Knowledge › The malting process

Barley can't be brewed straight from the field. Before it becomes beer, the grain must be malted — a controlled, partial germination that develops the enzymes and converts the grain so its starches can later be turned into fermentable sugar. Malting barley is, by definition, barley grown specifically to be malted and brewed; malted barley is the core ingredient of beer because it supplies the carbohydrates and sugars fermentation needs, and contributes much of a beer's flavour and colour.

The three core stages

At its heart, malting is three steps — steeping, germination and kilning — wrapped in cleaning at the start and finishing at the end:

Cleaning & grading

Incoming barley is screened and graded so only plump, uniform, viable grain enters the malthouse. Consistent grain size means consistent water uptake later.

Steeping

The grain is soaked in water — in alternating wet and dry cycles over roughly two days — until its moisture climbs to about 42–46%. This wakes the grain from dormancy and signals it to start germinating.

~1–2 days

Germination

The hydrated grain is spread out and allowed to sprout for several days under controlled temperature and airflow. Enzymes — especially alpha-amylase and others that build diastatic power — develop and begin breaking down the starchy endosperm. The result is moist, sprouted "green malt."

~4–6 days

Kilning (drying & curing)

Green malt is dried with progressively warmer air to halt germination, preserve the enzymes and drive colour and flavour development through the Maillard reaction. Higher kilning temperatures yield darker, more flavourful malts; gentle drying keeps pale malts light and enzyme-rich.

~1–2 days

Deculming & finishing

The brittle dried rootlets ("culms") are removed, and the finished malt is cleaned and stored, ready to ship to the brewery. Some malts are further roasted to create specialty styles.

Why each step matters for beer

Steeping and germination determine how well the grain "modifies" — how thoroughly its starch and proteins are made accessible — while kilning sets the malt's colour, aroma and how much enzyme power survives for the brewhouse. Get them right and the maltster delivers high extract, clean flavour and reliable performance; get them wrong and the brewer pays for it downstream. It all starts, though, with the right grain: low-protein, high-germination 2-row malting barley of a proven variety.

From malt to glass

Once malted, the grain heads to the brewery, where mashing, lautering, boiling, fermentation and conditioning turn it into beer. Follow the rest of the journey in our grain-to-glass brewing guide — including how non-alcoholic beer is made.

→ The brewing process (grain to glass) → 2-row vs 6-row barley → Malting barley varieties