft Beer Research and Service Grants. Funds brewing-science research directly. The programme · Verified 2026-08-26
4. Funders & Programs — who pays for it (described, never endorsed)
Described, never endorsed.
— US federal —
FDA. Funds the CFSAN research that documented why gluten measurement fails in fermented products — the agency paying for the science that complicates its own rule. FDA Q&A · Verified 2026-08-26
USDA NIFA. Federal competitive agricultural research funding, including analytical and food-safety work. NIFA · Verified 2026-08-26
USDA FGIS. Federally maintained grain inspection infrastructure — public capacity a brewery can use without owning it. Our FGIS page · Verified 2026-08-26
— Industry and society —
ASBC Foundation. The society's funding arm, supporting method development and graduate students. ASBC · Verified 2026-08-26
Brewers Association. Industry-funded research money aimed at beer rather than at a crop. The association · Verified 2026-08-26
Pennsylvania Malt and Brewed Beverage Industry Promotion Program. The one US public funder in this directory whose scope is brewing itself. Program page · Verified 2026-08-26
USDA NIFA — SBIR/STTR. The small-business route for a laboratory or kit developer rather than a university. SBIR/STTR · Verified 2026-08-26
National Institutes of Health. Celiac disease research funding. The antibody methods this page runs on originate in clinical immunology, and the patient-response work Allred published sits at that boundary. NIH · Verified 2026-08-26
Beyond Celiac and comparable patient research foundations. Disease- focused non-profits funding celiac research directly — the funding route closest to the people the 20 ppm threshold exists to protect. Beyond Celiac · Verified 2026-08-26
CSIRO — in-house research funding, Australia. Funded the mass spectrometry that established ELISA's suppression problem in beer. A foreign national laboratory produced the most consequential finding on this page. The 2014 paper · Verified 2026-08-26
— Patient-side —
Gluten Intolerance Group (GIG). Parent of GFCO, and the patient organisation whose certification programme funds the scheme this page describes. GIG · Verified 2026-08-26
5. Labs, Schemes & Industry — who tests and who certifies
Described, never endorsed; a listing is never a statement that a lab, panel or scheme is fit for a given purpose. A trained sensory panel is indexed here too — it is a test, differing from an assay only in that the instrument is human.
— The third-party network a small brewery actually uses —
Most gluten-free breweries have no laboratory and do not need one. The four providers below cover the chain from grain intake to packaged product, and this site documents the division of labour between them.
USDA Federal Grain Inspection Service (FGIS). Official, independent grain sampling and grading — test weight, moisture, damage, foreign material and mycotoxins. Its value is as much in how the sample is drawn as in what the lab reports. Our page · Verified 2026-08-26
FARRP — Food Allergy Research & Resource Program, University of Nebraska. Allergen and gluten testing with certification below roughly 3 ppm, applied to pre-fermentation inputs: grain and malt. Testing where the analyte is still intact. Testing resources · Verified 2026-08-26
North Dakota State Seed Lab. Germination and purity of the grain lot. Bard's ran germination through both the state seed lab and FGIS — two independent reads on the same question. Testing resources · Verified 2026-08-26
White Labs. Finished-beer analytical panel and microbiology — gravity, ABV, attenuation, colour, pH, IBU, diacetyl, wild yeast and bacteria. The packaged-product end of the chain. Testing resources · Verified 2026-08-26
— Assay and kit makers named in this site's own work —
Neogen. Gluten and allergen test kits; appears across this site's quality pages. Our testing methods page · Verified 2026-08-26
R-Biopharm. The RIDASCREEN gluten assay line, including the R5 antibody methods that most gluten claims rest on. R-Biopharm · Verified 2026-08-26
Megazyme. Assay kits for brewing and cereal measurements; the measurement house shared with this directory's enzyme wing. Internal enzymes · Verified 2026-08-26
— The kit makers —
Three companies supply most of the antibodies behind gluten numbers in this category. Described, never endorsed.
R-Biopharm. Manufacturer of RIDASCREEN Gliadin (R7001), the R5 kit that AOAC 2012.01 is built on and that Codex treats as the type 1 method. The reference against which the others are compared. The product · gluten test range · Verified 2026-08-26
Neogen. Supplies an alternative kit using the same R5 monoclonal antibody as the reference method. Our testing methods page · Verified 2026-08-26
Romer Labs. The third kit line, compared against the R5 Codex type 1 method in the published comparisons above. The kit comparison · Verified 2026-08-26
— Mass spectrometry as a service —
LC-MS/MS peptide quantification. Not a product but a capability: contract analytical laboratories running targeted peptide MS can measure what ELISA suppresses. It is more expensive, less standardised and not the method of record — and it is the only approach shown to detect what the reference method misses in beer. The evidence · Verified 2026-08-26
— What testing actually costs —
Bootleg Biology. Publishes gluten ELISA assay pricing openly — $44.99 to $299.99 with one-to-three business day turnaround. The clearest public figure we have found for what a small producer pays. The service · Verified 2026-08-26
White Labs — gluten ELISA. R5-competitive gliadin assay as a service, with bulk pricing. The service · Verified 2026-08-26
Hygiena — GlutenTox competitive G12. A competitive ELISA built on the G12 antibody rather than R5 — the alternative antibody, sold as a kit. Testing methods · Verified 2026-08-26
R-Biopharm — brewery guidance. The reference-kit manufacturer publishes a practical guide for breweries, which is where much of this category's working knowledge of the method actually lives. The guide · Verified 2026-08-26
— Certification schemes —
Gluten-Free Certification Organization (GFCO). The most widely recognised US third-party gluten-free mark. GFCO · Verified 2026-08-26
6. Standards, Regulators & Events — the methods bodies, the rule-makers, and the field's calendar
— US regulators —
FDA. Sets and interprets the gluten-free labeling rule for foods. FDA Q&A · Verified 2026-08-26
TTB. Governs beer labeling and advertising, including what may be said about gluten. Ruling 2008-3 determines which products fall under its authority at all. Ruling 2008-3 · Verified 2026-08-26
— Certification schemes —
Gluten-Free Certification Organization (GFCO). The most widely recognised US third-party gluten-free certification mark. Described, never endorsed. GFCO · Verified 2026-08-26
Gluten Intolerance Group (GIG). GFCO's parent organisation, and the patient-facing body behind it. GIG · Verified 2026-08-26
Codex Alimentarius — type 1 method designation. Codex names the R5 ELISA as the type 1 method for gluten, which is what makes one manufacturer's antibody the international reference. Codex · Verified 2026-08-26
European Brewery Convention (EBC). Founded 1946; since the 2007 merger, the scientific and technical arm of The Brewers of Europe. Publishes Analytica-EBC — over 240 analytical methods covering raw materials through packaged beer — and defines the EBC colour and haze units used internationally. The European counterpart to ASBC's methods, and the other half of any serious methods comparison. EBC · The Brewers of Europe · Verified 2026-08-26
Cereals & Grains Association. Works with AOAC International and the Prolamin Working Group on validating gluten methods — the cereal-science corner of the methods-validation network, alongside the analytical-chemistry corner (AOAC) and the clinical one (PWG). PWG background · Verified 2026-08-26
Gluten Free Watchdog. Patient-facing advocacy organisation that publishes independent product testing and contests scientific and regulatory positions in public — including the PWG statement indexed above. The organisation · Verified 2026-08-26
— Methods bodies —
AOAC International. Validates the analytical methods this subject depends on. AOAC · Verified 2026-08-26
ASBC. Official methods for brewing analysis. ASBC · Verified 2026-08-26
Codex Alimentarius. The international 20 ppm standard. Codex · Verified 2026-08-26
— Events —
ASBC Annual Meeting. Where analytical method work on brewing is presented. ASBC · Verified 2026-08-26
7. Literature & Datasets — the anchor works, the methods, and the published data
— Why fermentation breaks the measurement —
This is the page's central problem, and it is well documented. Gluten in beer is fragmented by fermentation into peptides that antibody tests were never built to count.
Panda, Zoerb, Cho, Jackson & Garber (2015), Detection and Quantification of Gluten during the Brewing and Fermentation of Beer Using Antibody-Based Technologies. Journal of Food Protection. Tracks what happens to the analyte through the process rather than testing only the finished product — the study that shows when in brewing the measurement starts to fail. doi:10.4315/0362-028X.JFP-14-546 · Verified 2026-08-26
Panda & Garber (2019), Detection and Quantitation of Gluten in Fermented-Hydrolyzed Foods by Antibody-Based Methods. Frontiers in Nutrition. The general statement of the problem across fermented and hydrolysed foods, of which beer is the hardest case. doi:10.3389/fnut.2019.00097 · Verified 2026-08-26
Real et al. (2014), Identification and in vitro reactivity of celiac immunoactive peptides in an apparent gluten-free beer. PLOS ONE. The finding that gives this page its stakes: a beer that tested as gluten-free still contained peptides reactive to celiac immune response. "Apparent" is doing the work in that title. doi:10.1371/journal.pone.0100917 · Verified 2026-08-26
Allred et al. (2017), The Celiac Patient Antibody Response to Conventional and Gluten-Removed Beer. Journal of AOAC International. Tests the question against patient antibodies rather than against a kit — the closest thing the field has to a biological reference method. doi:10.5740/jaoacint.16-0184 · Verified 2026-08-26
— The finding that inverts the safety logic —
Colgrave, Goswami, Blundell et al. (2014), Using mass spectrometry to detect hydrolysed gluten in beer that is responsible for false negatives by ELISA. Journal of Chromatography A. This is the most consequential paper on this page. Using LC-MS/MS with multiple reaction monitoring on whole beer and two fractions — hydrolysed hordeins under 30 kDa and peptide fragments under 10 kDa — the authors found B- and D-hordein particularly prone to hydrolysis, and then found something worse than under-detection: beers containing high levels of B-hordein fragments gave near-zero ELISA values, and the persisting fragments produced a dose-dependent suppression of the ELISA measurement — even when the assay was calibrated against a hordein standard.
Read that carefully. It does not say the test misses hydrolysed gluten. It says the hydrolysed gluten actively suppresses its own measurement: the more of it a beer contains, the lower the number comes back. A more contaminated beer can test cleaner than a less contaminated one. Every gluten claim resting on ELISA alone inherits that inversion. PubMed 25454134 · Semantic Scholar · Verified 2026-08-26
Measuring hordein (gluten) in beer — a comparison of ELISA and mass spectrometry. The head-to-head that frames the 2014 result: two methods, the same beers, different answers. PubMed 23509606 · Verified 2026-08-26
Detection and Quantitation of Gluten in Fermented-Hydrolyzed Foods by Antibody-Based Methods: Challenges, Progress, and a Potential Path Forward. The field's own assessment of where antibody methods stand and what would replace them. PMC6611335 · Verified 2026-08-26
A multiplex competitive ELISA for the detection and characterization of gluten in fermented-hydrolyzed foods. Analytical and Bioanalytical Chemistry. One answer to the suppression problem — measure several epitopes at once rather than trusting a single antibody. doi:10.1007/s00216-017-0677-z · Verified 2026-08-26
LC-MS/MS Reveals Hordeins Are Enriched in Brewers' Spent Grain. Journal of the American Society for Mass Spectrometry. Where the hordein goes if it does not stay in the beer — relevant to any brewery handling both gluten and gluten-free streams. The paper · Verified 2026-08-26
— The regulator's concession, and the argument that followed —
FDA final rule on compliance methods for fermented, hydrolysed and distilled foods labelled "gluten-free" (published 13 August 2020; 21 CFR 101.91). The premise is the striking part. The agency's reason for the rule is that "the current gluten tests do not adequately detect and quantify gluten in fermented and hydrolyzed foods or ingredients" — so instead of an assay threshold it requires records: test results, certificates of analysis or other verification for the food or each ingredient, kept at least two years after the food enters interstate commerce and produced on inspection. It does not change the definition of gluten-free; it changes what proving it means. FDA Q&A · Verified 2026-08-26
Scherf, Catassi, Chirdo, Ciclitira, Feighery, Gianfrani, Koning, Lundin, Masci, Schuppan, Smulders, Tranquet, Troncone & Koehler (2021), Statement of the Prolamin Working Group on the Determination of Gluten in Fermented Foods Containing Partially Hydrolyzed Gluten. Frontiers in Nutrition 7:626712. The field's formal response to the FDA rule, from the body that makes the reference material. PMC7835721 · PubMed 33511151 · Verified 2026-08-26
Gluten Free Watchdog — objection to the Prolamin Working Group statement. A patient-advocacy organisation publicly contesting the PWG's position. Indexed because this page's subject has a live dispute running between a regulator, a scientific working group and the advocates for the people the threshold protects, and a reader deserves to meet all three rather than one. The objection · Verified 2026-08-26
Recent Progress and Recommendations on Celiac Disease From the Working Group on Prolamin Analysis and Toxicity. The PWG's standing review of where analysis and toxicity research sit, and the source for its composition, Codex status and reference-material role. PMC7090026 · Verified 2026-08-26
Preparation and characterization of enzymatically hydrolyzed prolamins from wheat, rye and barley as references for immunochemical quantitation of partially hydrolyzed gluten. Analytical and Bioanalytical Chemistry. The problem underneath everything else on this page: you cannot calibrate against hydrolysed gluten until somebody makes hydrolysed gluten standards. The paper · Verified 2026-08-26
Who regulates a gluten-free beer: FDA or TTB. The FDA's own answer, and it is unusually direct — beers meeting the malt beverage definition in the Federal Alcohol Administration Act (27 U.S.C. 211(a)(7)) fall to TTB; other beers fall to FDA, and the example the agency gives is sorghum beer. Most of this directory's subject matter therefore sits under FDA labeling rules rather than TTB's, which is not what a brewer coming from barley would assume. FDA Q&A · Verified 2026-08-26
21 CFR 101.91(c)(2)–(4) — the record-keeping requirement. Applies even to inherently gluten-free foods: a brewer using no gluten-containing grain at all must still make and keep records giving adequate assurance for a gluten-free claim, because the food is fermented. The extent of records expected varies with cross-contact risk — more for grains and legumes, less for dairy — which is a regulator grading evidence by ingredient category. FDA Q&A · the lot reporting standard · Verified 2026-08-26
— The method of record —
AOAC Official Method 2012.01 — Partially Hydrolyzed Gluten in Fermented Cereal-Based Products by R5 Competitive ELISA. The method written for exactly this problem. Brewing hydrolyses gluten, so a sandwich ELISA under-reads it; the competitive format uses a monoclonal antibody against celiac-toxic peptide fragments instead. Adopted by AOAC in 2012 as First Action, combining RIDASCREEN Gliadin with Cocktail extraction. Proficiency and method background · Verified 2026-08-26
Gluten in Beers: Evaluation of Reproducibility of the R5-Based Competitive ELISA Method Using Real Samples (2023). Reproducibility of the method of record, tested on actual beers rather than spiked standards. doi:10.3390/proceedings2023091354 · Verified 2026-08-26
Gluten Assessment in Beers: Comparison by Different Commercial ELISA Kits and Evaluation of NIR Analysis as a Complementary Technique. Different kits on the same beers, plus near-infrared as a second channel — the practical question of whether the answer depends on which kit you bought. PMC8224778 · Verified 2026-08-26
Comparison of R5 and G12 Antibody-Based ELISA for Gluten Content in Official Food Samples. The two competing antibodies compared on official samples — the choice underneath every gluten number. The comparison · Verified 2026-08-26
Measurement of Gluten in Food Products: Proficiency Testing. European proficiency-testing rounds documenting consistency between laboratories running the same method. The chapter · Verified 2026-08-26
Characteristics and Immunogenicity of Gluten Peptides in Enzyme-Treated and -Untreated Beers for Celiac Patients (2024). Fermentation 10(6):277. The follow-up to Real: the same question asked of enzyme-treated beers specifically — the products the "gluten-removed" label covers. doi:10.3390/fermentation10060277 · Verified 2026-08-26
Barley based gluten free beer — a blessing or an uncontrollable risk? The category-level version of the question, asked plainly. PMC11581983 · Verified 2026-08-26
G12 and A1 anti-33-mer antibodies with preparative HPLC. The third analytical route: rather than counting gluten, identify the specific immunoactive peptides and confirm them against celiac patient cells. Real's method, and arguably the one closest to the question that matters. The PLOS ONE paper · Verified 2026-08-26
— Sampling and inspection —
Allred, Kupper & Quinn (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. The upstream half of the problem: what an inspector can establish by looking, before any assay runs. doi:10.5740/jaoacint.170414 · Verified 2026-08-26
— The regulatory instruments —
FDA — Gluten-Free Food Labeling Final Rule. The 20 ppm threshold and the questions-and-answers guidance interpreting it. FDA Q&A · Verified 2026-08-26
TTB Ruling 2008-3 — classification of brewed products as beer. Determines which products fall under TTB rather than FDA authority, and therefore which labeling regime applies at all. The ruling · Verified 2026-08-26
TTB Ruling 2020-2 — gluten content statements in labeling and advertising. The current TTB position on what a beer may say about gluten, and the reason "gluten-removed" and "gluten-free" are not interchangeable claims in the United States. The ruling · Verified 2026-08-26
— This site's own standards and working pages —
The Lot Reporting Standard. This site's proposed standard: a lot's brewing behaviour is predicted by numbers the seller already holds, and the standard moves those numbers with the grain. The standard · Verified 2026-08-26
The Truly Gluten-Free Standard (proposed). The site's position on what a gluten-free claim should require beyond a passing test. The proposal · Verified 2026-08-26
The Sorghum Malt Evaluation Standard (proposed). A malt specification built for brewing rather than for diastatic power alone. The proposal · Verified 2026-08-26
Gluten testing methods — this site's working page. What each method actually proves, and where fermentation breaks the measurement. The page · Verified 2026-08-26
LCBO finished-beer certificates. Third-party certificates of analysis on finished gluten-free beer, published as data. The dataset · Verified 2026-08-26
The production QA log, 2014–2017. A multi-year commercial QA record from this site's own production history. The log · Verified 2026-08-26
Gluten-reduced beer survey (2015). Survey data on how the category's consumers respond to gluten-reduced products — the demand-side evidence behind the labeling question. The survey · Verified 2026-08-26
How the field connects — documented links between the entries above
Every connection carries its own evidence link — no inferred relationships, no speculation.
The reference method is one company's antibody. Codex names the R5 ELISA as the type 1 method; AOAC 2012.01 is built on RIDASCREEN Gliadin with Cocktail extraction. The international standard for gluten therefore rests on a specific manufacturer's monoclonal antibody — which is normal in analytical chemistry and worth stating plainly rather than leaving implicit. The method background · the kit
Two antibodies can give two answers. R5 and G12 target different peptide sequences and have been compared on official food samples. Which antibody a laboratory uses is a methodological choice that precedes every gluten number a brewery receives — and it is rarely stated on a certificate. The comparison
The competitive format exists because the sandwich format fails here. A sandwich ELISA needs two intact binding sites on one fragment. Fermentation destroys that, so the method of record for beer counts fragments competitively instead. The assay's design is a direct consequence of what brewing does to the analyte. AOAC method background · the 2015 study
Kit choice may move the number more than lot choice does. Published comparisons run different commercial ELISA kits against the same beers. For a brewery near the threshold, the supplier of the test can matter as much as anything it did in the brewhouse. The comparison
A mash decision reaches this page. A protein stand at 45°C is reported to lower protein including gluten. That means a process and equipment choice can change a compliance result — and no certification scheme we have found asks what mash schedule was run. Process and equipment
Proficiency testing exists, and it is European. Regular PT rounds document consistency between laboratories running the reference method. We have found no equivalent US programme specific to gluten in beer, which leaves a US brewery's confidence resting on its lab's own participation. The chapter
Certification is a scheme, not a measurement. GFCO and comparable marks set thresholds and audit against them. The analytical problem this page documents sits underneath every such mark, and we have found no published account of how any scheme handles the fermented-matrix question. Our testing methods page
The regulator reached this site's conclusion first, and wrote it into the rule. The FDA's 2020 rule requires records rather than a finished-product assay for fermented foods, and gives as its reason that "the current gluten tests do not adequately detect and quantify gluten in fermented and hydrolyzed foods." Test the beer, get a number you cannot defend; document the grain, and you have what the regulator actually asks for. This site's lot reporting standard is not an alternative to compliance — it is the shape compliance already takes. FDA Q&A · the lot reporting standard
Being inherently gluten-free does not exempt you. A beer brewed from sorghum, rice or millet, with no gluten-containing grain anywhere near it, still falls under 21 CFR 101.91(c)(2)–(4) — because the requirement attaches to fermentation, not to the grain bill. Two years of records, per ingredient, produced on inspection. That is a compliance obligation on essentially every brewer this site is written for, and it follows from the process rather than the recipe. FDA Q&A · the lot reporting standard
Sorghum beer is the FDA's own example of a beer it regulates. Malt beverages go to TTB; beers outside that definition go to FDA, and the agency names sorghum beer as the case. So the gluten-free brewing category is disproportionately governed by the agency that concluded the gluten test does not work in fermented foods — the two facts land on the same brewers. FDA Q&A · FDA vs TTB labeling · TTB Ruling 2020-2
Codex and the FDA now rest on incompatible premises. Codex names R5 as the type 1 method for gluten. The FDA says no valid method exists for fermented foods. Both positions are current, and beer is a fermented food. A brewer selling into both regimes is answering to standards that disagree about whether the central measurement is possible. The PWG statement · gluten testing methods
The body that makes the reference material also argues the case. The Prolamin Working Group produces PWG-gliadin, the material gluten methods are calibrated against; holds Codex observer status; and published the formal response to the FDA rule. Reference material, standards influence and position-taking concentrated in one thirteen-member group is worth knowing when reading any of its outputs — and worth knowing that no comparable second source exists. PWG background
The people the threshold protects are contesting the science in public. Gluten Free Watchdog published an objection to the PWG statement. This page's subject is not a settled technical field with a lay audience — it is an open dispute with patients' advocates inside it. The objection
You cannot calibrate against hydrolysed gluten without hydrolysed gluten standards. Reference materials had to be made by enzymatically hydrolysing wheat, rye and barley prolamins before partially hydrolysed gluten could be quantified immunochemically at all. The measurement problem starts one step before the assay does. The reference-material work
Two continents, two method books, one beer. ASBC methods and Analytica-EBC both cover the same analyses and are not identical. A gluten-free brewer publishing a colour or haze figure is publishing it in one of two systems, and this directory indexes both precisely so a reader can tell which. EBC · gluten testing methods
The analyte suppresses its own measurement. This is the sharpest finding on the page and it inverts the intuition every gluten claim rests on. Hydrolysed hordein fragments persisting in beer do not merely escape the ELISA — they produce a dose-dependent suppression of the reading, so beers with high B-hordein fragment loads returned near-zero values. More of the thing being measured yields a smaller number. A brewery could, in principle, pass more comfortably as its contamination rises, and nothing on the certificate would show it. Colgrave et al. 2014 · the ELISA/MS comparison
The method of record and the method that works are not the same method. AOAC 2012.01 with R5 competitive ELISA is what regulation and certification run on. LC-MS/MS is what detects the fragments R5 under-reads. The field knows this — its own review is titled Challenges, Progress, and a Potential Path Forward — and the gap between the defensible method and the accurate one is where this page's whole caution lives. The review · multiplex approach
Not all hordein hydrolyses equally. B- and D-hordein were found particularly prone to it, which means the suppression effect depends on which barley proteins were present and how the process treated them — grain, mash schedule and fermentation all feeding into whether a test reads true. Colgrave et al. 2014 · process and equipment
One federal agency writes the rule and documents why it is hard to enforce. FDA sets the 20 ppm gluten-free threshold. FDA's own CFSAN scientists — Garber's group — published the work showing that fermentation fragments gluten into peptides antibody methods were not built to count. That is not two camps disagreeing; it is one agency holding both facts at once. The rule · the 2015 study · the 2019 review
A beer can pass the test and still contain what the test is for. Real et al. identified celiac-immunoactive peptides in a beer that presented as gluten-free. That single finding is why this page exists rather than simply pointing at a threshold: the number and the biology can disagree. The paper · our testing-methods page
Test the grain, not the beer — and this site's own network already does. FARRP certifies below roughly 3 ppm on pre-fermentation inputs: grain and malt, where the analyte is still intact and countable. FGIS samples the lot before that. By the time a finished beer reaches White Labs, the gluten question has already been decided upstream — what remains is confirmation, not measurement. The network · FGIS sampling
Two agencies, two vocabularies, one product. FDA governs food labeling; TTB governs most beer labeling and decided in 2008 which products fall under it at all. TTB Ruling 2020-2 is why "gluten-free" and "gluten-removed" are separate claims in the United States — a distinction created by regulatory structure rather than by chemistry. Ruling 2008-3 · Ruling 2020-2
Sampling beats testing, and it is the cheaper half. This site's own position is that how a sample is drawn matters as much as what the assay returns — which is why FGIS gets its own page. A perfect assay on an unrepresentative sample is worse than useless, because it produces a defensible-looking number. FGIS sampling · testing resources
The lot standard exists because the test cannot carry the claim. If fermentation breaks the measurement, then confidence has to come from provenance: what the lot was, who measured it, and when. This site's Lot Reporting Standard is the direct consequence of the analytical problem this page maps. The standard
A trained panel is a test, and belongs here. Sensory panels are indexed on this page rather than with flavor and texture, because a panel has a protocol, a reference standard and a reported result. It differs from an assay only in that the instrument is human — and it carries the same sampling and reproducibility problems. Flavor and texture
Research gaps — where the field's coverage runs out
This section said no regulator had acted on the suppression finding. That was wrong, and how it is wrong matters more than the error. On 13 August 2020 the FDA published a final rule establishing compliance methods for fermented, hydrolysed and distilled foods labelled gluten-free, and it named beer among them. Its stated reason: "the current gluten tests do not adequately detect and quantify gluten in fermented and hydrolyzed foods or ingredients." The agency did not merely acknowledge the measurement problem — it wrote a rule that does not rest on testing the finished product, and said it would revisit the regulation "if or when a scientifically valid method" becomes available.
The Prolamin Working Group published a formal statement in response; Gluten Free Watchdog published a public objection to that statement. The question is contested, not dormant.
What survives as a gap is narrower and sharper: Codex still names R5 as the type 1 method and AOAC 2012.01 remains the method of record, so an international standard and a US labeling rule now rest on incompatible premises about whether the central measurement works. And we have still found no regulatory document that engages the dose-dependent suppression result specifically — the FDA's position rests on inadequacy in general, not on the inversion Colgrave documented.
Three analytical routes exist and none has displaced the reference. R5 competitive ELISA is the method of record. LC-MS/MS detects what R5 suppresses. Preparative HPLC with G12/A1 anti-33-mer antibodies identifies immunoactive peptides specifically, and has been validated against celiac patient cells. Each answers a different question, and no regulator has replaced the first with either of the others. The gap is not an absence of methods — it is that the defensible method and the sensitive ones are still different methods.
This section previously said the peptide finding had not been followed up. It has been. Characteristics and Immunogenicity of Gluten Peptides in Enzyme-Treated and -Untreated Beers for Celiac Patients (2024) takes the question directly to the enzyme-treated products, and Barley based gluten free beer — a blessing or an uncontrollable risk? poses it at category level. Real's own method was stronger than summarised here too: peptides were identified by anti-gliadin 33-mer antibodies (G12 and A1) on a beer already below 20 ppm, and confirmed by activating peripheral blood mononuclear cells from fourteen celiac individuals with interferon-γ production. What is still missing is a market survey — how many commercially sold gluten-free or gluten-removed beers carry these peptides — rather than mechanism studies on selected samples.
Nobody has published a gluten-free brewing sampling standard. FGIS covers grain, and this site argues sampling matters more than assay choice — but we have found no sampling protocol written specifically for a gluten-free brewery's inputs and process steps.
The certification schemes' internal methods are not public. GFCO and comparable marks set thresholds and audit against them; we have found no published account of how they handle the fermented-matrix problem the FDA literature documents.
Cost was recorded here as undocumented. It is published, and it is low. Commercial gluten ELISA testing for beer is offered publicly in the $45–300 per assay range with one-to-three business day turnaround, and bulk pricing is offered on top of that. The number that decides whether a small producer tests is available and is not the barrier. What remains undocumented is the cumulative figure — what a brewery spends per lot across grain, malt, in-process and finished-beer checks over a year — which is the number a business plan actually needs.
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Entries are added as they are verified, never to pad the count. A listing here is a map reference, not a citation, and nothing here is regulatory or medical advice. Corrections welcome — see Contact.