The Salt of Portugal

During Portugal’s ‘lockdown’ we spent two months in Tavira, a small historic settlement at the mouth of the Rio Gilão where it feeds into the Algarve’s extensive Ria Formosa waterway. We would ‘exercise’ ourselves daily by walking in between and along its salt pans. These large and prolific salt farms, rectangular in shape, range from as far as Faro to the west, to Castro Marim on the Guadiana River, Portugal’s south eastern border with Spain.

Salt (NaCl sodium chloride). We know it as a seasoning for our cuisine, a preservative, and as salt-lick blocks for livestock.

These days, it is also used in the production of many other chemicals.

Since mankind first walked on this earth salt has been highly valued, in fact it was once one of the most-valuable and much-traded products.

Photo credit: pinterest.com

Salt caravans have been carrying crude rock-salt across central Africa since time immemorial. Broken out from ancient sedimentary salt beds it is first shaped into convenient slabs then strapped, pannier-style, onto donkeys or camels and transported to fabled trading posts such as Timbuktu and Mekele. This traditional harvesting process and mode of transportation continues today. The ancient sedimentary beds, found in in Mali’s desert region¹, Ethiopia’s Danakil Depression², and in the Sahara desert as well as parts of greater Asia, are vast and seemingly inexhaustible. They are, however, finite.

Contemporaneously, coastal dwellers in temperate climates found they could harvest a constantly renewable source from the sea by constructing salt ‘pans’.

These ancient and extensive pans can be seen today in Namibia’s Walvis Bay³ and much further to the north – on the Iberian Peninsula’s southwestern coast where, in the process of colonisation, commerce and settlement the Phoenicians, followed by the Greeks, Romans, and then the Moors utilised the region’s idyllic features to develop this ancient venture. They also grasped the region’s potential for wide-scale production of much sought-after olives, carob, corn and grapes. But that’s another story.

It was in this latter region, during the Covid-19 global panic that we had the leisure to explore the extent of Portugal’s salt pans on the Algarve province’s south coast. Its favourable climate and topography: broad river deltas and thousands of hectares of low-lying coastal flatlands with sheltering off-shore dune-islands, have long proven ideal for salt production.

With only wading and water-birds’ cries to accompany us we could turn our face in whichever direction we desired and walk for hours in splendid solitude under expansive summer-blue skies. On the chequerboard ‘tracks’ of the salt pans’ raised median mounds – used both by the pans’ workers and a few locals out for exercise – we had unfettered access to this tidal environment, enjoying the rich hues of the salt-tolerant bush and flora, large flocks of (very shy) pink flamingos, wading birds and the small, omnipresent mud crabs.

Photo credit: tavira.pt

Nature, time, weather and tides; the process of coastal salt harvesting involves integration with all these factors.

The result is a striking palette of colours.

While the pans when first flooded retain the colour of the bottom, under evaporation they increase salinity and algae starts to grow and flourish causing the water to take on a greenish hue. As flow continues and additional evaporation takes place the salinity increases causing the algae to die and become brown. The pink colour which often occurs is caused by another microorganism, a single cell life-form called halophilic bacteria.

These thrive in high salinity brine. The cell membranes contain carotenoid pigments which give the crystals the pink-red color. The dark color increases the absorption of sun light which increases the temperature which in turn usefully increases evaporation and salt production.

The pans, all in different phases of enrichment and interconnected until deemed ready for final ‘salination’, alternately shimmer, glisten, or are glazed, ice-like.

Some have the makings of a sugar-like frosted surface – the much vaunted ‘flor de sal’.

Some pans are left fallow and dry; others are left free-flowing to the ocean tide and are inhabited by small fish – more food for avian raptors. It is a very busy, cyclical and timeless natural environment.

¹ https://www.youtube.com/watch?v=mZ1eQ99Triw
² https://www.youtube.com/watch?v=PgDiW2ELx7k
³ https://www.bbc.com/news/av/business-48201024

For those of you who have a deeper interest in the source of salt I would keenly recommend this site:
http://www.bradshawfoundation.com/africa/tuareg_salt_caravans/index.php

Unless credited, all photos by JC & R Watkins

NOTE: While being keen followers of the Portuguese food website “Salt of Portugal”, we have no affiliation to it.