By Jean Balchin 09/05/2017

Welcome to the History of New Zealand Science in 25 Objects! From ingenious pā fortifications and Tā moko uhi (chisels) to disposable syringes and the Britten motorcycle, New Zealand’s scientific innovations are fascinating, varied and internationally appreciated. Explore the history of NZ science and technology with Jean Balchin as she examines 25 objects we Kiwis have made – starting with a cold beer. 


Thus spoke the German theologian Martin Luther, in a sentiment echoed by Kiwis across the country. New Zealand has a fond relationship with this fine alcoholic beverage, from Captain Cook’s beery experiments with rimu bark and tree needles to Morton Coutt’s ground-breaking discovery of the continuous fermentation brewing process.

From a young age, Morton William Coutts exhibited a fervent interest in inventing. At the age of 12, he built himself a fully functioning x-ray machine. The following year, Coutts built himself a two-way radio station and became the first Kiwi to broadcast a shortwave radio signal and the first person ever to send a radio signal across the equator. After his father became seriously ill with the Spanish flu, Coutts took over the family brewery in Palmerston North at the tender age of fifteen.

Naturally, he applied this inventiveness and technical flair to the running of the brewery, and in the 1930s, began investigating the nature of yeast – the most important ingredient in any brewing. Coutts speculated that yeast could be “properly controlled” if he considered it “as a human being with a brain.” Noting the profusion of enzyme mechanisms operating for survival, Coutts said “instead of looking on the final product I always took notice of the yeast as an organism that produced whatever you ended up with.”

The Problem

To understand Coutts’s continuous fermentation process, it is first necessary to understand how beer is usually brewed. First, barley is soaked in water, which is then drained, allowing the barley to germinate. At the first sign of roots, the germinating is halted by heating. These sprouted barley seeds (referred to as ‘malt’) are crushed without destroying the husks, mixed in hot water and left to settle for some time. Into this liquid seeps the desired goodness from the malt. This liquid, or ‘wort’ is separated from the ground mash and hops are added to it for flavour. The wort is boiled, cooled and has yeast added, which begins to grow and reproduce ferociously. This hungry yeast consumes the sugars in the wort, converting them into alcohol and carbon dioxide, in a process that usually takes at least a few days. The carbon dioxide is released into the air and the alcohol stays in the beer. The beer is aged for between three weeks and three months before being bottled.

The Solution

Coutts separated the fermentation process into stages. In the first stage, the yeast grew and in the second stage, the fermentation began. The yeast was thus encouraged to either grow or produce alcohol. By splitting these two functions, Coutts created a continuous flow of sorts, enabling brewers to continually add raw materials to the first stage. They then could draw off a steady supply of finished beer from the second thus allowing the brewery to run constantly. This process was far more time efficient than the batch fermentation process of beer, shortening the brewing process by as much as several weeks.

Lion and Dominion breweries realised the brilliance of this method, and worked together to develop a practical way to use the method in a commercial brewery. In 1957, they opened the world’s first continuous fermentation brewery in Palmerston North, and the rest is history. Coutts’s ingenious approach to brewing revolutionised the brewing process worldwide, and propelled New Zealand far ahead in the international brewing spheres. So, the next time you sit down to enjoy a cold one, raise your glass to Morton Coutts.