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The Problems We Still Need to Solve in Gluten-Free Brewing

This is the frontier. Most of what we publish as guidance is a way of working around something the field has not solved — a malt that cannot convert on its own, a grain with no specification, a hold sized to cover variation nobody has measured. Here is that list, in the open, with what we know, what we don't, and the work that would move each one.

A knowledge base tells you what is known. This page tells you what isn't. Every problem below is drawn from a position this site already takes — the "why we take this position" record on the owning page names the problem that forces it — or from an open Research Ask. Where the honest answer is "nobody has measured it," that is what it says. An empty line is a fact about the record, not an invitation to invent.

Problems are ordered within each category by how much a solution would change published guidance, and we say why at the top of each group. The order is ours; the evidence is on the linked pages.

Raw materials​

Raw materials2 problems

Ordered by how much a solution would change what a brewer can buy. Supply is the constraint everything else sits behind.

Malting-sorghum seed and malt do not exist at qualifying scale​

The problem. There is no identity-preserved malting-sorghum seed supply and no malted-sorghum supply in North America that meets a published truly-gluten-free standard at commercial scale. Why it matters. Every brewer who wants to run a 100% sorghum malt process must either malt their own or source from a single-digit number of producers, none of whom can guarantee cultivar identity lot to lot. Where we are. We track identity lot by lot instead — see Cultivars for Malting — and keep a standing invitation to anyone who will make the malt. What we know / don't know. Known: which named cultivars malted well in the USDA Madison screening, at one location. Not known: whether any of them perform across locations and crop years; whether seed rights for the best lines can be secured. Open contradictions. None. Research asks. Ask 8; Ask 9. Status. Open — blocked on supply.

Sorghum malt data from other producers is not public​

The problem. Sorghum malting has been done commercially and experimentally for decades, and almost none of the resulting malt analyses, screening data, or brewing trials are published. The record this site holds is one program's. Why it matters. Every new maltster and brewer starts from near zero, and every failure is repeated. Where we are. We publish everything we hold with DOIs and ask for the rest. What we know / don't know. Known: our own datasets, the published academic screenings, and the South African methods literature. Not known: what sits in the filing cabinets of programs that ended. Open contradictions. None. Research asks. Ask 8. Status. Open — standing.

Malting​

Malting1 problem

One problem, and it is the one most of our process guidance is built around.

Sorghum malt does not supply reliable endogenous conversion enzymes​

The problem. Gluten-free brewing malt carries measurable enzyme activity, but not reliably enough, lot to lot, to plan a commercial mash around. Sorghum malt's beta-amylase and total diastatic power run markedly below barley malt's. Why it matters. It forces every brewer onto external enzymes, which cost money, add process steps, and make the malt's own conversion potential irrelevant to how it is designed. Where we are. Malt for character; external enzymes own conversion. That position says plainly that it is a compensation for the malt, not the ideal. What we know / don't know. Known: the spread of diastatic power and alpha-amylase across 25 named cultivars at one location (Madison screening); that some cultivars are markedly better than others. Not known: how much of the variation is genetic versus malting method; whether any cultivar under a standardized malting protocol reaches a level a process could rely on. Open contradictions. None. Research asks. Ask 9; Ask 6. Status. Open — workaround holding.

Mashing and conversion​

Mashing and conversion4 problems

Ordered by how directly a result would change a number in Mash Protocol 1.

The 190°F / 60-minute hold may be hotter and longer than conversion needs​

The problem. The baseline hold is sized to cover malt-lot, equipment, and scale variation that nobody has measured. A 30-minute hold worked in most production runs. The floor is unknown. Why it matters. Energy, time, and — at production scale — throughput. A brewer who could validate a lighter hold on their own system saves all three on every batch. Where we are. 190°F for 60 minutes, validate anything lighter across several batches and lots. What we know / don't know. Known: the baseline transferred to two outside breweries and was highly reliable in commercial experience. Not known: where temperature or time actually stops working, on any malt. Open contradictions. None. Research asks. Ask 7; Ask 3. Status. Open — workaround holding.

The external-enzyme dose floor is unknown​

The problem. Published doses are conservative production insurance. Nobody has published the curve showing where conversion, runoff, or fermentation breaks as dose comes down. Why it matters. Enzymes are a real line item. If half the dose works, that is money back for every gluten-free brewer. Where we are. The documented protocol doses, stated as a starting point. What we know / don't know. Known: the doses that worked in production. Not known: the minimum. Open contradictions. None. Research asks. Ask 6. Status. Open.

MP3, the maltose mash, was never tested against MP1 — and the reason MP1 won was never recorded​

The problem. A protease rest plus a fungal-alpha coolback was written up and played with at Bard's; the glucoamylase finish won in production, and nobody wrote down why. Everything downstream of wort sugar profile — fermentation behavior, body, drinkability — rides on this. Why it matters. If MP3 makes a materially better beer from sorghum malt, the production recommendation is wrong. If it doesn't, the field should know why. Where we are. Mash Protocol 3 is published as proposed, untested, and a revival. What we know / don't know. Known: the proposed method and the reasoning. Not known: the side-by-side result. Open contradictions. None — this is an untested alternative, not conflicting evidence. Research asks. Ask 4 — the first problem this site is working by hand, with outside testers. Status. Under investigation.

The calcium baseline's original reason was never recovered​

The problem. Production ran a complete-process calcium condition of about 100 ppm, with period enzyme-distributor guidance behind it. The enzyme itself is documented to work below 20 ppm. Why production used the higher figure is not in the record. Why it matters. A brewer targeting 100 ppm may be adding salts — and the chloride or sulfate that comes with them — for a reason that no longer applies, or for a reason that matters and is unstated. Where we are. Target about 100 ppm as the complete-process baseline; do not read it as an enzyme minimum. What we know / don't know. Known: what production ran and what the enzyme maker states. Not known: the reason for the gap. Open contradictions. One, unresolved: the enzyme capability statement and the production condition point in different directions. Both are published on the owning page; neither is averaged. Research asks. None yet. Status. Open — evidence request standing.

Protein and fermentation​

Protein and fermentation1 problem

One recorded problem. This category is thinner than the field deserves.

Sorghum malt FAN runs about half of barley malt's​

The problem. Free amino nitrogen across the sorghum malts we screened ran roughly half the level a barley-malt wort gives the yeast. Fermentation support that barley brewers get for free has to be designed in. Why it matters. Sluggish or incomplete fermentation, off-flavors, and yeast health all trace back here. Where we are. Treat yeast nutrition as a process goal, not an afterthought. What we know / don't know. Known: the FAN spread across 25 cultivars and the published literature agreeing on the pattern. Not known: how much protease, malting modification, or cultivar choice can close the gap, and at what cost to foam and body. Open contradictions. None. Research asks. None yet. Status. Open.

Process​

Process1 problem

The rice-hull figures actually run in production were never reconciled​

The problem. Production ran about 4.8% rice hulls and lautered clean; mature sorghum operations run under 2%, some none. The figures actually run at one outside brewery — 2% versus 5% — and whether a true 0% trial ever occurred, are not firmly reconciled in the record. Why it matters. Hulls are cost and bed volume. A brewer who can go lower with a coarse grind should; one who can't needs to know where the floor is. Where we are. Start around 5% when bed behavior is uncertain; experience moves the number down. What we know / don't know. Known: the direction. Not known: the floor on a given malt and system. Open contradictions. None. Research asks. None yet — a homebrew-scale split batch would answer most of it. Status. Open — evidence request standing.

Sensory​

Sensory1 problem

Hop performance against sorghum malt is unmapped​

The problem. Hop variety guidance is barley guidance. Which varieties and rates work with sorghum malt's character, and which fight it, has never been systematically compared. Why it matters. Flavor is what sells the beer, and the usual rules of thumb were written for a different grain. Where we are. Hops and yeast for sorghum malt gives the working guidance; the 5-IBU hop-extract rule covers foam. What we know / don't know. Known: what worked in production. Not known: the comparison. Open contradictions. None. Research asks. Ask 1; Ask 2. Status. Open — seeking testers.

Quality, safety, and testing​

Quality, safety, and testing2 problems

Ordered safety first. Nothing in this group may be worked around below the standard: no wheat, no barley, no rye, no oats, ever.

Verifying a gluten-free claim in a shared facility​

The problem. A brewery that also handles gluten grain can produce a beer with no gluten grain in it — and still cannot easily prove, batch by batch, that cross-contact did not occur. The evidence chain that would prove it is expensive and not standardized. Why it matters. The claim is a safety claim to a celiac reader. Getting it wrong harms people. Where we are. Work the question in order and prevent cross-contact upstream. Dedicated equipment is the control; testing is the check. What we know / don't know. Known: what dedicated production proved, batch by batch, over four years (Production QA Log). Not known: a validated, affordable evidence chain for a shared facility. We do not publish a workaround here. Open contradictions. None. Research asks. None yet. Status. Open — no workaround published.

No shared method for evaluating sorghum malt​

The problem. Commercial labs run the barley panel or the feed panel on sorghum malt, because that is what they have. Neither measures quite the thing. Suppliers and brewers cannot compare lots. Why it matters. Without a common method, a malt specification cannot exist, and without a specification, every lot is a test. Where we are. A proposed Sorghum Malt Evaluation Standard, draft, open for criticism, and a lot-reporting standard for what a lot must declare. What we know / don't know. Known: what each existing method measures and misses (Evaluation Methods). Not known: whether the proposed standard holds up when someone other than us runs it. Open contradictions. None. Research asks. Ask 5. Status. Open — seeking review.

Industry and supply chain​

Industry and supply chain1 problem

The market for malting sorghum has to be created before it can be supplied​

The problem. Growers will not plant malting sorghum without a buyer; maltsters will not malt it without a grower and a brewer; brewers will not commit without malt. Nobody moves first. Why it matters. Every technical problem on this page is easier with a supply chain and impossible without one. Where we are. We are trying to break the deadlock ourselves, and we say on that page and on the cultivars page what commercial interest we would hold if it works. What we know / don't know. Known: what the agronomy and the market data say (Sorghum Agronomy and Supply). Not known: whether demand at the scale a maltster needs exists yet. Open contradictions. None. Research asks. None — this is a coordination problem, not a research problem. Status. Open — blocked on coordination.

How this page changes​

A problem is added when a published position names one that isn't here. A problem moves when a research ask opens or closes, when a contradiction is raised or resolved, or when someone outside this site sends evidence that changes a position. Each change is dated below. When a problem is solved, it stays on the page, marked resolved, with the date — the record of what got fixed is part of the map.

Changes.

  • 2026-08-22 — Page created with 13 problems across eight categories, drawn from the first three published position records (external enzymes, the 190°F baseline, cultivar identity) and Research Asks 1–9.