The term ‘flour’ which used to be spelled ‘flower’, originally meant the finest product (i.e. ‘the flower’) of the process of bolting meal from cereal grains. In modern times, when the term is used by itself, it is taken to mean Wheat flour. There are, however, many other cereal flours (Cornflour is one example) and also numerous kinds of flour made from nuts (e.g. Chestnut flour) or starchy vegetables (e.g. Cassava flour, Potato flour) or pulses (e.g. Besan flour).
In western countries the principal use of flour, understood as wheat flour, is in baking, especially Bread. Numerous different grades of flour may be had for this purpose:
Types of flour on sale include wholemeal and various shades of brown, from which some of the bran and germ has been extracted. Often the degree of extraction is stated; 81% is a typical figure. (The percentage refers to what remains, not what has been removed.) A flour described as ‘wheatmeal’ without a figure is likely to be paler, and ‘brown’ usually means very pale indeed. Coultate (1989) explains:
The bread-making properties of a flour are much improved by prolonged storage. Autoxidation of the polyunsaturated fatty acids of flour lipids results in the formation of hydroperoxides, which are powerful oxidising agents. One consequence is a bleaching of the carotenoids in the flour, giving the bread a more attractive, whiter crumb.
However, the most important of the beneficial effects of ageing are on the loaf volume and crumb texture. Over the first twelve months of storage of flour there is a steady increase in the loaf volume and the crumb becomes finer and softer.
Having explained the main meaning of ‘improving’ in relation to flour and that the principal improvements occur naturally if the flour is kept in store, Coultate goes on to explain how these natural processes can be replaced by similar but more rapid changes—brought about by chemical improvers.
For over 50 years it has been common practice to simulate the ageing process by the use of oxidising agents as flour treatments, at the mill or as additives at the bakery. The agents used have included:
The first two of these are usually described as bleaching agents, and the others as ‘flour improvers’, but there is no clear distinction between the two types of activity.
To make wheat flour the wheat must be ground by one means or another. The evolution of grinding and milling techniques began with the earliest known pestle and mortar, dating from about 10000 bc; this came from the Azilian culture of S. France, where it was used to grind pigments. No doubt pestles and mortars were subsequently used for grains, but the result they produce, although adequate for a Gruel or Pottage, does not really produce flour for bread.
In most places where a series of early food-grinding implements has been found, development can be seen to have proceeded in one of two ways. One was the larger mortar worked by two or more people pounding alternately with long-handled pestles, as is still seen in Africa. This is quicker, but does not give a finer grind. The other is a device in which the top stone, or pestle, rubs against the lower stone, or mortar, with a shearing effect on the grain which can produce flour as we know it. A large surface area is needed for efficiency, so the original bowl shape of the mortar is opened out into a flat form, generally at first with raised edges. This is set in front of the kneeling operator, sloping away from the body. A smaller, flat-bottomed stone is rubbed back and forth across the grain. The flour collects at the far end, where there is often a hollow.
Such devices, sometimes called saddle stones, are represented in ancient Egyptian paintings and tomb models and on Assyrian reliefs. Actual examples are found both in the old world and in America, where they were used for Maize. Early equipment of this type has also been excavated in the Balkans. A saddle stone grinds well but is slow, as well as exhausting.
Developments of the saddle stone, still manually operated but capable of greater output, appear to be concentrated in the E. Mediterranean; excavations on the Aegean island of Delos have yielded particular treasures. The lower stone was flattened, enlarged, and placed above waist height on a bench. One end of the upper stone was fixed to a pivot and both stones were ‘dressed’ with small diagonal grooves which crossed each other at an angle as the upper stone swept across the lower in an arc. Grooves were maintained in all subsequent mills.
From a reciprocating arc, the motion of the upper stone was converted to fully circular by placing the pivot at its centre, allowing it to rotate on the lower stone. To keep it centred, the lower stone was made conical. Grain was fed through a hole in the centre of the upper stone, and the action was driven by a handle that could be turned by two operators, usually women, sitting each side of the device (‘two women grinding at the mill’: Matthew 24: 41).
The small household quern (as this new device came to be called) grew into the classical world's ‘hourglass’ mill, so called because of its shape. The bottom was the conical grinder; its top was an extension of the upper stone to make a big funnel filled with grain. The upper stone was suspended on a pivot just clear of the lower one so that there was less tendency for the flour to be spoiled by stone dust and the stone was easier to turn. An hourglass mill was a big machine, at least as large as an oil drum, and was turned by slaves or a donkey.
Later progress in milling with stones depended on harnessing extra power. Once achieved, the stones could be enlarged and flattened, but the principles remained identical. Water power was perhaps first mentioned by Strabo in 150 bc, certainly by Vitruvius in 13 bc. It spread throughout W. Europe, bringing the potential of fine flour to most communities. Wind power was harnessed around the year ad 1000, allowing mills to multiply still further.
Such mills could grind any grain, which could be subsequently sieved or bolted. The Egyptians had used papyrus for sieves, later cultures horsehair or linen. Thus, from very early times, bread was ranked not only by its original ingredients (wheat, rye, or a mixture of various grains), but by its exclusion of unwanted bran.
The conventional stone mill, even when powered by steam engines and placed in series or groups in early industrial units created for the supply of large towns, for example in Paris, had a relatively low output. This was the case even though the French developed a system of twice grinding called mouture économique which greatly increased the extraction of white flour from stone mills. The problem was solved by the efficient, fast roller mill, first tried in Hungary in the 1820s, perfected in Switzerland in 1834, then quickly adopted all over Europe and America. Its multiple steel rollers not only ground the grain, but also separated the various fractions (bran, germ, endosperm) without the need for bolting. For the first time, truly white flour was available at a low price.
Objections to roller milling have been and are still raised, on various grounds. It is said that since it operates at high speed, it generates heat which damages enzymes in the flour. The very presence of metal is considered by some to be deleterious to the flour's original constitution. Others maintain that it creates a characterless, and nutritionally inert, flour by excluding important components, particularly the germ; or that it makes a nonsense of the concept of ‘wholemeal’ by removing the various fractions, then adding them back in at the end of the milling process. Stoneground flours are often preferred by people who take their bread seriously or are anxious to maximize flavour.
Alan Davidson was a distinguished author and publisher, and one of the world's best-known writers on fish and fish cookery. In 1975 he retired early from the diplomatic service—after serving in, among other places, Washington, Egypt, Tunisia, and Laos, where he was British Ambassador—to pursue a fruitful second career as a food historian and food writer extraordinaire. Among his popular books are Seafood of South-East Asia, North Atlantic Seafood, and Mediterranean Seafood. In 2003, shortly before his death, he was awarded the Erasmus Prize for his contribution to European culture.
