When we nip into the corner store for a loaf of bread we tend to forget what is involved in its manufacture. This article concentrates on the milling industry as the Vauxhall area had many windmills and it also had an early steam flourmill on the Thames just north of Vauxhall Bridge.

Wheat and corn together with other cereals have been and important source of food for both humans and farm animal since prehistoric times. At harvesting the cereal is threshed to separate the seed kernels from the stalks. Initially the hard grains would have been eaten whole but around 6,500 BC early civilisations discovered that flour made from the grain was very adaptable for all sorts of cooking. The flour was made by first separating the husk from the kernels using an inclined flat surface and rolling a long stone or piece of wood over the grains. Later the kernels would be pulverised, pestle and mortar style, by rubbing a curved stone back and forwards over them while they were in a shallow stone bowl to produce course flour. These stone bowls are called Saddle Stones by archaeologists.

The next development was around 1000BC when the quern was developed. A quern is a pair of flat circular stones that fit one on top of the other with the grain sandwiched in between. The upper stone is turned in circular fashion around the central axis so grinding the grain. Later developments included a hole to add new grain, a hand/stick hole near the outer edge to help turn the stones. A major improvement was the use of groves ("furrows") on the grinding surfaces which radiate out from the centre to the outer edge partly to help spread the grain evenly over the grinding surfaces ("lands"), partly to initially hold the grains whilst they are crushed and partly to introduce cooling air into the grinding process. The furrows also help move the resulting meal to the outside edge. The Romans used donkeys and slaves to power their mills, while the Greeks are thought to be the first to use water power and windmills start to appear in Europe during the 11th and 12 centuries.

From the 15th century the various English Corn Laws were officially introduced to help maintain adequate domestic supplies of grain and to stabilize the price at a profitable level. This was achieved by placing taxes on both import and exports and fixing quotas. The effect was to raise bread prices and give some home grain producers substantial financial advantages over foreign producers. The laws were unpopular and led to some very repressive legislation including restricting the right of assembly and the press. From 1815 UK producers had a virtual monopoly of supply till the Corn Laws were repealed by Robert Peel in 1846. Peel's free trade policies lead to an a rise in the quantity of imported wheat and the lowering of bread prices and so increase in the demand for good quality flour

In the mid 1870s in Hungary, a Bavarian engineer called Andr�s Mechwart introduced a new process of milling flour. He used a series of corrugated iron rollers driven by a steam engine. Roller mills could be smaller, more effective and produce smoother more consistent flour with better keeping properties at a lower price than either the water or wind powered mill. Around the same time new sorts of sieves and sieving techniques were introduced which also helped to improve the quality and consistency of the flour

Wheat grains are made up of an outer casing known as the husk, the wheat germ that is the embryo seed and the floury starch part that is called the endosperm. The old style mills had crushed the oily germ part of the grain together with the starch of the endosperm creating a yellow-brown flour which quickly went rancid. The new roller mills squeezed the endosperm out of its husk coating leaving the germ intact. When passed through various sieves the flour was separated from the germ and bran (husk) producing a whiter product that could be kept for months without noticeable deterioration.

The new roller systems had a major disadvantage - the machinery got hot and this damaged the nutrients in the flour, this was solved by water cooling the rollers. The scouring action of the rollers also damaged the starch but this was found to help speed up the way the flour reacted with the yeast and water during the bread making process.

When it arrives at a mill from the farm the wheat will inevitably contain course impuries such a stones, mud, glass and animal hair. The grain is cleaned usually by screening and air/gravity separation.

The pure kernels of wheat are then 'conditioned'. The conditioning, adding water to the grain, helps with the separation of the hard outer bran casing from the starchy (floury) endosperm, the result is then stored for about 24 hours to ensure that there is uniform moisture content. Batches of conditioned wheat are then blended together (gristed) so that they will make the flour of the type required.

The wheat is then milled to separate the bran, the germ and the endosperm and to produce uniform flour particles. The first set of mill rollers (the breaking rollers) separate the bulk of the bran and the germ from the endosperm. Result is then passed through various sieves to separate the various constituents Bran, Wheat Germ, Endosperm chunks and animal feed by-products. The endosperm chunks, together with small residual amounts of bran and germ, are passed through another series of rollers (the reducing rollers) to produce flour of the grade required. The result is again passed through various sieves to separate out the pure white flour from any residual bran etc.

Wholemeal flour is made by blending the white flour with the separated bran and wheat germ and has a characteristic brown colour. Wholemeal flour tends to make heavier breads that many people find less digestible, but it does contain much more roughage, than white flour. Doctors say that most people in Western Europe don't have enough roughage in their diets with the consequence of a higher risk of bowel cancer.