What Malt Is
Malt is grain that has been steeped, germinated, and kilned. That three-step transformation is what converts a raw grain into a brewing ingredient capable of doing actual work in the mash.
Raw grain contains starch but not the active enzymes needed to convert that starch into fermentable sugar (the sugar wort yeast will eat). Malting builds those enzymes. Without malting, the grain cannot do its job in the brewery.
The Three Stages
Steeping — The grain is soaked in water to raise its moisture content from around 12–14% to approximately 42–45%. This triggers germination. Steeping time and temperature are controlled variables. For sorghum, optimal steeping is around 20 hours, though this varies by variety and target enzyme development.
Germination — The steeped grain is spread in a germination bed and held at controlled temperature and humidity for several days while the grain sprouts. Enzymes — primarily alpha-amylase (breaks starch chains internally) and beta-amylase (breaks starch chains from the ends) — develop during this phase. For sorghum, germination at 25–30°C for 4–6 days is the established range. Enzyme activity increases up to a peak, then begins to decline if germination runs too long.
Kilning — Germination is stopped by drying the green malt (freshly germinated, still-moist grain) in a kiln. Temperature and duration determine how much enzyme activity is preserved and what flavor compounds develop. Lower kilning temperatures preserve more enzymatic activity. Higher temperatures produce color and flavor at the cost of enzymes.
What Makes Malt Different From Raw Grain
After malting, the grain has:
- Active amylase enzymes capable of converting starch to fermentable sugar during mashing
- Modified proteins that are more soluble and available as yeast nutrition
- A friable endosperm (softer, more open grain interior) that mills efficiently
- Defined diastatic power (DP) — a measurable indicator of total enzymatic capacity
Raw grain has none of this. Running raw grain through a mash without the enzymes malting provides produces starchy, unconverted wort — not fermentable beer.
Why This Matters for Gluten-Free Brewing
Gluten-free grains like sorghum do not behave exactly like barley during malting or in the mash. The enzyme profile is different — alpha-amylase dominates in sorghum where beta-amylase dominates in barley. The starch gelatinization temperature is higher, requiring adjusted mashing procedures. The sugar profile produced in the wort varies by cultivar in ways barley does not.
Bard's developed its gluten-free beer using properly malted sorghum — not raw sorghum with commercial enzyme additions. That distinction mattered for beer quality and for proving the category could be taken seriously.
Source Notes
- Strongly supported: Three-stage process; enzyme development during germination; sorghum germination parameters (25–30°C, 4–6 days); Bard's use of malted sorghum
- Partially supported: Exact steeping duration (20h cited in research but varies by variety)
- Needs review: Specific kilning temperature ranges for sorghum (50–55°C noted in archive research)