Same barley, two very different malts: colour and aroma are decided in a few hours on the kiln. From gentle drying to the cure, from pils to munich.
Put two malt kernels side by side on the bench. The first is a pils malt: pale, almost white inside, crunchy, with a quiet taste of fresh grain and hazelnut. The second is a munich: amber, denser under the tooth, with clear notes of bread crust. Same malting barley, sometimes even the same field. The whole difference was decided in about thirty hours, on the kiln.
Kilning, the last act of malting
Fresh out of germination, malt is still "green". After four to five days of germination the kernel holds 42 to 45% water. Its enzymes are built and its starch reserves have been opened up — maltsters call this "modification" — but it cannot be stored, milled or brewed as it is. Leave it in a heap and it heats up, moulds, and tries to keep growing.
Kilning means drying while steering the flavour. The technical goal is simple: bring the grain from 45% down to 4 or 5% moisture so the malt becomes stable and friable. But how you get there — which temperature, at which moment, for how long — decides the malt's colour, its aromas and how much of its enzyme power survives. It is the step where the maltster stops nursing the grain and starts cooking it.
Gentle drying, then the cure
Every kilning starts low and airy. For the first hours, large volumes of air at 55–65 °C are blown through the grain bed. As long as the malt is wet, evaporation keeps it cool, much the way sweat cools skin. The enzymes, fragile in the heat, come through this phase almost untouched.
Then comes the curing phase — the maltster's "kick of fire". Once the grain drops below 10 to 12% moisture, evaporation no longer protects it: its temperature climbs to meet the air. This is the moment of truth. The kiln is pushed to 80–85 °C for a pils malt, around 90–95 °C for a pale ale malt, and up to 100–110 °C for a munich, held for two to four hours. A few degrees and a handful of hours separate malts that seem worlds apart in the glass.
Maillard, melanoidins and EBC
Malt colour is born from a kitchen reaction. The Maillard reaction — the same one that browns a bread crust or a roast — links the grain's simple sugars and amino acids into melanoidins, brown and deeply aromatic compounds. It races ahead when the grain is both hot and still slightly moist: that is why a munich is cured wetter and hotter than a pils, precisely to feed the reaction a pils maltster works to hold back.
Maltsters measure the result in EBC. A pils malt sits around 2.5 to 4.5 EBC, a pale ale malt at 5 to 7, a vienna at 6 to 9, a munich at 15 to 25. Since base malt makes up 80 to 100% of the grist, these small gaps set the colour of the beer: straw blond with a pils, golden with a pale ale, glowing amber as soon as a munich joins in.
Heat also has an enzymatic price. The hotter the cure, the lower the diastatic power — the malt's ability to turn starch into fermentable sugars in the mash tun. A pils malt keeps a comfortable enzyme reserve; a dark munich holds just enough to convert itself. That is the standing trade-off of kilning: aroma bought with enzymes.
Four malts, four registers
Pils malt is restraint. Dried gently, cured briefly and mildly, it keeps a maximum of enzymes and delicate notes of grain and light honey. It is the base of pils, of course, but also of witbiers, saisons and tripels — when the yeast should do the talking, pils malt hands it the stage.
Pale ale malt turns the heat up one notch. A little more colour, notes of biscuit and fresh bread, and still plenty of enzymes to carry a grist heavy with wheat or oats. It is the backbone of pale ales and lighter ambers.
Vienna and munich lean into the cooking. Vienna brings a quiet toasted roundness, munich frank aromas of bread crust and light caramel. An amber, a bock, a Belgian table brown owe them most of their character. And not only in the brewhouse: a few percent of milled munich in a dough gives bread a darker crumb and a more fragrant crust.
Let's be honest: no base malt replaces a roasted malt. For the chocolate and coffee notes of a stout you need malts roasted above 200 °C in a dedicated drum — a different trade, different equipment. A malthouse that makes base malts, from pils to munich, does not pretend to do everything; composing the recipe is the brewer's craft.
Kilning without burning gas
Traditionally, the kiln burns oil or gas. Driving forty points of moisture out of several tonnes of grain is by far the most energy-hungry step in a malthouse. In Dinant, the malthouse chose another path: kilning heat comes from biomass, delivered as hot water, topped up with renewable electricity — malting without fossil fuels. The single 5-tonne drum runs germination and kilning in the same vessel, at a rhythm of about one batch a week, from the first malting campaign starting in mid-October 2026, with Belgian organic malting barley — part of it grown on the founder's own Demeter-certified farm.
If the curing phase intrigues you, or if you are weighing vienna against munich for your next amber, the door is not far: come and see the kiln in Dinant, or write to the malthouse team via mad.be. Talking malt is still what we do best.