A visit to Gladfield Malt

A visit to Gladfield Malt

Gladfield Malts is New Zealand’s boutique maltster producing a number of base and specialty malts from their farm and maltings in Dunsandel, Canterbury. 

Starting with base malts for the local market, they are now producing a full range of specialty malts and are shipping these all over the world. 

Gladfield Malt is owned and operated by Doug and Gabi Michaels. Barley had long been grown on their Dunsandel farm and processed off site but that changed in 2003 when they built their maltings. Since then, the malt operation has driven the livestock from the farm and, to meet production demands, they now have other local farmers contract growing barley for them.

Gladfield’s prides itself on producing a high quality malt and ensures that all malt leaving their facilities is as fresh as possible. In addition to this, the malt is cleaned and small kernels removed so that when it arrives at the brewers, it is in the best possible condition to make the best possible beer.

Currently, Gladfield’s provides malt to around 90% of the micro-breweries in New Zealand and has growing exports to Australia and China with plans to conquer the emerging South East Asian markets. Their dedication to fresh product is important here, so that when it arrives in its foreign destination, the malt is still well within its use-by date.

Since building their initial maltings, they have added a roasting machine, and smoker to their equipment which has them producing a full range of specialty malts as well as their new Manuka smoked malt.

As well as this, they have built a complete quality control laboratory which they also use to develop new malt colors and flavors. Their Shepherds Delight malt was a collaboration between themselves and Australian microbrewery Mountain Goat Beer, the aim being to develop a malt which would impart a deep red color to the beer.

 We got to peek inside their maltings and see how barley malt is made...

Making Malt.

 1.    Steeping.

Making base malt is a three-stage process which requires careful attention along the way.

Steeping the barley in water is the first step in the process. The grain, which has been dried at harvest, is packed into a large vessel known as a steep by auger.

In the steep, the barley is  soaked or sprayed with warm water several times until it reaches 43-44% water content which starts the germination process.

 2.    Germination.

After steeping, the barley is transferred to another vessel known as a GKV, or a Germination-Kiln-Vessel. The steeping has set the grain growing just as if it had been sown in a field.  Like any growing organism, it requires oxygen so air is blown into the bottom of the GKB to support this.

As the embryonic root emerges from the husk of the seed, it is allowed to grow for up to five days or until it reaches the desired length and is stirred constantly by a mechanical auger. During this time, the seed is producing the enzymes it needs to develop into a plant. These enzymes include the amylases, which are so important to brewers.

Often you will see reference to a ‘well modified’ barley malt in a recipe or brewing text-book. This refers to the modification of the barley grains occurring at this stage.

Traditionally, the grain was spread thinly over the floor and turned by paddles in a practice known as floor malting. Although some malsters still produce floor malted barley, this practice has largely been replaced by ‘pneumatic plants’ which blow air and turn the grains through mechanical means.

Barley germinating in the GKV

3.    Kilning.

The final step in producing base malt is drying the grain in the kiln. When the embryonic root is at the desired length, heated air is blown through the grain bed. Drying the grain kills the embryonic plant, which freezes the germination process and the enzymes, holding this in place.

Pale malts are kilned to 95-105°C, while mild malts are kilned at slightly higher temperatures. Vienna and Munich malts are kilned at around 110 and 115°C respectively, and it is these higher temperatures which create the melanoidins found in these varieties.

Great care is taken to heat the malt gradually and evenly throughout the batch. At temperatures above 110°C, the degradation of the enzymes becomes significant.

Malted Barley in the GKV


Roasting and specialty malts.

Base malts with their intact enzymes reside at the straw colored end of the spectrum but specialty malts come in all shades of brown to jet black. To get these varieties requires different temperatures and durations of roasting. 

Crystal or caramel malts are distinct in that after malting, they are stewed in water at around 68°C before roasting; this is essentially a mash inside the grain where the starch is broken down into smaller chain sugars. When the grain enters the roaster, these sugars are caramelised which produces the distinctive shiny sugar crystals inside the grain when it is crushed open.

The roasting machine is essentially the same as you would use for roasting coffee and the unit at Gladfield’s was commissioned for them in the Czech Republic. The processes producing the colour and the different flavours is known as Maillard browning and is the same process which turns pastry brown.

When temperatures exceed 140°C, this is hot enough for carbohydrates and proteins to start breaking down. In the Mailard browning reaction, the carboxyl (acid region) of an amino acid will react with a carbohydrate; the number of combinations possible is nearly limitless.

This is the reason why more darker roasts such as chocolate malts or roasted barley share some similar flavours with coffee beans. Unmalted barley is used for these varieties though and temperatures can be as high as 1000°C (2000°F).

During these high temperature roasts, water is sprayed to cool the husk of the grain which stops it from charring and reduces the acridity of the resulting roast.

The progress of the grain in the roaster is closely monitored with samples taken regularly. When the desired level of roast has been achieved, the grain is dumped into a cooler, which stirs it while blowing cool air through the grain to cool it and prevent further roasting.

Chocolate malt is dumped in to the cooler after roasting.

Chocolate malt in the cooler after being roasted.

Why we do while we brew.

With so much dedication to ensuring a top quality product, it is little wonder that the Gladfield Malt company has grown so rapidly. Here at Brewshop, we order monthly by the tonne which is testimony to its popularity.