Water, Minerals, and pH

Target about 100 ppm calcium as the working baseline for The Reliable Mash — a process baseline, not an enzyme minimum; the liquefaction enzyme itself needs none. In a gluten-free mash the water is not a backdrop: it sets the pH and the mineral conditions your external enzymes need to work. Get it wrong and a good grist still gives you a bad conversion.

The control table

What to control	Target or starting point	How drift shows	What to do
Mash pH, the Reliable Mash	5.5 to 5.6, measured temperature-corrected at the actual step	A cold sample read hours later; a value assumed from a salt recipe	Measure at the step, adjust with acid, record the addition
Mash pH, the Maltose Mash	6.0 at the 122°F (50°C) protein rest, 5.5 at the 132°F (56°C) conversion	The fungal alpha dosed off its pH	Adjust down before the fungal alpha goes in
Calcium	About 100 ppm as the complete-process baseline; production ran 100 to 150 ppm; Termamyl SC DS itself needs none		Adjust with calcium chloride and record; treat the figure as a tested condition, not an enzyme minimum
Chloride and sulfate	Restrained where practical	A calcium addition that quietly moved the chloride-to-sulfate balance	Track every salt addition; gypsum brings sulfate, calcium chloride brings chloride
Source water	A profile in hand: calcium, alkalinity, chloride, sulfate	Additions calculated from nothing	Get the profile first, then calculate

Barley brewers can lean on generations of water-chemistry lore built around barley malt. Gluten-free brewing does not inherit that. When conversion depends on a designed external-enzyme program working on gelatinized sorghum starch, the mash environment — pH, calcium, and the ions that come along with your salt additions — stops being a detail and becomes part of the process.

None of this is doctrine. The only doctrine is no wheat, barley, rye, or oats. Everything on this page is a working baseline from commercial practice to validate on your own water, malt, and equipment.

Start with your source water

You can't target a mash pH or a calcium level without knowing what you already have. Get a profile of your source water — at minimum calcium, alkalinity, chloride, and sulfate — and calculate additions from there. Treating tap water as a blank slate is how you end up chasing a mash that will not convert.

Mash ph

Mash pH is the single most important water lever, because enzyme activity is pH-dependent. The GFB working target is mash pH 5.5 to 5.6, measured and recorded at the actual process steps — not assumed from a salt recipe.

• Measure at the real conditions (temperature-corrected), not a cold sample hours later.
• Record pH by step. A batch record that shows the pH the mash actually experienced is what lets you connect a disappointing conversion back to a cause.
• Adjust with acid as needed to reach the target; note the addition.

A number without context is dangerous: 5.5–5.6 is where the GFB enzyme program was run, not a universal constant. Your enzyme products, grist, and water may move it.

The Maltose Mash runs two pH targets, and one of them is not 5.5

The working target above is the Reliable Mash's. The Maltose Mash runs pH 6.0 at the 122°F (50°C) protein rest and pH 5.5 at the 132°F (56°C) conversion. The conversion figure is not a preference: fungal alpha-amylase is pH-sensitive, and dosing it at the wrong pH wastes the run. Set and confirm pH before the enzyme goes in, and record it.

Calcium

The GFB complete-process working baseline is approximately 100 ppm calcium — the working notes from the production program put the range at 100–150 ppm. Calculate the addition from your source-water profile and record calcium, chloride, sulfate, acid, and salt additions.

For a year this page carried an open question behind that number. It's answered now, and the answer is worth stating plainly because it changes what the number means:

Novozymes' brewing documentation states that Termamyl SC DS has no calcium dependency — it works below 20 ppm. The same documentation says Termamyl Classic needs 50–150 ppm. In November 2019 the enzyme distributor's guidance set the water at 100–150 ppm calcium for a protocol that was, at that moment, running Classic; two days later the protocol switched to SC DS and the calcium note was never revisited. Production kept the range for every batch after that and never had a calcium-related failure. So the ~100 ppm is production practice that carried over from a different enzyme — a tested condition, not a requirement of the enzyme you will actually use. Target it because the protocol ran on it; do not read it as a Termamyl minimum, and if you want to know what the whole process actually needs, that is Ask 10.

This is exactly the kind of number to validate, not worship. Both mashes run CaCl₂ to approximately the same –100 ppm, so this baseline carries across — see The Reliable Mash and The Maltose Mash for the full protocol context in each.

Why we take this positionexpand to view

Position. Target approximately 100 ppm calcium as the complete-process working baseline for The Reliable Mash. Don't read it as an enzyme minimum. Calculate from your source water, record every addition, and validate the number on your own system.

Basis. Commercial production experience — Bard's ran this range — with the 100–150 ppm figure traced to 2019 enzyme-distributor guidance for the enzyme system in use. Working baseline, not a manufacturer requirement.

Why. The external-enzyme program only works inside the pH and mineral conditions it needs, and calcium is part of those conditions. The production record used about 100 ppm for the whole process and the process was reliable. Until the reason for the gap between that figure and the enzyme's own stated tolerance is recovered, the conservative number is the one we publish.

The problem forcing it. The original reason for the higher complete-process calcium condition was never written down and has not been recovered. That leaves a published number without a published rationale.

Compensation or ideal? A compensation. A conservative baseline is standing in for a known requirement. The ideal is a recovered rationale, or a measured floor across the whole process, so the number can be set to what the process needs and the chloride and sulfate that come with it can be chosen on purpose.

Evidence.

• Bard's production records at about 100 ppm complete-process calcium — commercial experience, the primary basis.
• 2019 enzyme-distributor guidance for the enzyme system, stating the level helps the enzymes work efficiently and advising restrained chloride and sulfate — supplier guidance, the located historical source of the range.
• The enzyme maker's documentation stating the liquefaction enzyme operates below 20 ppm calcium — an enzyme-capability statement, not a process target.
• Held since September 2026: the reason production used the higher figure — the range was advice for Termamyl Classic, which the protocol ran for two days before switching to SC DS with the note unchanged; confirmed by Craig.

Open contradictions. None since September 2026. What read as a contradiction — an enzyme that needs no calcium and a process that targets 100 ppm — was a history: the target was set for a different enzyme and carried over. Both facts are still stated here; the enzyme's tolerance and the production condition simply belong to different questions. What remains open is not a contradiction but a measurement — whether the complete process needs the calcium — which is Ask 10.

What would change our position. A controlled calcium ladder on the complete process — same malt, same enzymes, same system — judged on conversion, runoff, fermentation, and finished beer. Either would replace a conservative number with a known one.

Related research asks. Ask 10 — the calcium ladder: the experiment that would resolve this position's open contradiction.

Commercial interests. None. We hold no financial interest in any enzyme or brewing-salt supplier.

Consequence if wrong. Process. Salts and the ions that ride with them, added for a reason that may not apply — or a conversion that suffers on a system that needed more.

Decision owner and status. Craig Belser · Current · baseline governed July 2026 · last reviewed August 2026.

History. September 2026: the open question closed. The archive, read first-hand, shows the 100–150 ppm advice was given for Termamyl Classic, which the protocol ran for two days in November 2019 before switching to SC DS with the calcium note unchanged; Craig confirmed the figure carried over and was kept as production practice (SP-0006, DR-0068-era review). July 2026: one earlier record combined the working baseline, its source, and the open question; it was split into three, and the source of the 100–150 ppm range was corrected from an earlier misattribution to a different supplier to the 2019 enzyme-distributor guidance. The number did not change.

Chloride and sulfate

Keep chloride and sulfate restrained where practical. This is Bard's process-specific guidance, not a universal water target — beer style still matters, and different designs want different balances.

The practical trap is that the salts you add for calcium bring these ions with them: gypsum adds sulfate, calcium chloride adds chloride. So a calcium addition is also a chloride/sulfate decision. Track every addition, because high levels can interfere with enzyme performance, and you want to be able to tell a flavor or process result from the mineral change that caused it.

Record it, then validate it

Control	GFB working baseline	What to record
Mash pH	5.5 – 5.6	Measured pH by step, acid additions
Calcium	~100 ppm (complete-process)	Source Ca, calculated + actual additions
Chloride / sulfate	Restrained where practical	Every salt addition and the resulting profile
Source water	Known before adjusting	Full starting profile

Run these as a starting point, measure what the mash actually experienced, and let the finished beer and your conversion checks tell you whether to move them. Water is a process variable to control and prove — not a fixed recipe to copy.

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Related: External Enzymes · Gelatinization · The Reliable Mash · Batch Records