Open questionWe do not have an answer. The ask is on this page.
Research Asks: Work the Field Can Move Forward
This is not our internal to-do list. It's the public list of work that would move gluten-free brewing forward, written specifically enough to act on. You don't need permission, credentials, or a relationship with us to take one. You need a kettle or a lab and the discipline to write down what happened.
How to respond: report the batch — a short form that asks for what makes a report usable. A useful report names what you changed, what you held steady, what you measured, and the result — including failures, which are often worth more than successes. Contributors get credit under whatever name they choose; results that contradict us are the most valuable kind.
The asks
Scale is not a gate. Each ask lists the minimum it takes to run — equipment, not identity. A homebrew kettle, a pilot system, a production floor, and a lab bench are welcome on every one of them, and the same experiment repeated at two scales is worth more than either result alone.
| # | Ask | Minimum it takes | Status |
|---|---|---|---|
| 1 | Hop varieties against sorghum malt | A split batch on any system, five gallons up | Open — seeking testers |
| 2 | Tavern Ale honey load and timing | One batch on any five-gallon system | Open — seeking testers |
| 3 | the Reliable Mash at homebrew scale | A recirculating homebrew system | Open — seeking testers |
| 4 | the Maltose Mash against the Reliable Mash | Any system that can hold 132°F for 100 minutes | Open — seeking testers |
| 5 | Run the proposed evaluation standard | A malt-analysis bench — commercial, university, or serious amateur | Open — seeking review |
| 6 | How far can enzyme doses come down? | Repeated batches at a consistent scale | Open |
| 7 | How far can the 190°F baseline come down? | Multiple batches across multiple malt lots | Open |
| 8 | Sorghum malt data from anywhere | A filing cabinet | Open |
| 9 | Screen sorghum cultivars for brewing enzyme activity after standardized malting | A malting bench and an enzyme assay — a lab, a university, or a maltster with a partner lab | Open |
| 10 | The calcium ladder: what does the mash actually need? | A homebrew system and water salts | Open |
| 11 | Can anything close sorghum's FAN gap, and at what cost? | A system that holds a rest temperature, plus FAN analysis — a lab partner or university bench | Open |
| 12 | Where is the rice-hull floor? | Any all-grain system, five gallons up | Open |
| 13 | Koji-inoculated sorghum malt on an all-malt grist | A malting bench that can inoculate, and a brew of any size against the uninoculated control | Open — seeking review |
| 14 | Walk through the door the practitioner fund already opened | A membership, a proposal, and one of the asks above | Open — seeking testers |
| 15 | Attenuation, measured on the wort we actually brew | One strain, two worts, on any system with a hydrometer | Open — seeking testers |
| 16 | Fermentation temperature on this beer | A split fermentation at two setpoints | Open — seeking testers |
| 17 | Malt buckwheat cultivars and publish the table | A micro-malting bench and six named cultivars | Open — seeking testers |
| 18 | What diastatic power is actually enough to self-convert? | A mash bench, one malt lot, and no exogenous enzymes | Open |
| 19 | Reconcile the sorghum alpha-amylase methods | One malt sample, two laboratories, two named methods | Open |
| 20 | Does late-season cold move sorghum grain protein? | Grain from one cultivar across seasons, with weather records | Open |
Ask 1 — hop varieties against sorghum malt
The question. Do some hop varieties genuinely clash with sorghum malt, or is that impression an artifact of the beers we happened to brew?
Why it matters. Twenty years of commercial brewing produced a consistent field impression — German varieties integrated well, Saaz clashed — that has never been tested. If it's real, it changes hop selection for every gluten-free brewer. See Hops and Yeast for Sorghum Malt.
What would count. One 100% sorghum malt wort, split, each half bittered and finished with a different variety, everything else held steady. Tasting notes from more than one palate. Two or three independent reports would settle it.
A measured alternative exists. Gesho (Rhamnus prinoides), the Ethiopian bittering plant, has been characterised as a hop substitute: total resin 15.96 to 16.02%, iso-alpha-acid 1.17 to 1.45 mg/L, alpha-acid 1.44 to 1.92 mg/L, essential oil 3.0 to 3.07%, with the authors finding its bittering composition comparable with hop (Flavor and Sensory directory). Nobody has run it against sorghum malt as of September 2026 — it has been brewed into barley malt beer in Ethiopia at up to half the hop load — and the split-wort design above would take it as one arm.
Pages. Where this ask's card appears: Hops and Yeast for Sorghum Malt · American Golden Lager · Oktoberfest Amber Lager · Tavern Ale · Yeast strain volatiles
Ask 2 — Tavern Ale honey load and timing
The question. How much honey, added when, produces the balance in Tavern Ale Version A?
Why it matters. It's the one number that was never recorded in a beer worth reconstructing — and honey timing (flameout vs whirlpool vs fermenter) changes whether it reads as aroma, sweetness, or nothing.
What would count. Brew version A at 1 lb, 2 lb, and 3 lb per 5 gallons — or split one batch across honey timings — and report where the balance lands. A version that beats ours gets published as version B with your name on it.
Pages. Where this ask's card appears: Tavern Ale
Ask 3 — the Reliable Mash at homebrew scale
The question. Does our production protocol actually work at 5 gallons, and where does it break?
Why it matters. The translation is arithmetic on a production process, and arithmetic isn't a brew day. Nobody has validated it.
What would count. Efficiency, mash behavior, runoff time, gravity, fermentation curve, and what you'd change — plus your equipment description, so results are comparable.
Pages. Where this ask's card appears: The Reliable Mash at homebrew scale · Mash methods · Old Traditional Bard's · Hot Amylex · SEBAmyl · Craig's Hybrid · Your first batch
Ask 4 — the Maltose Mash against the Reliable Mash, on a split wort
The question. Does a protease rest plus a fungal-alpha coolback produce a materially better beer from sorghum malt than the glucoamylase finish — and why did Bard's abandon it?
Why it matters. the Maltose Mash was written and played with at Bard's; the Reliable Mash won, and the reasons were never recorded. Everything downstream of wort sugar profile — fermentation behavior, body, drinkability — rides on this.
What would count. Same recipe, same malt, the Reliable Mash vs the Maltose Mash, side by side. FAN, wort sugar profile (HPLC if you can get it), fermentation curves, and honest sensory comparison. A documented failure is as useful as a success here.
Pages. Where this ask's card appears: The Maltose Mash · The Maltose Mash at homebrew scale · Old Traditional Bard's · Oktoberfest Amber Lager
Ask 5 — run the proposed evaluation standard
The question. Does the external-enzyme reference mash in GFB-SME work as a practical evaluation method?
Why it matters. The field evaluates sorghum malt with instruments built for other questions. A proposal nobody runs is just an opinion in a nicer font.
What would count. A lab running the reference mash on two or more malts and reporting friction — what was ambiguous, what wouldn't reproduce, what should change. Criticism is the deliverable.
Who could answer this. Melinda Yerka's group at the University of Nevada, Reno, whose method work the draft standard already cites; the Montana State University malt quality lab, which runs the panel (Researchers; Labs and Certifiers).
Pages. Where this ask's card appears: The proposed standard · Madison screening · 2002 to 2004 screenings · USDA 2023 protein NIR
Ask 6 — how far can enzyme doses come down?
The question. Our published doses are conservative production insurance. How much can be removed before conversion, runoff, or fermentation suffer?
Why it matters. Enzymes are a real line item. If half the dose works, that's money back for every gluten-free brewer — and nobody has published the curve for this malt and system; two exist for other substrates (Open Problems).
What would count. Staged reduction across batches on one malt and system, tracking conversion, iodine result, runoff, gravity, and attenuation. Report the point where something broke.
Who could answer this. Elke Arendt's group at University College Cork, which ran the enzyme dose-response surface on buckwheat malt (Researchers).
Pages. Where this ask's card appears: The Reliable Mash · External Enzymes
Ask 7 — how far can the 190°F baseline come down?
The question. The 190°F, 60-minute hold is deliberately conservative — 30 minutes worked in most runs. Where is the real boundary?
Why it matters. The extra thirty minutes is insurance bought without knowing its price. It costs energy, tank time, and throughput on every batch anyone runs, and it is the first thing a brewer at scale will question. We hold it because the boundary has never been established, not because we have evidence a shorter hold fails. Settling it would either retire a conservative default or turn it into a measured one, and either is worth more than the current answer.
What would count. Controlled alternatives across multiple batches and multiple malt lots, judged on liquefaction, viscosity, iodine, extract, runoff, fermentation, and repeatability. One clean batch is encouraging; it isn't a baseline.
Pages. Where this ask's card appears: The Reliable Mash · Why the 190°F baseline exists
Ask 8 — sorghum malt data from anywhere
The question. What else exists? Screening data, malt analyses, brewing trials, failed programs, dusty spreadsheets from a project that ended.
Why it matters. We published every dataset we have cleared for release because the published North American record is nearly empty. Ours can't be the only surviving data. Some records are still in review and a few are held for reasons we will state if asked — the claim is what we could publish, not everything in the archive.
What would count. Any dataset with its methods and units, whatever its age or format. We'll publish it with attribution, or help you publish it yourself. Negative results and abandoned programs included — especially those.
Every gluten-free grain. The title says sorghum because that is what we hold. Millet, rice and corn have a published cultivar study each and no released tables behind it; buckwheat has no cultivar malting study we have found. The same offer stands for any of them (Open Problems).
Pages. Where this ask's card appears: Madison screening · 2002 to 2004 screenings · Hartwick 2019 · Midwest 2019 · LCBO certificates · Production QA log · Comparing grains · USDA 2023 protein NIR
Ask 9 — screen sorghum cultivars for brewing enzyme activity after standardized malting
The question. We design conversion around external enzymes because current sorghum malt doesn't supply reliable endogenous activity. How much of that is the grain? Across available cultivars, malted under one standardized protocol, how much do alpha-amylase, beta-amylase, and limit-dextrinase activity actually vary — and is any cultivar materially better than the current baseline?
Why it matters. The external-enzyme position is a workaround, and we say so. If cultivar variation is large, breeding and selection could change what gluten-free malt is capable of; if it's small, the answer lies in malting method instead, and that's worth knowing too. The alpha-amylase and diastatic-power spread is published — our own Madison screening carries 25 cultivars malted under one standardized schedule, with units. Beta-amylase and limit-dextrinase are the gap. Neither that dataset nor the 2002–2004 screenings reports them, and we have found nobody who has.
What would count. Several cultivars — including whatever the screenings already on file point to — malted under one published steep, germination, and kiln schedule, with enzyme activities measured by one named method and reported with units and replicates. Report the baseline cultivar alongside the rest. A result that shows no useful variation is as publishable as one that finds a winner.
Who could answer this. Elke Arendt (kilning and enzyme work), Bernardo Pontes Guimarães and Scott Lafontaine at the University of Arkansas (the rice cultivar-malting protocol and its cost model), and R.C. Agu (1995 sorghum varieties with external enzymes). Disharoon and colleagues (2021) already screened malt amylase activity across a sorghum diversity panel, so part of the spread is published; the standardized-malting comparison is not (Researchers; Sorghum).
Theory this would test. The fourth germination day buys alpha-amylase, not diastatic power, if the screening is run at two germination lengths.
Pages. Where this ask's card appears: Cultivars for malting · What makes good malting sorghum · Madison screening
Ask 10 — the calcium ladder: what does the mash actually need?
The question. Production ran ~100 ppm calcium as a complete-process baseline; the enzyme is documented to work below 20 ppm. Where between 20 and 100 does performance actually change — and in what?
Why it matters. The gap between the enzyme capability statement and the production condition is this site's standing open contradiction. A brewer targeting 100 ppm may be hauling chloride or sulfate along for a reason that no longer applies — or for one that matters and was never written down.
What would count. The same 100% sorghum malt recipe run as a calcium ladder — say 20 / 50 / 100 ppm, everything else held steady — reporting mash behavior, conversion (iodine), runoff, pH path, fermentation curve, and finished-beer impressions. Even two rungs move it. A bench running the GFB-SME reference mash across the ladder counts double.
Pages. Where this ask's card appears: Water, minerals, and pH
Ask 11 — can anything close sorghum's FAN gap, and at what cost?
The question. Sorghum malt FAN runs roughly half of barley malt's. How much of that gap can a protease rest, malting modification, or cultivar choice close — and what does each close cost in foam, body, or flavor?
Why it matters. Every sorghum fermentation inherits this gap; yeast nutrition is currently designed around it rather than through it, and kafirin is the mechanism underneath. Knowing which lever moves FAN — and what it breaks — turns a permanent workaround into a design choice.
What would count. One variable at a time against a control: a protease rest (time and temperature declared) versus none on the same malt; or one cultivar at two germination lengths; or two cultivars under one malting schedule. Report FAN in ppm with the method declared, the fermentation curve, and honest foam and body notes. Partial answers are answers.
Who could answer this. Cockburn, Elias and Hopfer at Penn State, holders of the one funded FAN award in the directory (Researchers).
Pages. Where this ask's card appears: Yeast nutrition · Fermentation management
Ask 12 — where is the rice-hull floor?
The question. On a given malt, crush, and system, how low can the rice-hull rate go before the bed fails — and does a deliberately coarse grind reach zero?
Why it matters. The published position is "start around 5%, then move down" — direction without a floor. Hulls are cost and bed volume; the floor is the number every production brewer actually wants, and the historical figures were never reconciled.
What would count. A split batch — one grist coarse-ground with no hulls, one at 5%, same malt and system — reporting runoff time, bed behavior, and whether either stuck. A descending series (5% / 2% / 0%) across brews on one system is the full answer. Include your crush description: the grind is half the experiment.
Pages. Where this ask's card appears: Rice hull strategy · Stuck mash survival
Ask 13 — koji-inoculated sorghum malt on an all-malt grist
The question. Sorghum malted with 1% Aspergillus oryzae has been carried through to finished gluten-free lager once, at bench scale, on a 60% malt / 40% maize grist with formaldehyde in the steep (Where Conversion Power Comes From). Does the result survive an all-malt gluten-free grist, a mould-control method a maltster could run, and a mash a brewer could run?
Why it matters. Koji is the one route that supplies free amino nitrogen along with sugar, and gluten-free wort runs short of it. If the bench result holds on a real grist, the external-enzymes position narrows the way its own record says it would; if it doesn't, the "promising" reading of the two Monterrey papers is closed.
What would count. Koji-inoculated sorghum malt made without formaldehyde, brewed as 100% gluten-free malt under the reference mash against the same malt uninoculated, reporting malting loss, extract, FAN, iodine result, runoff time, attenuation and a tasted beer, with replicates. Filtration on the all-malt grist is the number nobody has published.
Who could answer this. The Serna-Saldivar group at Tecnológico de Monterrey, who ran both studies; the Montana State University koji-malt programme, which has already run the full ASBC malt panel on barley koji (Researchers; Koji and Grown Enzymes).
Theory this would test. None entered yet; the position it tests is on the routes page.
Pages. Where this ask's card appears: Where conversion power comes from · External Enzymes · Koji research directory
Ask 14 — walk through the door the practitioner fund already opened
The question. Will the American Homebrewers Association's Research & Education Fund pay for a gluten-free brewing or malting project, and will a practitioner propose one?
Why it matters. This site spent a year recording that no funder reaches practitioner scale. That is half right. The award gap is real: we have found no grant to a homebrewer or home maltster for gluten-free work. The eligibility gap is not — the fund names any member as eligible, encourages proposals "of all backgrounds and expertise", and reimburses on an accepted write-up, with results published by the association. Nobody in this category appears to have asked. That is the cheapest correction available to a field that says it has no money: not a new funder, an application.
What would count. A submitted proposal, and what happened to it. Any of this site's homebrew-scale asks would serve — the mycotoxin panel from home-malted grain (Ask 3's neighbour, and the one with a medical edge), the rice-hull floor, or the enzyme dose curve. A rejection is worth publishing too: it would tell the field what the fund will not cover.
Pages. Where this ask's card appears: Homebrew and home malting · Homebrewers and home maltsters
Ask 15 — attenuation, measured on the wort we actually brew
The question. What apparent attenuation does a given strain reach on sorghum or millet wort, and how far is that from the number on its data sheet?
Why it matters. Every published attenuation range was determined in all-malt barley wort at roughly a 1:5:1 glucose-maltose-maltotriose ratio. Gluten-free wort is glucose-forward, and glucose ferments faster and more completely than maltose. A brewer choosing a strain on its published attenuation is planning against a number generated on a substrate they are not brewing. We have found no strain house publishing attenuation determined on gluten-free wort; suppliers address this category by confirming the yeast is gluten-free, which answers a different question.
What would count. One strain, two worts, same gravity and pitch rate: barley all-malt against a gluten-free wort, reporting apparent attenuation and the sugar spectrum of each. A supplier could answer it from existing records; a brewery could answer it in one split batch. Either publication closes it.
Pages. Where this ask's card appears: Yeast and fermentation · Yeast management and propagation
Ask 16 — fermentation temperature on this beer, not on sorghum in general
The question. On a 100% sorghum-malt wort and a lager strain, what does moving fermentation temperature do to attenuation, ester profile and finished flavour?
Why it matters. This site published a temperature schedule as one company's practice and, until 2026-09-09, said no controlled comparison existed. That was wrong: sorghum wort has been fermented across a range from ambient to 40 °C (104 °F) in one study, and at 12 °C (54 °F) against 25 °C (77 °F) in a 2025 one, both finding a significant effect on alcohol and yeast growth. What those studies do not cover is a lager strain on a gluten-free malt wort at brewery scale, which is the case our schedule speaks to. The literature gives this ask two starting points instead of a blank page.
What would count. A split fermentation at two setpoints on one wort and one strain, reporting attenuation curve, volatile panel and a tasted beer. The 2025 design is directly borrowable.
Pages. Where this ask's card appears: Fermentation management · Yeast and fermentation
Ask 17 — malt buckwheat cultivars and publish the table
The question. How do named buckwheat cultivars differ as malt, measured under one schedule?
Why it matters. Of the grains this site tracks, buckwheat is now the only one with no cultivar-by-malt-quality study we can find. Millet has 24 proso varieties under one regimen, rice has 19 cultivars malted and brewed, corn has a maize varieties study, sorghum has the screenings we republish. Buckwheat has a complete brewing corpus and no varietal layer under it — the one grain whose foundational questions were answered before anyone asked which variety to grow. It is also the grain the United States exports while domestic gluten-free malting buys what it can get.
What would count. Six or more named cultivars micro-malted under one schedule, reporting extract, diastatic power, free amino nitrogen and gelatinisation temperature — and the rows, not only the conclusions. Publishing the table is the part that makes it usable; none of the studies for the other grains released theirs, which is the gap this ask is really about.
Pages. Where this ask's card appears: Buckwheat · Open problems
Ask 18 — what diastatic power is actually enough to self-convert?
The question. For an all-malt sorghum mash with no exogenous enzymes, what diastatic power does the malt actually need? Not "more is better" — the number at which conversion becomes reliable, and what happens either side of it.
Why it matters. The proposed grain specification has to give breeders working toward native conversion something to aim at, and it cannot. Profile B proposes 30 and 40 diastatic power, and both are honestly labelled as percentiles of published screenings rather than evidence of sufficiency — 30 is roughly the upper half of everything measured, 40 approaches the single best result on record. Neither says a lot meeting it will convert. Every sorghum malting standard in the field leads with diastatic power, and we can find nobody who has published the figure that makes it a threshold rather than a ranking. Until that exists, a breeding program selecting for native conversion is aiming at a percentile.
What would count. Malt across a diastatic-power range — the Madison screening spans 19 to 46 and names the cultivars — mashed without added enzymes on one published schedule, with conversion measured rather than assumed. Report the method and units for the diastatic power figure, because they do not interconvert cleanly. A result showing that no sorghum malt in the published range self-converts reliably is as valuable as one that finds the line, and would settle the external-enzyme question with evidence instead of doctrine.
Who could answer this. A university malting and brewing bench with enzyme assay access. Melinda Yerka's UNR program evaluates malting and brewing quality across sorghum genotypes and production environments; the Madison dataset provides the cultivar range to draw from (Researchers; Sorghum).
Pages. Where this ask's card appears: Malting sorghum specification · Forget native malt enzymes · Madison screening
Ask 19 — reconcile the sorghum alpha-amylase methods
The question. Two of this site's own datasets report alpha-amylase on sorghum malt and differ by roughly five to ten times. Which methods produce which numbers, and what conversion — if any — holds between them?
Why it matters. Bard's production malt measured under 10 DU. The 25-cultivar Madison screening reports 48 to 120 DU. Both are real measurements of real sorghum malt, and they cannot both be describing the same scale. One column in the 2002–2004 screenings is recorded, honestly, as diastatic power in unlabeled units. SABS 235 exported this problem to the entire field — sorghum enzyme results exist in SDU, degrees Lintner, degrees Windisch-Kolbach and ASBC, and they do not interconvert cleanly. The practical cost is that no enzyme target can be written into a specification without naming its method, and a buyer comparing two certificates may be comparing nothing at all.
What would count. One malt sample, split, run by two laboratories under two named methods, with both results published alongside the full method descriptions. Several samples spanning the activity range would be better. A finding that no stable conversion exists is a publishable and useful result: it would mean the field has to standardise rather than convert.
Who could answer this. Any two laboratories willing to run a split sample and publish both numbers — a commercial malt lab and a university bench would do it. This is among the least expensive asks on this page and one of the most immediately useful.
Pages. Where this ask's card appears: Malting sorghum specification · Evaluation methods compared · SABS 235
Ask 20 — does late-season cold move sorghum grain protein?
The question. Does a late-season cold event during grain fill change sorghum grain protein, and by how much? More broadly: how much does the same cultivar in the same region move between crop years, and what drives it?
Why it matters. Barley's specification does not carry a stability requirement, and it does not need one: a century of selection for protein stability, official recommendation lists, and an elevator that discounts off-spec grain into feed mean the variance is filtered out before a maltster sees it. As Sorghum Protein and the Missing Specification puts it, that consistency is the output of a functioning quality system rather than a property of the plant. Gluten-free sorghum has no such system — no recommendation list, no malting premium, no rejection pathway — so stability has to be written into the specification instead of assumed. Part 3c of the grain specification proposes a protein spread of no more than about two percentage points across crop years, reasoned from US hybrid trials where hybrid choice alone moved location-averaged protein from 10.8% to 12.7%. What that proposal cannot account for is weather, and a cold snap during grain fill is the specific case we have no figure for.
What would count. Grain protein for one named cultivar, same region, across several crop years, with the season's weather recorded — particularly late-season temperature. Multiple cultivars would separate genotype from environment. Existing records would serve; this may be an archive question rather than a field trial.
Who could answer this. Seed companies with multi-year trial data, extension agronomists, and the UNR program evaluating production environments, which already studies nighttime temperature across elevations (Breeders & Agronomists; Growers).
Pages. Where this ask's card appears: Malting sorghum specification · Sorghum protein and the missing specification · Seed traits for malting
Status vocabulary
Open — nobody we know of is working on it. Seeking testers — we're specifically looking for people to run it. Seeking review — a proposal needs technical criticism more than data. Under evaluation — results are in hand and being worked through. Closed — answered, with the page updated to say so. Superseded — the question changed.
An ask leaving this list should leave a mark on a published page. That's the whole point.
Related
- Open Problems — the frontier these asks are drawn from
- Research Library — the data behind the questions
- Proposed Standards — proposals that need criticism
- Homebrew: The Research Bench — where several of these asks get run
- Contribute Research — what happens to what you send