Malting

with Peter Molenaar, Maltster, Malteurop NZ, Marton

Beer pretty much runs in the blood for Peter Molenaar, the master maltster for Monteith’s Single Source.

“My father and grandfather were employed by a Dutch brewery. From an early age I was helping out with cleaning and filling kegs and loading lorries over the weekends, when pubs in the area were running dry after a successful soccer game.

Peter has been making malt for 38 years, in 6 different maltings. Four in Europe, one in Australia, and now he's in Marton, New Zealand.

Maltsters make malt

Next to pure water, malted barley is the biggest ingredient in beer. It gives beer its taste, its body, and provides the materials that make the alcohol and the effervescence.

To malt barley, maltsters use the natural processes that turn a seed into a plant - and then they arrest these in time to harness the first energies of growth, . Of course, beer is a pretty laid-back affair, so brewers and maltsters don't go on about starting life and harnessing life-force and all that. (But that's what's happening).

The malting was built in Marton because it takes a great deal of energy to make malt and the Natural Gas pipeline, from New Plymouth to Wellington, just so happens to run straight past the site.

Peter's malting is a four-step process.

Step 1. Steeping

First, Peter takes Bill Davey's Charmay barley. It arrives dried-out to a humidity level of only 12%. Pure water is used to steep the barley - bringing the moisture level up to 42%. After around 40 hours of this, the water causes the grain to start to germinate and rootlets appear.

Step 2. Germination

The next step is to hurry along the germination process to produce enzymes and starches. These will then provide the material that other elements in beer, such as yeast, act with to make beer, well, beer.

Germination is aided by spreading the grains across a perforated floor, over which humidity and temperature-controlled air is continuously pumped through to allow the grain to breathe. The grain is watered and turned as needed until, after around five days of this, the germ is now the size of the grain and is what's called a green malt.

Step 3. Kilning

This is the stage that gives the malt, and so the beer, its colour and flavour. The green malt barley is heated in silos; a process that Peter controls meticulously.

As the malt heats, a whole bunch of natural processes around growth occur within the grain. As the heat increases, the rate of these do too, until a point is reached where the lowering humidity in the grain causes them to stop.

Charmay barley

At this point, the heat is, turned right up - to roast good flavour in, and roast everything that could spoil the grain out.

It is the length and method of the kilning that determines the colour and flavour of the malt, so a long exposure will create a darker beer. (In case you ever need this for a pub quiz answer, this is known as the Maillard Reaction). For Monteith's Single Source, the grain is lightly kilned, creating a particularly good lager.

Step 4. Deculming

The culm is the rootlet that was caused to pop out of the grain during germination. This is shaken off in this last stage with the aid of a vibrating screen, leaving the barley grain as malt - small, golden-yellow and Peter's proud contribution to this special brew.