Story: Agricultural processing industries
Page 5 – Grain processing
Importance of grain milling in colonial New Zealand
Flour milling was the most widespread industry in early colonial New Zealand and remained one of the largest industries through the 19th century. Flour milling turned wheat into flour, which was mainly used for making bread.
Wheat was grown in many parts of the country in the mid-19th century, but by the 1870s it was concentrated in the areas most suited to it – South Canterbury, North Otago and eastern Southland, where milling was an important industry.
The first mills in New Zealand were small hand-operated machines that turned wheat into flour. Wheat was an unknown foodstuff to Māori until northern chief Ruatara, who had sowed and harvested the first crop of wheat in New Zealand in 1813, obtained a hand-operated flour mill in 1814 from Samuel Marsden’s exploratory party. He is said to have ground some wheat and made a cake – in a frying pan.
Historic mill survives
New Zealand’s only surviving water-powered flour mill, Clarks Mill, also known as the Maheno Valley Roller Mills, is owned by Heritage New Zealand (formerly the New Zealand Historic Places Trust). The mill, near Ōamaru, and its specially constructed millrace from which it could draw water from the Kakanui River to power it, was built around 1865. At first it ground wheat and oats using grindstones powered by a water wheel. In the 1880s was converted to roller machinery powered by water turbines.
First flour mills
The first flour mill in New Zealand was built at the Church Missionary Society’s farm at Waimate North, beginning operation in 1834. It was made of timber, and powered by a water wheel set in a small stream.
Auckland’s first flour mills were built in 1844. The first, Mason’s Mill, was a windmill designed by William Mason, New Zealand’s first architect. It was built out of scoria rock at Epsom. The second was a water-powered mill at Mechanics Bay. By 1845 there were also three mills in Wellington, one in Nelson and one in Akaroa.
From the mid-1840s tribal groups in Waikato, Wellington, Taranaki and Whanganui invested in water-powered mills, usually to process the wheat they grew. Between 1846 and 1860, 37 flour mills were built for Māori owners in the Auckland province alone.
Whanganui River mills
The first mill on the Whanganui River was built on the Awarua Stream at Pūtiki in 1845. It was built by Tom Higgie under the direction of missionary Reverend Richard Taylor, who acted as a go-between for Māori and millwrights.
The most famous mill on the river was built at Matahiwi in 1854. Mill stones from Australia and cast-iron machinery and brass bearings from Britain were carried up the river by canoe. It was named Kawana Kerei in honour of Governor George Grey, who had donated the millstones as a personal gift to the Ngā Poutama people. Grey gave loans to Māori in other areas to build mills.
Before use, mill stones had to be ‘dressed’. This meant using a little pick to make sure the grooves in the stone stayed clean – or the bran would not flake off cleanly and darker flour would emerge. Richard Davis, who ran the Waimate North mission station garden, wrote in 1836: ‘Took up the Mill Stones and began to dress them. It is my first attempt at anything of the kind’. Davis was relieved when two years later he had ‘succeeded in procuring a useful mechanical man as Miller and Millwright’.1
How mills worked
Milling involves crushing the grain to separate the tough outer husk from the flour. This was done by mill stones powered by wind, water or steam. The most common form of mill in colonial New Zealand was the water mill, followed by windmills, and then steam-powered mills.
Mill stones were made up of interlocking pieces of quartzite or other very durable stone, secured by iron bands. The one at the bottom, the bedstone, sat fixed, while the top stone, the runner, rotated on it from a central shaft. The stones had a series of furrows, which left sharp edges that ground the grain. Centrifugal force sent the freshly-ground flour out to the edges through grooves cut in the stone.
Mills were tall buildings, often three storeys high. Grain was lifted to the top floor and dropped down on to the eye of the mill stone. When the flour emerged at the edges of the mill stone, it fell down a chute to a sack beneath.