Thursday, July 16, 2015

A Brief History of Foods: Salt

"A Brief History of Foods" is mostly aimed at improving my knowledge on the origins of the foodstuffs commonly eaten in Britain throughout its long history.  Over the years I have been surprised to learn how few of our commonly used ingredients are actually native to these shores, and just how many were introduced, when and by whom.  Perhaps you too might discover something new and quite interesting.
Salt is a chemical compound of sodium and chloride (NaCl) and is an essential nutrient, the amount of which in the diet has a direct influence on health. Today, it is almost universally accessible and relatively cheap. Most of us probably take salt for granted, but it was not always the case. It has been central part of human history for thousands of years largely due to salt's ability to preserve food. It was this property that effectively removed man’s dependence on the seasonal availability of food and increased the opportunities to travel long distances.

Some of the earliest evidence of salt processing dates to around 6,000 years ago, when people living in Romania were boiling spring water to extract the salts; a salt-works in China has been found which dates to approximately the same period. Salt was prized by the ancient Israelites, the Greeks, the Romans, the Byzantines, the Hittites and the Egyptians
[1]. As such salt became a highly prized article of trade and was transported by boat across the Mediterranean Sea, along specially built salt roads - some of the earliest dating to the Bronze Age, and across the Sahara in camel caravans. The scarcity and universal need for salt has led nations to go to war over salt and use it to raise tax revenues. Salt is also used in religious ceremonies and its cultural significance has led some commentators to argue that it was a contributing factor in the development of civilisation.

In the early years of the Roman Republic, with the growth of the city of Rome, roads were built to make transportation of salt to the capital city easier. The most obvious example is the via Salaria , literally the “salt road”, that leads from Rome to the Adriatic Sea. The Adriatic, having a higher salinity due to its shallow depth, had more productive solar ponds compared with those of the Tyrrhenian Sea, much closer to Rome. It is commonly believed that, at certain times, Roman soldiers were paid with salt, hence the word “salary”, but this is unlikely. The Latin word salarium does seemingly link employment, salt and soldiers, but the precise link is far from clear. This misunderstanding probably stems from the Roman historian Pliny the Elder, who stated as an aside in his Natural History's discussion of sea water, that "[I]n Rome...the soldier's pay was originally salt and the word salary derives from it...".[2] Today it is more generally accepted that, although Roman soldiers were typically paid in coin, the word salarium is derived from the word sal (salt) because at some point a soldier's salary may have been an allowance for the purchase of salt[3] or the price of having soldiers conquer salt supplies and guard the salt roads, i.e. via Salaria, leading to Rome.

During the late Roman Empire and throughout the Middle Ages salt was a precious commodity carried along the salt roads into the heartland of the Germanic tribes. Caravans consisting of as many as forty thousand camels traversed four hundred miles of the Sahara bearing salt to inland markets in the Sahel, the semi-arid zone that stretches across the south-central latitudes of Northern Africa between the Atlantic Ocean and the Red Sea. Such markets traded salt for slaves: Timbuktu, for example, was a huge salt and slave market. Elsewhere, in China for example, salt was both a driver of technological development and a stable source of revenue for the imperial government.
Salt pan in Death Valley National Park, USA

There have been two main sources for salt: sea water and rock salt. Rock salt occurs when water in enclosed lakes, playas (or salt pans) and seas evaporates leaving behind vast beds of the mineral, some of which can be up to 350 metres thick. In the United States and Canada, for example, extensive underground salt beds extend from the Appalachian basin of western New York through parts of Ontario and under much of the Michigan basin. While in the United Kingdom underground beds are found in Cheshire and around Droitwich in Worcestershire.

On an industrial scale, salt is produced in one of two principal ways: the evaporation of salt water (brine) or by mining from underground beds. Evaporation can either be solar evaporation or using some heating device to produce salt crystals.

In the correct climate it is possible to use solar evaporation of sea water to produce salt. Brine is evaporated in a linked set of ponds until the solution is sufficiently concentrated by the final pond so that the salt crystallises on the pond's floor. This is the method recorded by the Roman authors where, in order to aid natural evaporation, shallow rectangular ponds (multifidi lacus) were dug, divided from one another by earthen walls. The opening and closing of sluices (cataracta) allowed sea-water into these pools through canals. The water was more and more strongly impregnated with salt as it flowed from one pond to another. According to Pliny the Elder, when reduced to brine (coacto umore) it was called by the Greeks ἅλμη, by Latin speakers salsugo or salsilago, and by the Spaniards muria. In this state it was used by the Egyptians to pickle fish[4], and likewise by the Romans to preserve olives, cheese, and meat[5]. As the brine left in the ponds crystallised, a salinator had the job of raking out the salt and laying it in heaps (tumuli) upon the ground to drain.

Solar evaporation salt works

Throughout the Roman Empire salt-works were commonly public property, but were leased by the government to the highest bidder. The first salt-works are said to have been established by Ancus Marcius at Ostia.  The important point, however, is that energy is required to evaporate the water or mine the salt. In these cases, the costs of fuel and labour have an impact on the cost of the end product of salt. The cost meant that, in the classical Mediterranean world at least, there was greater reliance on the use of fish sauce, or garum, as a cheaper more accessible substitute for salt.

As for the solution mining of salt, the earliest examples of pans date back to prehistoric times where the pans made of a course ceramic known as briquetage. Later examples were small pans about one metre square (3 ft square) made from lead and using wood as a fuel. After the Middle Ages pans started to be made from iron, firstly in pans measuring about 2.1 m (7 ft) by 2.4 m (8 ft). Over time pans have gradually increased in size until they are typically 6.1 m (20 ft) wide by 9.1 m (30 ft) long. Regardless of their size, brine would be pumped into the pans and concentrated by the heat of the fire burning underneath. The change from lead to iron pans coincided with using coal instead of wood to heat the brine. As crystals of salt formed these would be raked out and more brine added.

In the second half of the 19th century, industrial mining and new drilling techniques made the discovery of more and deeper deposits possible, increasing mined salt's share of the market. Although mining salt was generally more expensive than extracting it from brine via solar evaporation of seawater, the introduction of this new source on an industrial scale had the overall effect of reducing the price of salt.
Bread and Salt: a traditional eastern European welcome

Today one of the largest salt mining operations in the world is at the Khewra Salt Mine in Pakistan. The mine has nineteen storeys, eleven of which are underground, and 400 km (250 miles) of passages. The salt is dug out by the room and pillar method, where about half the material is left in place to support the upper levels. Extraction of Himalayan salt is expected to last 350 years at the present rate of extraction of around 385,000 tons per annum.[6] In 2002, total world production (of sodium chloride in general, not just table salt) was estimated at 210 million tonnes[7].  Five years later global production had increased by 12% proving salt continued inestimable value to us all.

1. Bloch, D. "Economics of NaCl: Salt made the world go round", Mr Block Archive. Retrieved 2006-12-19.
2. Pliny the Elder, Natural Histories XXXI
3. Ibid.
4. Herodotus, The Histories, II.77
5. Cato the Elder, on Agriculture, 7, 88, 105

6. Pennington, M. (25 January 2005), "Pakistan salt mined old-fashioned way mine", The Seattle Times.
7. Feldman, S. R. (2005). "Sodium Chloride". Kirk-Othmer Encyclopedia of Chemical Technology.

Wednesday, July 15, 2015

A Brief History of Foods: Broccoli

"A Brief History of Foods" is mostly aimed at improving my knowledge on the origins of the foodstuffs commonly eaten in Britain throughout its long history.  Over the years I have been surprised to learn how few of our commonly used ingredients are actually native to these shores, and just how many were introduced, when and by whom.  Perhaps you too might discover something new and quite interesting.

Broccoli (Brassica oleracea italic) is a cultivar of wild cabbage, which originated along the northern and western coasts of the Mediterranean and Asia Minor.  Wild cabbage may have been domesticated by the Etruscans, who first settled in the northern and central portion of Italy in about 1100 BC.  That domestication eventually produced wildly different cultivars, including broccoli, cauliflower, cabbage, kale, kohlrabi, and Brussels sprouts, all of the mustard family (Brassicaceae).

The Italian word “brocco” means sprout, bud, or shoot, and derived from the Latin brachium meaning an arm or branch.  However, Roman references to a cabbage-family vegetable that may have been broccoli are not entirely clear.  The Roman natural historian Pliny the Elder writes of a vegetable fitting well with the description of broccoli and most classical food historians recognise broccoli in the cookbook of Apicius.

As its name suggests, broccoli was eaten in Italy long before anywhere else.  It is first mentioned in France in 1560, but broccoli was still so unfamiliar in Britain that Philip Miller's Gardener's Dictionary of 1724 referred to it as a stranger in England and explained it as "sprout colli-flower" or "Italian asparagus”.  So, although the Roman cultivated and ate broccoli, it was not until the 1700s that this particular vegetable was widely introduced to Britain and America.

Sunday, July 05, 2015


"A Brief History of Foods" is mostly aimed at improving my knowledge on the origins of the foodstuffs commonly eaten in Britain throughout its long history.  Over the years I have been surprised to learn how few of our commonly used ingredients are actually native to these shores, and just how many were introduced, when and by whom.  Perhaps you too might discover something new and quite interesting.

With the first week of the All England Lawn Tennis and Croquet Club's 2015 Championship in Wimbledon all but over, it got me thinking about strawberries (and cream) and where this iconic summer treat originated.  As usual, not all is as clear cut as you might think.  To give you a flavour of what I mean, back in 2010 Heather Driscoll-Woodford, writing for BBC Surrey[1], suggested Wimbledon's strawberries and cream had Tudor roots.  It is to Cardinal Thomas Wolsey, Lord Chancellor and King Henry VIII's right-hand man, that the credit is first given to combining berries with diary.

Although, as we shall see, strawberries had been around in England and elsewhere since the Ice Age, the idea of teaming them with a dollop of cream had not occurred to anyone.  Yet someone in Wolsey's Hampton Court Palace was apparently inspired to do so.  History, however, fails to name which of the many cooks it was, toiled for hours in the hellishly hot kitchens to produce the food needed to feed 600 people twice a day, who first created the dish.  So, rather unfairly, Cardinal Wolsey is given the credit for this simple combination enjoyed as a treat by millions worldwide.

Commonly known as strawberries for their edible fruits, the generic term for these flowering plants is actually Fragaria. Surprisingly, strawberries are part of the rose family, Rosaceae, and there are more than 20 described species, with many hybrids and cultivars[2]. Strawberries are not true berries[3]. The fleshy and edible part of the fruit is a receptacle, and the parts that are sometimes mistakenly called "seeds" are known as achenes[4]. Such achenes contain a single seed that nearly fills the edible outer layer of the fruit (known as the pericarp), but does not stick to it. The seed-like appearance comes from the hardening of the wall of the seed-vessel that encloses the solitary seed so closely as to seem like an outer coat.
Home growing wild strawberries

The first garden strawberry was grown in Brittany during the late 18th century[5].  Before this, wild strawberries and cultivated selections from wild strawberry species were the common source of the fruit.  Indeed, man’s consumption of wild strawberries has been dated to the Neolithic based on the evidence from La Marmotta, a Neolithic site on the shores of a volcanic lake, Lago di Bracciano, 32 km (20 miles) northwest of Rome.  Similarly, we have evidence for strawberries being gathered from the wild before 6,000 BC at Grotto dell’Uzzo in Sicily.

Although a huge leap forward in historical terms, by the classical period Roman authors were mentioning strawberries for their medicinal uses.  And that’s where the story seems to stall until the 1300s when the French are credited with first bringing the wild strawberry from the forest to their gardens where they would be propagated asexually by cutting off the runners.   The French King Charles V (r. 1364 to 1380), for example, is said to have had 1200 strawberry plants in his royal garden.

In the early 1400s western European monks were using the wild strawberry in their illuminated manuscripts and, echoing the ancient Roman literature, the entire strawberry plant was being used medicinally to treat depressive illnesses.

By the 1500s references to the cultivation of the strawberry become more common.  People were still using it for its supposed medicinal properties, but now botanists began naming the different species.  In England the demand for regular strawberry farming had increased by the mid-1500s.  Written instructions for growing and harvesting strawberries appeared in 1578 and by the end of the century three European species had been cited; Fragaria vesca, Fragaria moschata, and Fragaria viridis.

The cultivation of the modern strawberry, however, had to wait until the 1600s when Fragaria virginiana was introduced from eastern seaboard of North America to Europe.  The new species gradually spread through the continent, but it was still essentially a wild strawberry very different from the modern hybrid.  It was a French expedition to Chile, in 1712, that led to introduction of a plant with female flowers, Fragaria chiloensis or the Chilean strawberry.  Once again, although these new plants grew vigorously in Europe, they still produced no fruit.  Until that is, in 1766, when it was discovered that female plants could only be pollinated by those plants that produced large fruit, such as Fragaria moschata, Fragaria virginiana, and Fragaria ananassa.  European growers finally understood that strawberry plants produced either male-only or female-only flowers, and it was this realisation that paved the way for the cultivation of the common strawberry hybrid that we have today.

[2]  A cultivar is an assemblage of plants that (a) has been selected for a particular character or combination of characters, (b) is distinct, uniform and stable in those characters, and (c) when propagated by appropriate means, retains those characters.
[3] Esau, K. (1977), Anatomy of seed plants, John Wiley and Sons, New York.
[4] Ibid.
[5] Welsh, M. (2008) "Strawberries",

Thursday, July 02, 2015

A Brief History of Foods: Pepper

"A Brief History of Foods" is mostly aimed at improving my knowledge on the origins of the foodstuffs commonly eaten in Britain throughout its long history.  Over the years I have been surprised to learn how few of our commonly used ingredients are actually native to these shores, and just how many were introduced, when and by whom.  Perhaps you too might discover something new and quite interesting.
Long pepper (Piper longum), sometimes called Indian long pepper, is a flowering vine in the family Piperaceae.  It is cultivated for its fruit, which is usually dried and used as a spice and seasoning.  Long pepper has a similar, but hotter, taste to its close relative Piper nigrum from which black, green and white pepper are obtained; the latter is actually just a ripened form of black pepper.  The word “pepper” itself is derived from the Prakrit word for long pepper, pipali.

The fruit of the pepper consists of many minuscule fruits - each about the size of a poppy seed - embedded in the surface of a flower spike that closely resembles a hazel tree catkin.  Like Piper nigrum, the fruits contain the alkaloid piperine, which contributes to their pungency.  Another species of long pepper, Piper retrofractum, is native to Java, Indonesia.  The fruits of this plant are often confused with chilli peppers, which belong to the genus Capsicum and were originally from the Americas.

The first reference to long pepper is found in the ancient Indian textbooks of Ayurveda where its medicinal and dietary uses are described in detail.  It became known in classical Greece around 400 BC where it was mentioned by the playwrights Antiphanes, Eubulus, Alexis and in a Hippocratic text, although Hippocrates discussed it as a medicament rather than a spice.  Among the Greeks and Romans, and before the European rediscovery of the Americas, long pepper was an important and well-known spice being imported from northeastern India.  In fact, pepper was the quintessential spice of the Indian Ocean trade whereby large quantities of Roman gold and silver coins made their way into the markets of India.  So important was this trade that the Roman treasury stockpiled pepper, especially in the horrea piperatoria ("pepper warehouses") built by Emperor Titus Flavius Caesar Domitianus Augustus (Domitian), as an alternative form of currency.  For those who could afford "exotic" pepper, Apicius mentions it over 400 times.

The ancient history of black pepper is often interlinked with (and confused with) that of long pepper even though Theophrastus distinguished the two in the first work of botany.  The Romans clearly knew of both but, confusingly, often referred to either as just piper; Pliny erroneously believed dried black pepper and long pepper came from the same plant.  Long pepper (piper longum) is the hotter of the two, however, with Galen comparing its heat to that of ginger.  It fetched twice the price of black pepper in Roman times.

Round, or black pepper, began to compete with long pepper in Europe from the 12th century and had largely displaced it by the fourteenth.  The quest for cheaper and more dependable sources of black pepper fuelled the Age of Discoveries; only after the discovery of the American Continents and of chilli pepper, called by the Spanish “pimiento”, employing their word for long pepper, did the popularity of long pepper fade away.  Chilli peppers, some of which, when dried, are similar in shape and taste to long pepper, were easier to grow in a variety of locations more convenient to Europe.

Today, long pepper is quite a rarity, but it still can be bought through more specialised food outlets.