Every home has some salt in it, whether in the kitchen cupboard or on the table, next to the pepperpot.

Many people know that salt had been a rare commodity, and was used as part of a Roman soldier’s wages back in the day. Their monthly allowance was called ‘salarium’, from the Latin word ‘sal’ for salt. Eventually, the word became ‘salary’, the word we now recognise as a payment for working. A soldier doing a good job was said to be ‘worth his salt’, a saying that is still around today.

The majority of salt is mined around the world from deep underground and is usually in the form of halite or rock salt. Before the Industrial Revolution, salt mining was by hand, and a dangerous occupation. Because rapid dehydration caused by contact with the salt caused accidents by excessive sodium intake and as the life expectancy of miners was low, poor old slaves or prisoners were often used as miners, presumably as the length of their lives were deemed unimportant. However, today salt mining is considered one of the least dangerous methods of mining due to modern mining methods and machinery.

Another method of producing salt is by evaporation, and salt produced in this manner is particularly sought after in culinary circles.

Portugal’s coastline, exposed to hot, dry winds and high temperatures during summer, has enabled the production of natural salt from evaporation ponds. Bright white, the salt is harvested as it is deposited on the top of the water just prior to sinking, and is similar to the French salt - Fleur de Sel - but known in Portugal as Flor de Sal – Flower of Salt. When the salinity in these shallow salt pans reaches super saline conditions, ultra-white crystals balance themselves on the water’s surface – translucent, crunchy, ultra clean, crisp and delicate in texture, this form of salt has a unique flavor. In Portugal, it is also known as salt cream, because it must be gently skimmed away from the surface, like cream from milk. This unique salt can form in a matter of hours, unlike traditional salt, and can even be harvested twice a day if the weather conditions are just right.

Salt was used as a preservative, and archaeological evidence of fish preservation exist dating back to the Phoenicians in the 9th Century, and salt was probably intensively used during the Roman period, as there are many archaeological remains of fish salting settlements in southern Portugal. At the start of the 10th Century between the Minho and Vouga Rivers, the exploitation of salt was prospering, and Portuguese salt was considered a quality product in various parts of the world. It became an important export for the national economy, and by 1178, the Rio de Aveiro became particularly important by creating enough salt for both the whole country and for exporting. This particular area resulted in the decline and almost complete disappearance of salt production in other parts of Portugal.

The rectangular pools are known as ‘salinas’, and the men who worked the salinas are called ‘Marnatos’, and with hand-crafted butterfly-shaped sieves called ‘barboletos’ they skim the delicate salt crystals from the surface. Their expertise tells them when they are perfect for harvesting by the sound the sieve makes. Traditional sea salt crystallizes at the bottom of the salt pan and is raked into piles with a wooden rake called a ‘rodo’ every 3-4 weeks.

1000 litres of fresh sea water can give around 23 kilograms of traditional salt and takes 4- 6 weeks to reduce to form salt crystals.

'Marnotos' rake the traditional salt up to the bank from the bottom of the pools when the crystals begin to form, where it is left to dry in the sun for another five days.

The sea salt renaissance of southern Portugal is still young, just over twenty years old, but Portugal sea salt is becoming one of the best artisan salts you can buy, and would make a perfect gift for anyone into gourmet cooking – something to remember when putting your Xmas shopping list together!