History of Flour

Undoubtedly the cereal grains would first have been eaten raw by the ancient man. As a food they were doubly valuable because in the dry state they could be stored from year to year. This storage aspect is still important as one of the reasons for the large international trade in grains. Raw wheat is not particularly palatable and man next discovered how to soak and boil the grains.

But the really important discovery was that the grain could be ground to make a meal. Some native tribes still make meal by pounding the grain. However, grinding is more efficiently carried out by rubbing wheat grains between two stones - a small stone held in the hand and a large "saddle" stone lying on the ground. Such a device requires a lot of hard work, but its' efficiency was improved by the cutting of grooves in the faces of the stones, and by fixing the upper stone to a lever that reduced the apparent effort required. Backwards and forwards motion is very wasteful and a real advance came with the rotary motion - the quern consisted of two round flat stones one above the other. The upper stone was turned by a wooden handle, wheat was trickled in through a hole in the centre and came out around the edge.

Up to now the grinding of meal had mostly been carried out in the home. During the Roman times the first milling "industry" probably arose, with an increase in the size of the mill stones and a change in their shape. With the increased size, animals as well as slaves were used to turn the stones. The "industrial" milling process was carried out in the bakery. It was during this era also that water power was used to drive the millstones by means of a paddle wheel. The use of wind power, in the form of a windmill, is a much more recent innovation, dating only from mediaeval times. The remains of many watermills and windmills are to be found around the country, for this was the normal method of driving mills in New Zealand up to around 1900.

Very clearly in history it must have been discovered that a more palatable product could be made by sieving the ground meal. The whiter flour thus obtained by the use of sieves made of horse hair was called "pollen" (meaning fine powder) by the Romans. The especially fine grade they called "flos" a word that meant the best part of anything. They used the same word for a flower - it being the best part of the plant. So our words flour and flower originally were the same. The Dutch word for flour is "bloem" - easily recognisable as our word "bloom".

Very little change took place in the actual milling process between Roman times and the 1700's, though considerable progress was made in the associated mechanics - the methods of driving the the stones and their setting and feeding. Many of today's mechanical devices were invented by the millwrights. Most impotant perhaps was the centrifugal governor, patented in 1797 and later very successfully adapted to the steam engine. The later versions of wind and water mills incorporated many automatic controls, together with alarm systems to call the miller when things were going wrong - the millers might said to be the originators of automation.

The next major developments came during the 1700's and 1800's. They were "high" milling processes and improved methods of separating the constituent parts of the ground stocks.

High milling is said to be a Hungarian invention; certainly it reached its highest state of development in Hungary, though when introduced to America it was called the "French" system. It involved the use of several pairs of millstones with coarse grooves and a wide gap on the first pair, hence the name "high". Finer grooves and narrower gaps were set on succeeding pairs of stones. The use of more stones meant more handling of stocks and this led to the development of the "automatic" mill, in which the hard work of transferring grain and stocks was done by machines rather than by hand. The vertical arrangement of the mill dates from this time, the grain being initially being raised to the top of the mill building, and then flowing downwards through successive machines.

Many more machines were introduced to separate the constituent parts of the stocks. From the early hand-shaken sieve the modern plansifter has been developed, whilst at the same time it was found convenient in mechanising sifting to use a cylindrical reel type of sieve, from which the centrifugal reel was developed. In the 1700's some millers had used air currents in wheat cleaning and in cooling stocks but in the early 1800's it was realised that stocks could be separated in this way. The Hungarians also discovered that bran could be floated to the surface of a tub of meal and so scraped off. This layering principle was combined with the use of air currents to give the modern purifier. Thus the modern stock separating devices were discovered before the great revolution in milling.

This revolution was the substitution of steel rollers in place of the flat mill stones. The first successful roller mill operated in Switzerland in 1834 and within five years such mills were operating in many parts of central Europe. However, because of considerable vibration the rolls were placed in the lower floors of the mill, thus accounting for their current position in modern mill layouts. The use of metal break rolls spread to Britain in the 1870's and to North America in the 1880's. The use of smooth rolls for the reduction part of high milling was a discovery of the 1870's that was very quickly put into wide use, replacing the the millstones that had hitherto been used for that purpose. Porcelain rolls were used for a time, but were eventually replaced by steel.

So by 1900 most of the common machines of the present day mill had been developed. The handling of materials in sacks and buckets had been replaced in the automatic mill by mechanical transfer with bucket elevators and worm conveyors. Since the Second World War another revolution in milling has taken place with the introduction of pneumatic conveying of stocks from one machine or place to another. Along with this has come better dust collection systems, with high efficiency filters and cleaning mechanisms.