sodium chloride (NaCl), is commonly said to be essential to life, and this is broadly correct although strictly speaking what is essential is the sodium which is present in some foodstuffs in one form or another.
Salty is a basic taste, which we are equipped to detect by some of the taste receptors in our mouths. Salt is also important in the preservation of food, especially by salting in pickles.
Since prehistoric times much effort has been devoted to obtaining salt for use with food. Its characteristic as an essential culinary and dietary building block has made it central of trade and exchange from earliest times (salt roads) as well as critical to many episodes of political interaction, whether of taxation and social control or revolt and rebellion.
One main source of salt is the existence of underground deposits, from which it can be mined. Examples are the famous salt quarries at Nantwich in Cheshire, those at Lüneburg in Germany, and many others in various parts of the world. The other great source, which is inexhaustible, is the sea (or other naturally occurring briny waters), which is made to yield salt by a process of evaporation.
Rock salt is what the salt mined from underground is called, whether it is literally mined in solid form (a practice now rare) or pumped up to the surface and then evaporated, to be crystallized to the desired degree of fineness. In some countries rock salt is used only in crude form for preservation purposes and for use in ice cream machines etc. However, rock salt which has been processed to the extent necessary to make it edible is sold for use in the kitchen and in small salt grinders at table. Its flavour will depend on any impurities left in it, and these in turn depend on the source.
Sea salt is the category to which belong many of the kinds of salt specially prized by connoisseurs. These salts are presented in attractive flakes or crystals. Some of the finest are French, e.g. from Guérande in Brittany and Noirmoutier, and some places on the Mediterranean coast; from Trapani in Sicily; from the coastal salt pans in Tunisia; from the salinas of Majorca; and from numerous sites in other continents. That of Maldon in England is also renowned.
Much sea salt is evaporated by artificial means. However, there are many places, especially in the Mediterranean region, where traditional techniques are used, the sea water being drawn into large shallow ‘basins’ and left to evaporate by the heat of the sun. As this process takes place, the salt formed on the bottom of the pans will be affected, often in colouring, by the nature of the clay or other substrate forming the bottom. Higher up in the layer of salt will be crystals which have not come into contact with the bottom and remain pure white; and it is these which constitute in France the more expensive fleur de sel.
The writer Jeffrey Steingarten (2002) has surveyed with enlightened irony the tremendous variety of salts now available, from the most expensive Oshima Island Blue Label of Japan to roasted salt from Korea. His experiments to determine whether the best salts were also the dearest or most exclusive did not wholly confirm the need to follow fashion.
What is usually called table salt is most used in kitchens (but see the next paragraph) or at table. This is a mass-produced, refined product which comes in very small grains, has been treated to ensure that it pours easily even in slightly damp conditions (‘when it rains, it pours’ was a slogan for one brand), and is sometimes iodized (i.e. iodine, a trace element lacking in some diets, has been added).
Salt in the kitchen may be of various kinds, often the same as table salt but in large or professional kitchens likely to be something of coarser texture—or indeed a small selection of different salts, since the various purposes for which salt is used in the kitchen do not all call for the same kind. One overriding rule, especially important at a time when people are advised to lower their intake of salt, is not to use too much at any stage in the preparation of a dish; and to remember that what is prescribed in older recipe books may be too much by more recent standards. Otherwise cooks have to profit from the numerous explanations and tips given in cookery books and from their own experience. Examples of specific points to bear in mind are:
Although salt is now readily available and inexpensive, it was formerly in some places a costly commodity which loomed large in the economic and political fabric of many cultures. Ayto (1993), having explained that the word for salt in most European languages (French sel, Spanish sal, German Salz, Russian sol') comes from a single Indo-European root, points out that:
Its cultural centrality is hinted at by such linguistic relatives as English salary, which originated as a Latin term for an allowance given to soldiers to pay for salt, Russian khleb-sol', ‘hospitality’, which means literally ‘bread-salt’, and of course the English expressions salt of the earth, ‘admired person’ (a reference to the Sermon on the Mount, ‘Ye are the salt of the earth,’ Matthew, 5: 13).
There is a considerable literature on these aspects, and much has also been written on the technology from prehistoric times to the present, and on salt in religion and folklore. Multhauf (1978), who, following in the footsteps of a 19th-century German author whom he admired, devoted an entire book to the subject, especially the scientific and technological aspects, while disarmingly stating that his ‘attempt to cover the subject in all times and places must be taken with a grain of salt’, probably did more than any previous author towards this laudable aim. However, the world history of salt by Kurlansky (2002) is now the best survey of the whole subject.
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.
Ayto, John (1993), The Diner's Dictionary, Oxford: OUP.
Dunoyer de Segonzac, Gilbert (1991), Les Chemins du sel, Paris: Gallimard.
Kurlansky, Mark (2002), Salt, London: Jonathan Cape.
Multhauf, Robert P. (1978), Neptune's Gift: A History of Common Salt, Baltimore: Johns Hopkins UP.
Steingarten, Jeffrey (2002), It Must've Been Something I Ate, London: Review.
