Salt: A World History by Mark Kurlansky

Salt has shaped our culture just as much as gold. relishes its savoury past

Salt sustains life and feeds dreams. You taste it in blood, tears and sweat, for the body is a sodium-reactor, dissolving and recycling salt. The mineral is indispensable; yet most metabolisms seem to crave far more than is necessary. It is the only rock we eat. It makes soil barren, yet symbolises fertility. It kills bacteria and suppresses decay. It seals covenants and dries documents. It attracts myths and inspires mystique. It is the stuff of illusions as well as the staff of life. It has been revered by every culture and reviled by modern dieticians. It is abundant but hard-won: where there are no mines or salt-pans, it has to be coaxed from plants such as coltsfoot or samphire.

The big story in the history of salt is of the increase in our intake: from less than 700mg daily per person in paleolithic times to nearly 4,000mg in the developed world today. Alarmed by this trajectory, low-sodium evangelists have blamed heart disease, fatally high blood pressure and even asthma on over-indulgence in salt.

Surprisingly, this story does not feature in Mark Kurlansky's new book. Nor does the ensuing controversy about the gravity of the salt-hazard. Yet the drive for more salt, the struggle to control supply, and the high values which go with high demand have been major influences in global history. Some effects are well known: how salt-taxes made medieval monarchies, triggered the French Revolution and fuelled India's independence movement. Kurlansky gives a gripping account of Gandhi's famous "march to the sea" in search of untaxed salt.

These episodes seem of slight significance, however, compared with the economic revolutions salt has caused, and the routes of cultural exchange it created. Two great salt-deficient markets warped world history into new directions: the gold-rich west African market in the late middle ages and the huge food-salting industry of northern Europe – especially of the Netherlands – in the 17th century. The first of these sustained the medieval gold trade, the second profoundly influenced the course of early long-range maritime imperialism.

Salt was the chief commodity that kept the trans-Saharan gold trade going in the middle ages. When Ibn Battuta, the widest-ranging pilgrim of the time, crossed the Sahara in 1352, he accompanied a salt caravan from the mining center of Taghaza. The scenes he described can still be witnessed today because the densely populated Niger valley still relies on salt imported by traditional means. Taghaza, to Ibn Battuta's sophisticated Maghribi mind, was "a village with no attractions. A strange thing about it is that its houses and mosque are built of blocks of salt and roofed with camel skins. The Blacks trade with salt as others with gold and silver; they cut it in pieces and buy and sell with these." Taghaza was squalid, but its trade was worth millions.

In northern Europe, the salt shortage was even worse than that of bullion – especially when population began to rise in the 16th century. Changing taste played a part. The Renaissance transformed courtly cookery, as it transformed other arts. In the kitchen, reversion to ancient texts and Graeco-Roman sources of inspiration demanded the abjuration of Arab influence.

When Renaissance cooks tried to revive habits of antiquity they discarded the "Moorish" palette of the culinary artist, with its gold hues, fragrant odours and sweet tooth. The result was a new "salt-acid" repertoire of flavors, supposedly derived from ancient Rome, which came to dominate Western cookery. Roman food's reputation for saltiness derives from the ubiquity in Roman recipes of the fish-sauce called garum or liquamen – made from red mullet, sprats, anchovies and mackerel, mixed with entrails of other large fish, salted, exposed to sun, sieved and stored. The best quality sauce, however, was not excessively salty and used, for instance, to freshen over-salty sea-urchins.

More significant for the new importance of salt in Europe was the growing wealth and population of particular regions, especially Scandinavia and the Netherlands. In the early 17th century, while well-known nutmeg wars were fought between Dutch and English merchants for access to rare and luxurious "East Indian" spices, a less glamorous but more intense drama unfolded in the west: the Netherlanders' efforts to secure their salt supply for processing herrings, butter and cheese..

Poland, France and parts of the Baltic had extensive salt deposits, but these were expensive and delivery was unreliable in time of war. The most coveted supplies were controlled by the Spanish monarchy, in Portugal and the Caribbean, where salt suited to herring was produced. Throughout the 17th century, fluctuations in the Netherlanders' salt supplies determined the rhythms of war and peace with the Spanish and Portuguese empires and, therefore, the ebb and flow of prosperity in the Dutch "Golden Age".

Mark Kurlansky should not be condemned for missing out or marginalising these big historical themes. His book is intended as a collection of fascinating facts about salt – some good enough to sprinkle on birds' tails. It is not really "a global history": Europe and the US crowd the rest of the world into a few pages. China and India feature only in the usual contexts: adding colour in remote antiquity and evoking pity in colonial times, though there is an interesting middle-eastern excursion on magnesium extraction in the Dead Sea. This is infotainment in book form. It is well paced, endlessly engaging, full of amusement and instruction. Morton's Salt deserves to be as famous as Morton's Fork: a business elevated to greatness by a triumph of sloganising ("When It Rains, It Pours").

Kurlansky's evocation of the old anchovy industry of French Catalonia is charming. His explanation of the streetplan of Syracuse, New York, is fascinating. It is thrilling to accompany him among the sinkholes of Cheshire. His salty accounts of the American Revolution and Civil War excite the appetite. He sprinkles his pages with delightfully oddball recipes, which will make the book indispensable for any cook whose ambitions include salted mullets' roes, Irish corned beef, or "huiguorou" (Sichuan ham). But some – like Apicius's recipe for stewed flamingo – are mere exotic padding. My favourite, which captures the arduous history of salt as a preservative, is from the Confederate States Almanac for 1865: "TO KEEP MEAT FROM SPOILING IN SUMMER: Eat it early in the spring."

Felipe Fernández-Armesto's book 'Food: a history' is published by Macmillan