The story behind a loaf of bread

OLD AND NEW METHODS OF MILLING

The stone-age man's method of pounding wheat between two stones was not basically very different from the, method of grinding by millstones in a wind or watermill. In either case the bottom stone was fixed, and a grinding movement by the top stone was the required action to produce ground meal. The stones were round, the bottom one fixed as we have said, and the top stone, or runner, was balanced on a spindle which could be raised or lowered, making the space between it and the bottom stone as narrow or as wide as the miller wanted. Both stones were corrugated, so that when the top stone was running, the wheat between it and the bed was scraped rather than bruised. The wheat to be ground entered the mill by a hole in the top stone, and was carried out towards the edge, leaving in the form of a meal by holes round the outside of the bed. By raising or lowering the top stone, the meal could be made as fine or as coarse as required.

To obtain white flour from this meal, it was sifted through sieves of different mesh, the finest sieve made of very strong silk. Nowadays in Britain stone mills are of course not used much for flour-making; only a few are still used for wholemeal flour and speciality millers.

An attractive-looking old windmill. Watermills and windmills were in universal use for over seven hundred years. Afew have been preserved as historic monuments.

Watermills for grinding flour were of two varieties; in the first kind the wheel turned horizontally in the stream, its shaft turning the millstone directly, without any gears. The second type had its wheel standing upright (most of you have probably seen one of these watermills), and the shaft at right-angles to the stones, moving them by means of a system of cogs.

The windmill made its appearance at the end of the twelfth century; as it depended for its working on the amount of wind available, it was not by any means an efficient machine. For over 700 years these attractive buildings with their long sails were used for grinding corn for people and for cattle-feed. There are still one or two of them preserved in various parts of our country.

The plant of a modern flour mill has four main functions:

1. To store a reserve of wheat.
2. To remove all the impurities from the wheat and prepare it for milling.
3. To mill the wheat and separate flour from the bran and skins of the wheat.
4. To store the milled products before dispatch.

You have no doubt seen the wheat stores or silos at a flourmill. They are tall buildings housing a number of large cylindrical bins. They are 60 to 90 feet high and may each hold 1,000 tonnes of grain. The silo is equipped with mechanical elevators for dealing with wheat wich invariably arrives by road to the mill. It is also equipped to weigh the wheat, to clean it, in part, of impurities to a safe moisture-content before storage

The cleaning section or screen room draws wheat from the silo. Here wheat is first cleaned on sieves which removes all the impurities different in size from the wheat grain. Magnets next remove any fragments of iron or steel. Further equipment then take out impurities similar in size but different in shape from the wheat grain, such as foreign cereals or round seeds.

An old-fashioned watermill. The shaft of the wheel is at right-angles to the millstones,. they are turned by means of a system of cogs.